Mtn Home AFB Weather Records (USW00024106)
Record envelope, standing records and threshold days for Mtn Home AFB (USW00024106), Idaho, United States, with 78 years of record.
Key Facts for Mtn Home AFB
- Mtn Home AFB (USW00024106) is a weather station in Idaho, United States at 43.05 latitude and -115.87 longitude, 913 m (2,996 ft) above sea level.
- The station reports from 1949 to 2026, 78 years of record.
- 1,464 records set at Mtn Home AFB still stand.
- Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
- Mtn Home AFB tied a daily record high maximum temperature of 31.1 C (88.0 F) on 7 October 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Idaho, United States, 43.05 latitude, -115.87 longitude.
- Elevation: 913 m (2,996 ft).
- Period of record: 1949 to 2026, 78 years.
- Eligible elements: tmax, tmin, prcp.
Daily Record Envelope and 2026
34 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 17.8 C (64.0 F) | -30.0 C (-22.0 F) | 12.8 C (55.0 F) | -10.6 C (12.9 F) |
| Feb | 20.0 C (68.0 F) | -22.8 C (-9.0 F) | 16.1 C (61.0 F) | -7.8 C (18.0 F) |
| Mar | 28.3 C (82.9 F) | -12.2 C (10.0 F) | 28.3 C (82.9 F) | -6.1 C (21.0 F) |
| Apr | 32.2 C (90.0 F) | -8.3 C (17.1 F) | 29.4 C (84.9 F) | -4.4 C (24.1 F) |
| May | 37.8 C (100.0 F) | -5.0 C (23.0 F) | 36.1 C (97.0 F) | 3.3 C (37.9 F) |
| Jun | 42.8 C (109.0 F) | 0.0 C (32.0 F) | 36.1 C (97.0 F) | 2.8 C (37.0 F) |
| Jul | 42.8 C (109.0 F) | 3.9 C (39.0 F) | 41.1 C (106.0 F) | 11.7 C (53.1 F) |
| Aug | 42.2 C (108.0 F) | 2.8 C (37.0 F) | 40.6 C (105.1 F) | 6.1 C (43.0 F) |
| Sep | 40.0 C (104.0 F) | -4.4 C (24.1 F) | 33.3 C (91.9 F) | 2.2 C (36.0 F) |
| Oct | 33.9 C (93.0 F) | -12.8 C (9.0 F) | 32.2 C (90.0 F) | 0.0 C (32.0 F) |
| Nov | 22.8 C (73.0 F) | -20.6 C (-5.1 F) | n/a | n/a |
| Dec | 17.8 C (64.0 F) | -22.7 C (-8.9 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1949 | 25 |
| 1951 | 18 |
| 1952 | 41 |
| 1953 | 53 |
| 1954 | 57 |
| 1955 | 57 |
| 1956 | 49 |
| 1957 | 32 |
| 1958 | 40 |
| 1959 | 35 |
| 1960 | 47 |
| 1961 | 44 |
| 1962 | 49 |
| 1963 | 49 |
| 1964 | 46 |
| 1965 | 51 |
| 1966 | 45 |
| 1967 | 39 |
| 1968 | 36 |
| 1969 | 33 |
| 1970 | 47 |
| 2011 | 12 |
| 2012 | 35 |
| 2013 | 42 |
| 2014 | 37 |
| 2015 | 60 |
| 2016 | 48 |
| 2017 | 48 |
| 2018 | 20 |
| 2019 | 33 |
| 2020 | 37 |
| 2021 | 21 |
| 2022 | 41 |
| 2023 | 31 |
| 2024 | 38 |
| 2025 | 42 |
| 2026 | 26 |
All-Time Record Progression
1 new records| Date | Kind | Detail |
|---|---|---|
| 2021-07-27 | Record high minimum temperature | Record high minimum temperature 27.2 C (81.0 F) |
Wettest Day of Each Month
Aug: 32.8 mm (1.3 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 16.5 mm (0.6 in) | 17 January 1953 |
| Feb | 12.7 mm (0.5 in) | 8 February 1960 |
| Mar | 16.3 mm (0.6 in) | 7 March 1960 |
| Apr | 21.3 mm (0.8 in) | 28 April 1951 |
| May | 22.4 mm (0.9 in) | 19 May 1953 |
| Jun | 28.7 mm (1.1 in) | 6 June 1968 |
| Jul | 32.0 mm (1.3 in) | 31 July 2021 |
| Aug | 32.8 mm (1.3 in) | 5 August 1970 |
