Dayton Intl AP Weather Records (USW00093815)
Record envelope, standing records and threshold days for Dayton Intl AP (USW00093815), Ohio, United States, with 79 years of record.
Key Facts for Dayton Intl AP
- Dayton Intl AP (USW00093815) is a weather station in Ohio, United States at 39.91 latitude and -84.22 longitude, 303 m (993 ft) above sea level.
- The station reports from 1948 to 2026, 79 years of record.
- 1,464 records set at Dayton Intl AP still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Dayton Intl AP set a daily record high maximum temperature of 28.9 C (84.0 F) on 14 October 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Ohio, United States, 39.91 latitude, -84.22 longitude.
- Elevation: 303 m (993 ft).
- Period of record: 1948 to 2026, 79 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
12 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 21.7 C (71.1 F) | -31.7 C (-25.1 F) | 16.7 C (62.1 F) | -21.7 C (-7.1 F) |
| Feb | 24.4 C (75.9 F) | -26.7 C (-16.1 F) | 18.9 C (66.0 F) | -18.9 C (-2.0 F) |
| Mar | 30.0 C (86.0 F) | -21.7 C (-7.1 F) | 30.0 C (86.0 F) | -7.8 C (18.0 F) |
| Apr | 31.7 C (89.1 F) | -9.4 C (15.1 F) | 28.3 C (82.9 F) | -1.7 C (28.9 F) |
| May | 33.9 C (93.0 F) | -3.3 C (26.1 F) | 30.0 C (86.0 F) | 1.1 C (34.0 F) |
| Jun | 38.9 C (102.0 F) | 4.4 C (39.9 F) | 32.8 C (91.0 F) | 11.1 C (52.0 F) |
| Jul | 38.9 C (102.0 F) | 6.7 C (44.1 F) | 34.4 C (93.9 F) | 12.2 C (54.0 F) |
| Aug | 38.9 C (102.0 F) | 4.4 C (39.9 F) | 31.7 C (89.1 F) | 11.7 C (53.1 F) |
| Sep | 38.3 C (100.9 F) | 0.0 C (32.0 F) | 34.4 C (93.9 F) | 6.7 C (44.1 F) |
| Oct | 34.4 C (93.9 F) | -6.1 C (21.0 F) | 30.6 C (87.1 F) | 6.1 C (43.0 F) |
| Nov | 26.7 C (80.1 F) | -18.9 C (-2.0 F) | n/a | n/a |
| Dec | 22.2 C (72.0 F) | -28.9 C (-20.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1948 | 10 |
| 1949 | 18 |
| 1950 | 32 |
| 1951 | 26 |
| 1952 | 22 |
| 1953 | 28 |
| 1954 | 22 |
| 1955 | 17 |
| 1956 | 13 |
| 1957 | 11 |
| 1958 | 18 |
| 1959 | 22 |
| 1960 | 23 |
| 1961 | 15 |
| 1962 | 36 |
| 1963 | 38 |
| 1964 | 28 |
| 1965 | 25 |
| 1966 | 17 |
| 1967 | 29 |
| 1968 | 13 |
| 1969 | 5 |
| 1970 | 21 |
| 1971 | 21 |
| 1972 | 22 |
| 1973 | 14 |
| 1974 | 25 |
| 1975 | 12 |
| 1976 | 35 |
| 1977 | 37 |
| 1978 | 7 |
| 1979 | 22 |
| 1980 | 19 |
| 1981 | 16 |
| 1982 | 23 |
| 1983 | 21 |
| 1984 | 21 |
| 1985 | 18 |
| 1986 | 18 |
| 1987 | 14 |
| 1988 | 41 |
| 1989 | 22 |
| 1990 | 22 |
| 1991 | 26 |
| 1992 | 9 |
| 1993 | 15 |
| 1994 | 16 |
| 1995 | 13 |
| 1996 | 11 |
| 1997 | 16 |
| 1998 | 24 |
| 1999 | 14 |
| 2000 | 13 |
| 2001 | 17 |
| 2002 | 15 |
| 2003 | 5 |
| 2004 | 10 |
| 2005 | 11 |
| 2006 | 12 |
| 2007 | 24 |
| 2008 | 13 |
| 2009 | 17 |
| 2010 | 9 |
| 2011 | 16 |
| 2012 | 31 |
| 2013 | 10 |
| 2014 | 19 |
| 2015 | 27 |
| 2016 | 13 |
| 2017 | 18 |
| 2018 | 17 |
| 2019 | 21 |
| 2020 | 11 |
| 2021 | 7 |
| 2022 | 9 |
| 2023 | 14 |
| 2024 | 16 |
| 2025 | 9 |
| 2026 | 17 |
All-Time Record Progression
10 new records| Date | Kind | Detail |
|---|---|---|
| 1978-01-18 | Record snow depth | Record snow depth 38.1 cm (15.0 in) |
| 1978-01-20 | Record snow depth | Record snow depth 53.3 cm (21.0 in) |
| 1978-01-21 | Record snow depth | Record snow depth 55.9 cm (22.0 in) |
| 1978-01-26 | Record daily snowfall | Record daily snowfall 31.0 cm (12.2 in) |
| 1982-01-10 | Record low maximum temperature | Record low maximum temperature -21.1 C (-6.0 F) |
| 1985-01-20 | Record low maximum temperature | Record low maximum temperature -23.9 C (-11.0 F) |
| 1985-01-20 | Record low minimum temperature | Record low minimum temperature -31.1 C (-24.0 F) |
| 1988-07-16 | Record high minimum temperature | Record high minimum temperature 26.7 C (80.1 F) |
| 1994-01-18 | Record low minimum temperature | Record low minimum temperature -31.7 C (-25.1 F) |
| 2026-01-25 | Record daily snowfall | Record daily snowfall 31.5 cm (12.4 in) |
Wettest Day of Each Month
Jan: 105.7 mm (4.2 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 105.7 mm (4.2 in) | 21 January 1959 |
| Feb | 65.5 mm (2.6 in) | 20 February 1951 |
| Mar | 72.9 mm (2.9 in) | 4 March 1964 |
| Apr | 78.7 mm (3.1 in) | 2 April 1977 |
| May | 80.5 mm (3.2 in) | 23 May 1989 |
| Jun | 95.5 mm (3.8 in) | 5 June 1981 |
| Jul | 80.3 mm (3.2 in) | 9 July 1955 |
| Aug | 85.9 mm (3.4 in) | 5 August 1995 |
| Sep | 96.8 mm (3.8 in) | 16 September 2005 |
| Oct | 89.9 mm (3.5 in) | 5 October 1995 |
| Nov | 90.7 mm (3.6 in) | 5 November 2017 |
| Dec | 72.4 mm (2.9 in) | 30 December 1990 |
Period of Record Coverage
1948 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1948 | 365 | 100% | Yes |
| 1949 | 365 | 100% | Yes |
| 1950 | 365 | 100% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 364 | 99% | Yes |
| 1953 | 365 | 100% | Yes |
| 1954 | 365 | 100% | Yes |
| 1955 | 365 | 100% | Yes |
| 1956 | 366 | 100% | Yes |
| 1957 | 365 | 100% | Yes |
| 1958 | 365 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 365 | 100% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 366 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 365 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 365 | 100% | Yes |
| 1978 | 364 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 365 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
| 1984 | 366 | 100% | Yes |
| 1985 | 365 | 100% | Yes |
| 1986 | 365 | 100% | Yes |
| 1987 | 365 | 100% | Yes |
| 1988 | 366 | 100% | Yes |
| 1989 | 365 | 100% | Yes |
| 1990 | 365 | 100% | Yes |
| 1991 | 365 | 100% | Yes |
| 1992 | 366 | 100% | Yes |
| 1993 | 365 | 100% | Yes |
| 1994 | 365 | 100% | Yes |
| 1995 | 365 | 100% | Yes |
| 1996 | 366 | 100% | Yes |
| 1997 | 364 | 100% | Yes |
| 1998 | 365 | 100% | Yes |
| 1999 | 365 | 100% | Yes |
| 2000 | 365 | 100% | Yes |
| 2001 | 365 | 100% | Yes |
| 2002 | 365 | 100% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 366 | 100% | Yes |
| 2005 | 365 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 365 | 100% | Yes |
| 2008 | 366 | 100% | Yes |
| 2009 | 365 | 100% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 366 | 100% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 365 | 100% | Yes |
| 2016 | 366 | 100% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 365 | 100% | Yes |
| 2022 | 365 | 100% | Yes |
| 2023 | 365 | 100% | Yes |
| 2024 | 366 | 100% | Yes |
| 2025 | 365 | 100% | Yes |