| Sep | 16.5 mm (0.6 in) | 16 September 1961 |
| Oct | 22.6 mm (0.9 in) | 5 October 2011 |
| Nov | 19.1 mm (0.8 in) | 3 November 1968 |
| Dec | 15.2 mm (0.6 in) | 23 December 1968 |
Period of Record Coverage
1949 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1949 | 214 | 59% | No |
| 1951 | 260 | 71% | No |
| 1952 | 366 | 100% | 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 | 364 | 100% | Yes |
| 1967 | 363 | 99% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 273 | 75% | No |
| 1970 | 365 | 100% | Yes |
| 2011 | 90 | 25% | No |
| 2012 | 359 | 98% | Yes |
| 2013 | 347 | 95% | Yes |
| 2014 | 349 | 96% | Yes |
| 2015 | 352 | 96% | Yes |
| 2016 | 358 | 98% | Yes |
| 2017 | 355 | 97% | Yes |
| 2018 | 305 | 84% | No |
| 2019 | 235 | 64% | No |
| 2020 | 366 | 100% | Yes |
| 2021 | 361 | 99% | Yes |
| 2022 | 363 | 99% | Yes |
| 2023 | 362 | 99% | Yes |
| 2024 | 363 | 99% | Yes |
| 2025 | 362 | 99% | Yes |
| 2026 | 286 | 78% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 7 October 2026 | Mtn Home AFB, US | daily high max (Tie, Provisional) | 31.1 C (88.0 F) | tie | 1 year | 1 of 100 (Routine) |
| 6 October 2026 | Mtn Home AFB, US | daily high max (Provisional) | 30.6 C (87.1 F) | 2.3 C (4.1 F) | 72 years | 31 of 100 (Routine) |
| 5 October 2026 | Mtn Home AFB, US | daily high max (Provisional) | 32.2 C (90.0 F) | 1.6 C (2.9 F) | 68 years | 29 of 100 (Routine) |
| 5 October 2026 | Mtn Home AFB, US | daily high min (Tie, Provisional) | 10.6 C (51.1 F) | tie | 63 years | 6 of 100 (Routine) |
| 7 September 2026 | Mtn Home AFB, US | daily low max (Tie, Provisional) | 21.7 C (71.1 F) | tie | 60 years | 6 of 100 (Routine) |
| 5 September 2026 | Mtn Home AFB, US | daily rain (Tie, Provisional) | 0.3 mm (0.01 in) | tie | 59 years | 6 of 100 (Routine) |
| 27 August 2026 | Mtn Home AFB, US | daily high min (Provisional) | 20.0 C (68.0 F) | 1.1 C (2.0 F) | 59 years | 27 of 100 (Routine) |
| 25 August 2026 | Mtn Home AFB, US | daily high max (Tie, Provisional) | 37.2 C (99.0 F) | tie | 68 years | 6 of 100 (Routine) |
| 24 August 2026 | Mtn Home AFB, US | daily rain (Provisional) | 0.3 mm (0.01 in) | 0.3 mm (0.01 in) | 76 years | 20 of 100 (Routine) |
| 22 August 2026 | Mtn Home AFB, US | daily high min (Provisional) | 21.1 C (70.0 F) | 1.1 C (2.0 F) | 4 years | 11 of 100 (Routine) |
| 20 August 2026 | Mtn Home AFB, US | daily high max (Provisional) | 39.4 C (102.9 F) | 1.6 C (2.9 F) | 59 years | 27 of 100 (Routine) |
| 15 August 2026 | Mtn Home AFB, US | daily rain | 0.3 mm (0.01 in) | 0.3 mm (0.01 in) | 76 years | 20 of 100 (Routine) |
| 8 August 2026 | Mtn Home AFB, US | daily high max (Tie) | 38.3 C (100.9 F) | tie | 8 years | 2 of 100 (Routine) |
| 7 August 2026 | Mtn Home AFB, US | daily high max (Tie) | 40.6 C (105.1 F) | tie | 13 years | 2 of 100 (Routine) |
| 6 August 2026 | Mtn Home AFB, US | daily high max | 39.4 C (102.9 F) | 1.1 C (2.0 F) | 7 years | 11 of 100 (Routine) |
| 5 August 2026 | Mtn Home AFB, US | daily low min | 9.4 C (48.9 F) | 1.7 C (3.1 F) | 64 years | 30 of 100 (Routine) |