| 2026 | 287 | 79% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 14 October 2026 | Dayton Intl AP, US | daily high max (Provisional) | 28.9 C (84.0 F) | 0.6 C (1.1 F) | 51 years | 23 of 100 (Routine) |
| 13 October 2026 | Dayton Intl AP, US | daily high min (Provisional) | 18.9 C (66.0 F) | 1.1 C (2.0 F) | 56 years | 25 of 100 (Routine) |
| 13 October 2026 | Dayton Intl AP, US | daily high max (Provisional) | 30.6 C (87.1 F) | 0.6 C (1.1 F) | 51 years | 23 of 100 (Routine) |
| 20 September 2026 | Dayton Intl AP, US | daily rain (Provisional) | 34.0 mm (1.3 in) | 9.4 mm (0.37 in) | 55 years | 30 of 100 (Routine) |
| 17 September 2026 | Dayton Intl AP, US | daily high min (Tie, Provisional) | 20.6 C (69.1 F) | tie | 48 years | 5 of 100 (Routine) |
| 9 September 2026 | Dayton Intl AP, US | daily high min (Provisional) | 22.2 C (72.0 F) | 1.1 C (2.0 F) | 67 years | 29 of 100 (Routine) |
| 4 September 2026 | Dayton Intl AP, US | daily high min (Provisional) | 22.8 C (73.0 F) | 0.6 C (1.1 F) | 13 years | 12 of 100 (Routine) |
| 4 September 2026 | Dayton Intl AP, US | daily high max (Tie, Provisional) | 34.4 C (93.9 F) | tie | 65 years | 6 of 100 (Routine) |
| 2 September 2026 | Dayton Intl AP, US | daily high min (Provisional) | 23.3 C (73.9 F) | 0.5 C (0.9 F) | 52 years | 23 of 100 (Routine) |
| 16 August 2026 | Dayton Intl AP, US | daily rain | 32.8 mm (1.3 in) | 4.6 mm (0.18 in) | 73 years | 32 of 100 (Routine) |
| 11 August 2026 | Dayton Intl AP, US | daily rain | 55.6 mm (2.2 in) | 18.8 mm (0.7 in) | 47 years | 36 of 100 (Notable) |
| 1 August 2026 | Dayton Intl AP, US | daily rain | 55.9 mm (2.2 in) | 0.3 mm (0.01 in) | 72 years | 28 of 100 (Routine) |
| 23 July 2026 | Dayton Intl AP, US | daily low max (Tie) | 23.9 C (75.0 F) | tie | 44 years | 5 of 100 (Routine) |
| 10 July 2026 | Dayton Intl AP, US | daily rain | 25.4 mm (1.0 in) | 0.3 mm (0.01 in) | 76 years | 30 of 100 (Routine) |
| 26 June 2026 | Dayton Intl AP, US | daily low max (Tie) | 22.8 C (73.0 F) | tie | 32 years | 4 of 100 (Routine) |
| 22 May 2026 | Dayton Intl AP, US | daily rain | 28.4 mm (1.1 in) | 2.0 mm (0.08 in) | 72 years | 30 of 100 (Routine) |
| 15 April 2026 | Dayton Intl AP, US | daily high min | 18.3 C (64.9 F) | 2.2 C (4.0 F) | 53 years | 27 of 100 (Routine) |
| 15 April 2026 | Dayton Intl AP, US | daily high max (Tie) | 27.8 C (82.0 F) | tie | 24 years | 3 of 100 (Routine) |
| 14 April 2026 | Dayton Intl AP, US | daily high min | 18.3 C (64.9 F) | 3.9 C (7.0 F) | 59 years | 31 of 100 (Routine) |
| 14 April 2026 | Dayton Intl AP, US | daily high max | 28.3 C (82.9 F) | 1.1 C (2.0 F) | 1 year | 8 of 100 (Routine) |
Climate Trend
78 complete years, 1948 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1948 | 11.0 C | -0.33 C |
| 1949 | 12.0 C | +0.66 C |
| 1950 | 10.3 C | -1.07 C |
| 1951 | 10.7 C | -0.63 C |
| 1952 | 11.7 C | +0.40 C |
| 1953 | 12.3 C | +1.00 C |
| 1954 | 12.0 C | +0.67 C |
| 1955 | 11.7 C | +0.36 C |
| 1956 | 11.4 C | +0.02 C |
| 1957 | 11.4 C | +0.02 C |
| 1958 | 9.9 C | -1.45 C |
| 1959 | 11.6 C | +0.28 C |
| 1960 | 10.5 C | -0.85 C |
| 1961 | 10.8 C | -0.51 C |
| 1962 | 10.6 C | -0.78 C |
| 1963 | 10.1 C | -1.25 C |
| 1964 | 11.9 C | +0.58 C |
| 1965 | 11.6 C | +0.22 C |
| 1966 | 10.8 C | -0.58 C |
| 1967 | 10.8 C | -0.54 C |