| 4 August 2026 | Mtn Home AFB, US | daily low min | 9.4 C (48.9 F) | 1.2 C (2.2 F) | 60 years | 28 of 100 (Routine) |
| 1 August 2026 | Mtn Home AFB, US | daily high max (Tie) | 40.0 C (104.0 F) | tie | 11 years | 2 of 100 (Routine) |
| 25 July 2026 | Mtn Home AFB, US | daily high max | 41.1 C (106.0 F) | 1.7 C (3.1 F) | 8 years | 13 of 100 (Routine) |
| 24 July 2026 | Mtn Home AFB, US | daily high max | 40.6 C (105.1 F) | 0.6 C (1.1 F) | 1 year | 8 of 100 (Routine) |
Climate Trend
30 complete years, 1952 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1952 | 10.4 C | -0.61 C |
| 1953 | 11.6 C | +0.62 C |
| 1954 | 11.4 C | +0.38 C |
| 1955 | 9.7 C | -1.24 C |
| 1956 | 10.8 C | -0.14 C |
| 1957 | 10.9 C | -0.12 C |
| 1958 | 12.2 C | +1.19 C |
| 1959 | 11.1 C | +0.14 C |
| 1960 | 11.0 C | +0.04 C |
| 1961 | 11.0 C | 0.00 C |
| 1962 | 10.3 C | -0.69 C |
| 1963 | 10.9 C | -0.08 C |
| 1964 | 9.2 C | -1.74 C |
| 1965 | 10.4 C | -0.59 C |
| 1966 | 11.2 C | +0.20 C |
| 1967 | 10.9 C | -0.12 C |
| 1968 | 10.4 C | -0.54 C |
| 1970 | 10.5 C | -0.45 C |
| 2012 | 11.4 C | +0.45 C |
| 2013 | 10.2 C | -0.80 C |
| 2014 | 11.8 C | +0.77 C |
| 2015 | 12.1 C | +1.12 C |
| 2016 | 11.7 C | +0.71 C |
| 2017 | 10.7 C | -0.29 C |
| 2020 | 11.2 C | +0.22 C |
| 2021 | 11.8 C | +0.78 C |
| 2022 | 10.1 C | -0.90 C |
| 2023 | 10.8 C | -0.23 C |
| 2024 | 11.7 C | +0.70 C |
| 2025 | 12.2 C | +1.24 C |
The fitted trend in annual mean temperature here over 1952 to 2025 is 0.08 C (-0.01 to 0.17) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.15 F (-0.01 to 0.31) per decade. The slope is a straight line fitted to 30 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.08 C (-0.01 to 0.17) per decade | 0.15 F (-0.01 to 0.31) per decade | 1952 to 2025 | 30 | Not clearly different from zero |
| Mean daily maximum | 0.2 C (0.1 to 0.3) per decade | 0.3 F (0.1 to 0.5) per decade | 1952 to 2025 | 30 | Rise |
| Mean daily minimum | -0.01 C (-0.09 to 0.07) per decade | -0.01 F (-0.16 to 0.13) per decade | 1952 to 2025 | 30 | Not clearly different from zero |
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
1949 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 42.8 C (109.0 F) | 1960 | 40.6 C (105.1 F) | 37 |
| Coldest night (TNn) | -30.0 C (-22.0 F) | 1962 | -17.1 C (1.2 F) | 37 |
| Wettest day (Rx1day) | 32.8 mm (1.3 in) | 1970 | 15.5 mm (0.6 in) | 37 |
| Wettest five days (Rx5day) | 63.7 mm (2.5 in) | 1968 | 23.4 mm (0.9 in) | 37 |
| Longest dry spell (CDD) | 106 days | 1957 | 56 days | 37 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1949 | 41.1 C (106.0 F) |
| 1951 | 40.0 C (104.0 F) |
| 1952 | 37.2 C (99.0 F) |
| 1953 | 40.0 C (104.0 F) |
| 1954 | 40.0 C (104.0 F) |
| 1955 | 40.0 C (104.0 F) |
| 1956 | 41.1 C (106.0 F) |
| 1957 | 39.4 C (102.9 F) |
| 1958 | 40.0 C (104.0 F) |
| 1959 | 41.7 C (107.1 F) |
| 1960 | 42.8 C (109.0 F) |
| 1961 | 41.1 C (106.0 F) |
| 1962 | 39.4 C (102.9 F) |
| 1963 | 38.9 C (102.0 F) |