| 1968 | 10.7 C | -0.63 C |
| 1969 | 10.7 C | -0.64 C |
| 1970 | 11.4 C | +0.07 C |
| 1971 | 11.6 C | +0.22 C |
| 1972 | 10.3 C | -1.00 C |
| 1973 | 12.3 C | +0.92 C |
| 1974 | 11.1 C | -0.23 C |
| 1975 | 11.7 C | +0.40 C |
| 1976 | 10.2 C | -1.17 C |
| 1977 | 11.0 C | -0.30 C |
| 1978 | 10.0 C | -1.36 C |
| 1979 | 10.3 C | -1.06 C |
| 1980 | 10.4 C | -0.98 C |
| 1981 | 10.7 C | -0.59 C |
| 1982 | 10.8 C | -0.49 C |
| 1983 | 10.8 C | -0.58 C |
| 1984 | 10.3 C | -1.02 C |
| 1985 | 10.6 C | -0.73 C |
| 1986 | 11.6 C | +0.26 C |
| 1987 | 11.9 C | +0.61 C |
| 1988 | 11.0 C | -0.34 C |
| 1989 | 10.6 C | -0.77 C |
| 1990 | 12.1 C | +0.76 C |
| 1991 | 12.4 C | +1.02 C |
| 1992 | 11.0 C | -0.32 C |
| 1993 | 10.8 C | -0.52 C |
| 1994 | 11.3 C | -0.02 C |
| 1995 | 10.9 C | -0.43 C |
| 1996 | 10.2 C | -1.10 C |
| 1997 | 10.4 C | -0.96 C |
| 1998 | 12.8 C | +1.50 C |
| 1999 | 11.9 C | +0.58 C |
| 2000 | 10.8 C | -0.49 C |
| 2001 | 11.8 C | +0.45 C |
| 2002 | 11.7 C | +0.41 C |
| 2003 | 10.4 C | -0.98 C |
| 2004 | 11.0 C | -0.33 C |
| 2005 | 11.1 C | -0.21 C |
| 2006 | 11.7 C | +0.36 C |
| 2007 | 11.7 C | +0.34 C |
| 2008 | 10.7 C | -0.67 C |
| 2009 | 10.8 C | -0.51 C |
| 2010 | 11.4 C | +0.11 C |
| 2011 | 11.7 C | +0.40 C |
| 2012 | 12.9 C | +1.52 C |
| 2013 | 11.3 C | -0.02 C |
| 2014 | 10.6 C | -0.78 C |
| 2015 | 11.9 C | +0.59 C |
| 2016 | 12.5 C | +1.12 C |
| 2017 | 12.2 C | +0.85 C |
| 2018 | 11.8 C | +0.45 C |
| 2019 | 12.5 C | +1.19 C |
| 2020 | 12.7 C | +1.38 C |
| 2021 | 12.8 C | +1.48 C |
| 2022 | 12.2 C | +0.86 C |
| 2023 | 13.2 C | +1.82 C |
| 2024 | 13.8 C | +2.50 C |
| 2025 | 12.0 C | +0.64 C |
The annual mean temperature here has risen by 0.2 C (0.1 to 0.2) per decade over 1948 to 2025. In Fahrenheit: 0.3 F (0.1 to 0.4) per decade. The slope is a straight line fitted to 78 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.2 C (0.1 to 0.2) per decade | 0.3 F (0.1 to 0.4) per decade | 1948 to 2025 | 78 | Rise |
| Mean daily maximum | 0.1 C (0.1 to 0.2) per decade | 0.2 F (0.1 to 0.4) per decade | 1948 to 2025 | 78 | Rise |
| Mean daily minimum | 0.2 C (0.1 to 0.2) per decade | 0.3 F (0.2 to 0.4) per decade | 1948 to 2025 | 78 | Rise |
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1948 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 38.9 C (102.0 F) | 1954 | 35.0 C (95.0 F) | 79 |
| Coldest night (TNn) | -31.7 C (-25.1 F) | 1994 | -21.1 C (-6.0 F) | 79 |
| Wettest day (Rx1day) | 105.7 mm (4.2 in) | 1959 | 55.6 mm (2.2 in) | 79 |
| Wettest five days (Rx5day) | 191.8 mm (7.6 in) | 1958 | 86.4 mm (3.4 in) | 79 |
| Longest dry spell (CDD) | 35 days | 1996 | 17 days | 79 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1948 | 36.1 C (97.0 F) |
| 1949 | 33.9 C (93.0 F) |
| 1950 | 32.2 C (90.0 F) |
| 1951 | 37.8 C (100.0 F) |
| 1952 | 36.1 C (97.0 F) |
| 1953 | 37.2 C (99.0 F) |
| 1954 | 38.9 C (102.0 F) |
| 1955 | 35.6 C (96.1 F) |
| 1956 | 36.1 C (97.0 F) |
| 1957 | 34.4 C (93.9 F) |
| 1958 | 31.7 C (89.1 F) |
| 1959 | 34.4 C (93.9 F) |
| 1960 | 34.4 C (93.9 F) |
| 1961 | 33.3 C (91.9 F) |
| 1962 | 36.7 C (98.1 F) |
| 1963 | 33.3 C (91.9 F) |
| 1964 | 37.8 C (100.0 F) |
| 1965 | 37.8 C (100.0 F) |
| 1966 | 37.2 C (99.0 F) |
| 1967 | 35.0 C (95.0 F) |
| 1968 | 33.3 C (91.9 F) |
| 1969 | 33.9 C (93.0 F) |
| 1970 | 36.7 C (98.1 F) |
| 1971 | 36.7 C (98.1 F) |
| 1972 | 36.1 C (97.0 F) |
| 1973 | 35.6 C (96.1 F) |
| 1974 | 35.0 C (95.0 F) |
| 1975 | 33.9 C (93.0 F) |
| 1976 | 34.4 C (93.9 F) |
| 1977 | 36.7 C (98.1 F) |
| 1978 | 35.6 C (96.1 F) |
| 1979 | 33.3 C (91.9 F) |
| 1980 | 38.3 C (100.9 F) |
| 1981 | 35.6 C (96.1 F) |
| 1982 | 33.9 C (93.0 F) |
| 1983 | 36.7 C (98.1 F) |
| 1984 | 33.3 C (91.9 F) |
| 1985 | 32.8 C (91.0 F) |
| 1986 | 33.9 C (93.0 F) |
| 1987 | 34.4 C (93.9 F) |
| 1988 | 38.9 C (102.0 F) |
| 1989 | 35.0 C (95.0 F) |
| 1990 | 35.0 C (95.0 F) |
| 1991 | 36.1 C (97.0 F) |
| 1992 | 33.3 C (91.9 F) |
| 1993 | 35.6 C (96.1 F) |
| 1994 | 36.7 C (98.1 F) |
| 1995 | 37.2 C (99.0 F) |
| 1996 | 34.4 C (93.9 F) |
| 1997 | 35.6 C (96.1 F) |
| 1998 | 34.4 C (93.9 F) |
| 1999 | 36.7 C (98.1 F) |
| 2000 | 31.7 C (89.1 F) |
| 2001 | 32.8 C (91.0 F) |
| 2002 | 35.0 C (95.0 F) |
| 2003 | 32.2 C (90.0 F) |
| 2004 | 31.7 C (89.1 F) |
| 2005 | 35.0 C (95.0 F) |
| 2006 | 32.8 C (91.0 F) |
| 2007 | 35.6 C (96.1 F) |
| 2008 | 34.4 C (93.9 F) |
| 2009 | 33.3 C (91.9 F) |
| 2010 | 34.4 C (93.9 F) |
| 2011 | 36.7 C (98.1 F) |
| 2012 | 38.9 C (102.0 F) |
| 2013 | 35.6 C (96.1 F) |
| 2014 | 32.8 C (91.0 F) |
| 2015 | 32.8 C (91.0 F) |
| 2016 | 33.3 C (91.9 F) |
| 2017 | 32.8 C (91.0 F) |
| 2018 | 33.9 C (93.0 F) |
| 2019 | 34.4 C (93.9 F) |
| 2020 | 35.0 C (95.0 F) |
| 2021 | 34.4 C (93.9 F) |
| 2022 | 35.0 C (95.0 F) |
| 2023 | 33.9 C (93.0 F) |
| 2024 | 36.7 C (98.1 F) |
| 2025 | 35.0 C (95.0 F) |
| 2026 | 34.4 C (93.9 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1948 | -23.3 C (-9.9 F) |
| 1949 | -16.1 C (3.0 F) |
| 1950 | -20.0 C (-4.0 F) |
| 1951 | -26.7 C (-16.1 F) |
| 1952 | -14.4 C (6.1 F) |
| 1953 | -19.4 C (-2.9 F) |
| 1954 | -15.6 C (3.9 F) |
| 1955 | -22.2 C (-8.0 F) |
| 1956 | -15.6 C (3.9 F) |
| 1957 | -21.1 C (-6.0 F) |
| 1958 | -22.8 C (-9.0 F) |
| 1959 | -23.9 C (-11.0 F) |
| 1960 | -22.2 C (-8.0 F) |
| 1961 | -22.2 C (-8.0 F) |
| 1962 | -23.9 C (-11.0 F) |
| 1963 | -28.3 C (-18.9 F) |
| 1964 | -18.9 C (-2.0 F) |
| 1965 | -21.7 C (-7.1 F) |
| 1966 | -23.3 C (-9.9 F) |
| 1967 | -20.0 C (-4.0 F) |
| 1968 | -23.9 C (-11.0 F) |
| 1969 | -17.8 C (0.0 F) |
| 1970 | -23.3 C (-9.9 F) |
| 1971 | -20.0 C (-4.0 F) |
| 1972 | -26.7 C (-16.1 F) |
| 1973 | -19.4 C (-2.9 F) |
| 1974 | -17.8 C (0.0 F) |
| 1975 | -19.4 C (-2.9 F) |
| 1976 | -21.1 C (-6.0 F) |
| 1977 | -29.4 C (-20.9 F) |
| 1978 | -20.0 C (-4.0 F) |
| 1979 | -23.9 C (-11.0 F) |
| 1980 | -21.7 C (-7.1 F) |
| 1981 | -21.1 C (-6.0 F) |
| 1982 | -27.8 C (-18.0 F) |
| 1983 | -26.1 C (-15.0 F) |
| 1984 | -28.9 C (-20.0 F) |
| 1985 | -31.1 C (-24.0 F) |
| 1986 | -19.4 C (-2.9 F) |
| 1987 | -18.9 C (-2.0 F) |
| 1988 | -20.6 C (-5.1 F) |
| 1989 | -28.9 C (-20.0 F) |
| 1990 | -16.7 C (1.9 F) |
| 1991 | -16.7 C (1.9 F) |
| 1992 | -22.2 C (-8.0 F) |
| 1993 | -21.7 C (-7.1 F) |
| 1994 | -31.7 C (-25.1 F) |
| 1995 | -20.6 C (-5.1 F) |
| 1996 | -22.2 C (-8.0 F) |
| 1997 | -21.1 C (-6.0 F) |
| 1998 | -13.9 C (7.0 F) |
| 1999 | -21.7 C (-7.1 F) |
| 2000 | -22.8 C (-9.0 F) |
| 2001 | -13.9 C (7.0 F) |
| 2002 | -17.2 C (1.0 F) |