| 1964 | 37.8 C (100.0 F) |
| 1965 | 38.9 C (102.0 F) |
| 1966 | 38.3 C (100.9 F) |
| 1967 | 41.7 C (107.1 F) |
| 1968 | 40.6 C (105.1 F) |
| 1969 | 42.2 C (108.0 F) |
| 1970 | 38.9 C (102.0 F) |
| 2011 | 31.1 C (88.0 F) |
| 2012 | 41.7 C (107.1 F) |
| 2013 | 41.7 C (107.1 F) |
| 2014 | 40.6 C (105.1 F) |
| 2015 | 42.8 C (109.0 F) |
| 2016 | 39.4 C (102.9 F) |
| 2017 | 40.6 C (105.1 F) |
| 2018 | 42.2 C (108.0 F) |
| 2019 | 39.4 C (102.9 F) |
| 2020 | 41.1 C (106.0 F) |
| 2021 | 41.1 C (106.0 F) |
| 2022 | 40.0 C (104.0 F) |
| 2023 | 41.1 C (106.0 F) |
| 2024 | 42.8 C (109.0 F) |
| 2025 | 40.6 C (105.1 F) |
| 2026 | 41.1 C (106.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1949 | -5.0 C (23.0 F) |
| 1951 | -19.4 C (-2.9 F) |
| 1952 | -22.2 C (-8.0 F) |
| 1953 | -9.4 C (15.1 F) |
| 1954 | -13.9 C (7.0 F) |
| 1955 | -20.6 C (-5.1 F) |
| 1956 | -23.3 C (-9.9 F) |
| 1957 | -21.1 C (-6.0 F) |
| 1958 | -13.3 C (8.1 F) |
| 1959 | -19.4 C (-2.9 F) |
| 1960 | -19.4 C (-2.9 F) |
| 1961 | -18.3 C (-0.9 F) |
| 1962 | -30.0 C (-22.0 F) |
| 1963 | -23.3 C (-9.9 F) |
| 1964 | -18.9 C (-2.0 F) |
| 1965 | -13.3 C (8.1 F) |
| 1966 | -17.8 C (0.0 F) |
| 1967 | -20.6 C (-5.1 F) |
| 1968 | -15.6 C (3.9 F) |
| 1969 | -12.8 C (9.0 F) |
| 1970 | -12.8 C (9.0 F) |
| 2011 | -15.5 C (4.1 F) |
| 2012 | -17.1 C (1.2 F) |
| 2013 | -22.7 C (-8.9 F) |
| 2014 | -16.6 C (2.1 F) |
| 2015 | -18.2 C (-0.8 F) |
| 2016 | -18.2 C (-0.8 F) |
| 2017 | -27.7 C (-17.9 F) |
| 2018 | -14.3 C (6.3 F) |
| 2019 | -12.8 C (9.0 F) |
| 2020 | -12.1 C (10.2 F) |
| 2021 | -12.7 C (9.1 F) |
| 2022 | -16.6 C (2.1 F) |
| 2023 | -14.3 C (6.3 F) |
| 2024 | -22.1 C (-7.8 F) |
| 2025 | -15.0 C (5.0 F) |
| 2026 | -10.6 C (12.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1949 | 11.9 mm (0.5 in) |
| 1951 | 21.3 mm (0.8 in) |
| 1952 | 17.8 mm (0.7 in) |
| 1953 | 22.4 mm (0.9 in) |
| 1954 | 17.5 mm (0.7 in) |
| 1955 | 14.0 mm (0.6 in) |
| 1956 | 11.4 mm (0.4 in) |
| 1957 | 15.0 mm (0.6 in) |
| 1958 | 17.5 mm (0.7 in) |
| 1959 | 13.2 mm (0.5 in) |
| 1960 | 16.3 mm (0.6 in) |
| 1961 | 16.5 mm (0.6 in) |
| 1962 | 22.1 mm (0.9 in) |
| 1963 | 15.5 mm (0.6 in) |
| 1964 | 18.8 mm (0.7 in) |
| 1965 | 17.0 mm (0.7 in) |
| 1966 | 11.4 mm (0.4 in) |
| 1967 | 15.2 mm (0.6 in) |
| 1968 | 28.7 mm (1.1 in) |
| 1969 | 21.3 mm (0.8 in) |
| 1970 | 32.8 mm (1.3 in) |
| 2011 | 22.6 mm (0.9 in) |
| 2012 | 13.0 mm (0.5 in) |
| 2013 | 11.4 mm (0.4 in) |
| 2014 | 15.5 mm (0.6 in) |
| 2015 | 8.4 mm (0.33 in) |
| 2016 | 10.4 mm (0.4 in) |
| 2017 | 11.9 mm (0.5 in) |
| 2018 | 11.4 mm (0.4 in) |
| 2019 | 16.0 mm (0.6 in) |
| 2020 | 12.2 mm (0.5 in) |
| 2021 | 32.0 mm (1.3 in) |
| 2022 | 14.7 mm (0.6 in) |
| 2023 | 18.5 mm (0.7 in) |
| 2024 | 9.1 mm (0.36 in) |
| 2025 | 11.2 mm (0.4 in) |
| 2026 | 11.2 mm (0.4 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1949 | 11.9 mm (0.5 in) |
| 1951 | 21.3 mm (0.8 in) |
| 1952 | 23.9 mm (0.9 in) |
| 1953 | 40.4 mm (1.6 in) |
| 1954 | 23.4 mm (0.9 in) |
| 1955 | 18.9 mm (0.7 in) |