| 2003 | -21.7 C (-7.1 F) |
| 2004 | -23.3 C (-9.9 F) |
| 2005 | -19.4 C (-2.9 F) |
| 2006 | -15.6 C (3.9 F) |
| 2007 | -21.1 C (-6.0 F) |
| 2008 | -20.0 C (-4.0 F) |
| 2009 | -25.6 C (-14.1 F) |
| 2010 | -18.9 C (-2.0 F) |
| 2011 | -21.7 C (-7.1 F) |
| 2012 | -16.1 C (3.0 F) |
| 2013 | -17.1 C (1.2 F) |
| 2014 | -24.9 C (-12.8 F) |
| 2015 | -21.6 C (-6.9 F) |
| 2016 | -17.7 C (0.1 F) |
| 2017 | -20.5 C (-4.9 F) |
| 2018 | -24.9 C (-12.8 F) |
| 2019 | -22.1 C (-7.8 F) |
| 2020 | -12.1 C (10.2 F) |
| 2021 | -18.2 C (-0.8 F) |
| 2022 | -22.7 C (-8.9 F) |
| 2023 | -10.5 C (13.1 F) |
| 2024 | -17.7 C (0.1 F) |
| 2025 | -19.9 C (-3.8 F) |
| 2026 | -21.7 C (-7.1 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1948 | 55.4 mm (2.2 in) |
| 1949 | 59.9 mm (2.4 in) |
| 1950 | 57.4 mm (2.3 in) |
| 1951 | 65.5 mm (2.6 in) |
| 1952 | 85.9 mm (3.4 in) |
| 1953 | 55.6 mm (2.2 in) |
| 1954 | 27.4 mm (1.1 in) |
| 1955 | 80.3 mm (3.2 in) |
| 1956 | 41.9 mm (1.6 in) |
| 1957 | 44.5 mm (1.8 in) |
| 1958 | 82.6 mm (3.3 in) |
| 1959 | 105.7 mm (4.2 in) |
| 1960 | 63.2 mm (2.5 in) |
| 1961 | 52.6 mm (2.1 in) |
| 1962 | 31.5 mm (1.2 in) |
| 1963 | 66.3 mm (2.6 in) |
| 1964 | 72.9 mm (2.9 in) |
| 1965 | 40.6 mm (1.6 in) |
| 1966 | 32.8 mm (1.3 in) |
| 1967 | 63.8 mm (2.5 in) |
| 1968 | 71.6 mm (2.8 in) |
| 1969 | 75.7 mm (3.0 in) |
| 1970 | 39.4 mm (1.6 in) |
| 1971 | 38.6 mm (1.5 in) |
| 1972 | 42.4 mm (1.7 in) |
| 1973 | 31.8 mm (1.3 in) |
| 1974 | 60.2 mm (2.4 in) |
| 1975 | 51.8 mm (2.0 in) |
| 1976 | 27.2 mm (1.1 in) |
| 1977 | 78.7 mm (3.1 in) |
| 1978 | 54.1 mm (2.1 in) |
| 1979 | 49.3 mm (1.9 in) |
| 1980 | 74.7 mm (2.9 in) |
| 1981 | 95.5 mm (3.8 in) |
| 1982 | 57.2 mm (2.3 in) |
| 1983 | 53.3 mm (2.1 in) |
| 1984 | 44.5 mm (1.8 in) |
| 1985 | 52.1 mm (2.1 in) |
| 1986 | 82.3 mm (3.2 in) |
| 1987 | 61.0 mm (2.4 in) |
| 1988 | 46.0 mm (1.8 in) |
| 1989 | 80.5 mm (3.2 in) |
| 1990 | 72.4 mm (2.9 in) |
| 1991 | 58.4 mm (2.3 in) |
| 1992 | 54.9 mm (2.2 in) |
| 1993 | 55.6 mm (2.2 in) |
| 1994 | 47.0 mm (1.9 in) |
| 1995 | 89.9 mm (3.5 in) |
| 1996 | 64.3 mm (2.5 in) |
| 1997 | 44.5 mm (1.8 in) |
| 1998 | 53.1 mm (2.1 in) |
| 1999 | 34.5 mm (1.4 in) |
| 2000 | 63.5 mm (2.5 in) |
| 2001 | 57.2 mm (2.3 in) |
| 2002 | 94.7 mm (3.7 in) |
| 2003 | 45.2 mm (1.8 in) |
| 2004 | 68.3 mm (2.7 in) |
| 2005 | 96.8 mm (3.8 in) |
| 2006 | 55.6 mm (2.2 in) |
| 2007 | 53.8 mm (2.1 in) |
| 2008 | 54.1 mm (2.1 in) |
| 2009 | 38.4 mm (1.5 in) |
| 2010 | 41.1 mm (1.6 in) |
| 2011 | 78.7 mm (3.1 in) |
| 2012 | 47.2 mm (1.9 in) |
| 2013 | 62.5 mm (2.5 in) |
| 2014 | 44.5 mm (1.8 in) |
| 2015 | 49.8 mm (2.0 in) |
| 2016 | 41.4 mm (1.6 in) |
| 2017 | 90.7 mm (3.6 in) |
| 2018 | 73.2 mm (2.9 in) |
| 2019 | 48.5 mm (1.9 in) |
| 2020 | 44.5 mm (1.8 in) |
| 2021 | 43.4 mm (1.7 in) |
| 2022 | 67.1 mm (2.6 in) |
| 2023 | 68.6 mm (2.7 in) |
| 2024 | 49.3 mm (1.9 in) |
| 2025 | 62.2 mm (2.4 in) |
| 2026 | 67.3 mm (2.6 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1948 | 72.7 mm (2.9 in) |
| 1949 | 69.3 mm (2.7 in) |
| 1950 | 100.8 mm (4.0 in) |
| 1951 | 84.5 mm (3.3 in) |
| 1952 | 109.0 mm (4.3 in) |
| 1953 | 68.3 mm (2.7 in) |
| 1954 | 49.0 mm (1.9 in) |
| 1955 | 89.7 mm (3.5 in) |
| 1956 | 57.9 mm (2.3 in) |
| 1957 | 112.3 mm (4.4 in) |
| 1958 | 191.8 mm (7.6 in) |
| 1959 | 124.0 mm (4.9 in) |
| 1960 | 65.0 mm (2.6 in) |
| 1961 | 73.4 mm (2.9 in) |
| 1962 | 71.9 mm (2.8 in) |
| 1963 | 88.6 mm (3.5 in) |
| 1964 | 90.7 mm (3.6 in) |
| 1965 | 91.6 mm (3.6 in) |
| 1966 | 51.5 mm (2.0 in) |
| 1967 | 64.1 mm (2.5 in) |
| 1968 | 103.1 mm (4.1 in) |
| 1969 | 83.6 mm (3.3 in) |
| 1970 | 58.9 mm (2.3 in) |
| 1971 | 58.2 mm (2.3 in) |
| 1972 | 53.3 mm (2.1 in) |
| 1973 | 76.8 mm (3.0 in) |
| 1974 | 102.3 mm (4.0 in) |
| 1975 | 94.2 mm (3.7 in) |
| 1976 | 41.2 mm (1.6 in) |
| 1977 | 84.8 mm (3.3 in) |
| 1978 | 73.4 mm (2.9 in) |
| 1979 | 82.9 mm (3.3 in) |
| 1980 | 92.7 mm (3.6 in) |
| 1981 | 106.2 mm (4.2 in) |
| 1982 | 86.6 mm (3.4 in) |
| 1983 | 84.9 mm (3.3 in) |
| 1984 | 62.0 mm (2.4 in) |
| 1985 | 87.6 mm (3.4 in) |
| 1986 | 140.8 mm (5.5 in) |
| 1987 | 87.7 mm (3.5 in) |
| 1988 | 82.3 mm (3.2 in) |
| 1989 | 149.3 mm (5.9 in) |
| 1990 | 160.6 mm (6.3 in) |
| 1991 | 73.5 mm (2.9 in) |
| 1992 | 89.0 mm (3.5 in) |
| 1993 | 121.7 mm (4.8 in) |
| 1994 | 68.9 mm (2.7 in) |
| 1995 | 161.3 mm (6.4 in) |
| 1996 | 102.2 mm (4.0 in) |
| 1997 | 86.4 mm (3.4 in) |
| 1998 | 101.9 mm (4.0 in) |
| 1999 | 51.1 mm (2.0 in) |
| 2000 | 78.3 mm (3.1 in) |
| 2001 | 73.7 mm (2.9 in) |
| 2002 | 101.8 mm (4.0 in) |
| 2003 | 113.0 mm (4.4 in) |
| 2004 | 104.2 mm (4.1 in) |
| 2005 | 131.1 mm (5.2 in) |
| 2006 | 67.6 mm (2.7 in) |
| 2007 | 92.4 mm (3.6 in) |
| 2008 | 96.3 mm (3.8 in) |
| 2009 | 47.0 mm (1.9 in) |
| 2010 | 57.2 mm (2.3 in) |
| 2011 | 110.2 mm (4.3 in) |
| 2012 | 66.6 mm (2.6 in) |
| 2013 | 81.8 mm (3.2 in) |
| 2014 | 66.5 mm (2.6 in) |
| 2015 | 92.7 mm (3.6 in) |
| 2016 | 56.9 mm (2.2 in) |
| 2017 | 114.6 mm (4.5 in) |
| 2018 | 124.5 mm (4.9 in) |
| 2019 | 84.6 mm (3.3 in) |
| 2020 | 93.8 mm (3.7 in) |
| 2021 | 65.3 mm (2.6 in) |
| 2022 | 71.4 mm (2.8 in) |
| 2023 | 80.8 mm (3.2 in) |
| 2024 | 94.3 mm (3.7 in) |
| 2025 | 118.6 mm (4.7 in) |
| 2026 | 143.5 mm (5.6 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1948 | 19 days |
| 1949 | 22 days |
| 1950 | 23 days |
| 1951 | 15 days |
| 1952 | 22 days |
| 1953 | 25 days |
| 1954 | 14 days |
| 1955 | 17 days |
| 1956 | 13 days |
| 1957 | 23 days |
| 1958 | 22 days |
| 1959 | 12 days |
| 1960 | 13 days |
| 1961 | 17 days |
| 1962 | 21 days |
| 1963 | 20 days |
| 1964 | 20 days |
| 1965 | 21 days |
| 1966 | 17 days |
| 1967 | 20 days |
| 1968 | 20 days |
| 1969 | 15 days |
| 1970 | 14 days |
| 1971 | 13 days |
| 1972 | 14 days |
| 1973 | 19 days |
| 1974 | 14 days |
| 1975 | 19 days |
| 1976 | 25 days |
| 1977 | 28 days |
| 1978 | 14 days |
| 1979 | 12 days |
| 1980 | 14 days |
| 1981 | 21 days |
| 1982 | 26 days |
| 1983 | 22 days |
| 1984 | 15 days |
| 1985 | 23 days |
| 1986 | 16 days |
| 1987 | 23 days |
| 1988 | 16 days |
| 1989 | 13 days |
| 1990 | 13 days |
| 1991 | 12 days |
| 1992 | 18 days |
| 1993 | 17 days |
| 1994 | 14 days |
| 1995 | 21 days |
| 1996 | 35 days |
| 1997 | 12 days |
| 1998 | 13 days |
| 1999 | 25 days |
| 2000 | 15 days |
| 2001 | 16 days |
| 2002 | 15 days |
| 2003 | 18 days |
| 2004 | 19 days |
| 2005 | 14 days |
| 2006 | 16 days |
| 2007 | 18 days |
| 2008 | 24 days |