| 1956 | 18.1 mm (0.7 in) |
| 1957 | 26.9 mm (1.1 in) |
| 1958 | 25.4 mm (1.0 in) |
| 1959 | 17.3 mm (0.7 in) |
| 1960 | 20.4 mm (0.8 in) |
| 1961 | 23.3 mm (0.9 in) |
| 1962 | 31.0 mm (1.2 in) |
| 1963 | 35.9 mm (1.4 in) |
| 1964 | 21.9 mm (0.9 in) |
| 1965 | 24.0 mm (0.9 in) |
| 1966 | 21.4 mm (0.8 in) |
| 1967 | 35.1 mm (1.4 in) |
| 1968 | 63.7 mm (2.5 in) |
| 1969 | 21.3 mm (0.8 in) |
| 1970 | 35.8 mm (1.4 in) |
| 2011 | 35.3 mm (1.4 in) |
| 2012 | 28.2 mm (1.1 in) |
| 2013 | 11.4 mm (0.4 in) |
| 2014 | 32.7 mm (1.3 in) |
| 2015 | 12.0 mm (0.5 in) |
| 2016 | 18.8 mm (0.7 in) |
| 2017 | 20.6 mm (0.8 in) |
| 2018 | 23.6 mm (0.9 in) |
| 2019 | 37.8 mm (1.5 in) |
| 2020 | 18.0 mm (0.7 in) |
| 2021 | 61.7 mm (2.4 in) |
| 2022 | 23.7 mm (0.9 in) |
| 2023 | 22.4 mm (0.9 in) |
| 2024 | 23.8 mm (0.9 in) |
| 2025 | 18.0 mm (0.7 in) |
| 2026 | 14.2 mm (0.6 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1949 | 40 days |
| 1951 | 75 days |
| 1952 | 104 days |
| 1953 | 65 days |
| 1954 | 50 days |
| 1955 | 81 days |
| 1956 | 73 days |
| 1957 | 106 days |
| 1958 | 79 days |
| 1959 | 54 days |
| 1960 | 66 days |
| 1961 | 71 days |
| 1962 | 46 days |
| 1963 | 47 days |
| 1964 | 74 days |
| 1965 | 33 days |
| 1966 | 101 days |
| 1967 | 48 days |
| 1968 | 64 days |
| 1969 | 86 days |
| 1970 | 24 days |
| 2011 | 40 days |
| 2012 | 76 days |
| 2013 | 29 days |
| 2014 | 42 days |
| 2015 | 37 days |
| 2016 | 55 days |
| 2017 | 61 days |
| 2018 | 92 days |
| 2019 | 40 days |
| 2020 | 56 days |
| 2021 | 47 days |
| 2022 | 54 days |
| 2023 | 45 days |
| 2024 | 47 days |
| 2025 | 58 days |
| 2026 | 64 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
30 years with a frostAcross 30 years with a frost, the median last spring frost at Mtn Home AFB falls on 6 May and the median first autumn frost on 9 October, which leaves a median of 159 days between them.
Fitted over all years, the growing season changes by +1.8 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1952 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 6 May | n/a | 6 May | n/a | -0.5 days per decade |
| First autumn frost | 9 October | n/a | 9 October | n/a | +1.3 days per decade |
| Growing days | 159 days | n/a | 159 days | n/a | +1.8 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
32 years, 1952 to 2025A day with at least 14.7 mm (0.6 in) of rain is expected about once in 2 years. A day with at least 39.2 mm (1.5 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 14.7 mm (0.6 in) | |
| 5 years | 19.7 mm (0.8 in) | |
| 10 years | 23.6 mm (0.9 in) | |
| 25 years | 29.2 mm (1.1 in) | |
| 50 years | 33.9 mm (1.3 in) | Longer than the 32 years of record |
| 100 years | 39.2 mm (1.5 in) | Longer than the 32 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, 32 years of values from 1952 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: 32.8 mm (1.3 in) in 1970; 32.0 mm (1.3 in) in 2021; 28.7 mm (1.1 in) in 1968.
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).