| 2009 | 17 days |
| 2010 | 18 days |
| 2011 | 15 days |
| 2012 | 20 days |
| 2013 | 18 days |
| 2014 | 17 days |
| 2015 | 20 days |
| 2016 | 17 days |
| 2017 | 15 days |
| 2018 | 11 days |
| 2019 | 26 days |
| 2020 | 14 days |
| 2021 | 13 days |
| 2022 | 29 days |
| 2023 | 16 days |
| 2024 | 34 days |
| 2025 | 21 days |
| 2026 | 13 days |
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
78 years with a frostAcross 78 years with a frost, the median last spring frost at Dayton Intl AP falls on 20 April and the median first autumn frost on 23 October, which leaves a median of 184 days between them.
In 1996 to 2025 the median growing season was 191 days. That is 7 days more than in 1948 to 1977.
Fitted over all years, the growing season changes by +1.4 days per decade at this station.
| Measure | Median, all years | Earliest period (1948 to 1977) | Recent period (1996 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 20 April | 21 April | 18 April | 3 days earlier | -0.7 days per decade |
| First autumn frost | 23 October | 25 October | 27 October | 2 days later | +0.7 days per decade |
| Growing days | 184 days | 184 days | 191 days | 7 days more | +1.4 days per decade |
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
78 years, 1948 to 2025A day with at least 56.4 mm (2.2 in) of rain is expected about once in 2 years. A day with at least 110.0 mm (4.3 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 56.4 mm (2.2 in) | |
| 5 years | 72.5 mm (2.9 in) | |
| 10 years | 82.4 mm (3.2 in) | |
| 25 years | 94.1 mm (3.7 in) | |
| 50 years | 102.3 mm (4.0 in) | |
| 100 years | 110.0 mm (4.3 in) | Longer than the 78 years of record |
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 78 years of values from 1948 to 2025.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 105.7 mm (4.2 in) in 1959; 96.8 mm (3.8 in) in 2005; 95.5 mm (3.8 in) in 1981.
Station Changes
2 suspected2 changes were suspected in the annual mean temperature of Dayton Intl AP, at 1962 and 1983. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1962 ran 0.3 C (0.6 F) higher than in the years before (likely change).
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1983 ran 0.4 C (0.7 F) lower than in the years before (likely change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 1962 | +0.3 | +0.6 | likely | 5 |
| 1983 | -0.4 | -0.7 | likely | 5 |
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Climate Twins
2011 to 2025 against 1961 to 1990Over 2011 to 2025, Dayton Intl AP had a mean temperature of 12.3 C (54.1 F) and 1,046.1 mm (41.2 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Hagerstown (United States, 555 km away), Frankfort Downtown (United States, 198 km away) and Salem (United States, 215 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Hagerstown | United States | 555 km (345 mi) | 12.0 C (53.5 F) | 996.2 mm (39.2 in) | 0.62 |
| Salem | United States | 215 km (134 mi) | 12.4 C (54.4 F) | 1,133.0 mm (44.6 in) | 0.63 |
| Frankfort Downtown | United States | 198 km (123 mi) | 12.3 C (54.1 F) | 1,046.1 mm (41.2 in) | 0.63 |
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17 (17 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-17).