Dayton 1 WSW Threshold Days by Year (USC00452030)

19 fixed thresholds counted per year at Dayton 1 WSW (USC00452030): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Dayton 1 WSW Thresholds

Dayton 1 WSW: days with a maximum temperature at or above 30 C (86 F) in 118 years, most in 1922 with 76.
Dayton 1 WSW: days with a maximum temperature at or above 90 F (32.2 C) in 118 years, most in 1958 with 64.
Dayton 1 WSW: days with a maximum temperature at or below 0 C (32 F) in 118 years, most in 1985 with 65.
Dayton 1 WSW: days with a maximum temperature at or above 35 C (95 F) in 117 years, most in 1958 with 32.
19 fixed thresholds have at least one qualifying day at Dayton 1 WSW.

Days at or above 30 C (86 F)

118 years with a qualifying day

Days per year at Dayton 1 WSW with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 76 in 1922.

Days at or above 30 C (86 F) per year at Dayton 1 WSW
Year	Days	Decade average
1899	35	35
1900	39	38.4
1904	42	38.4
1905	34	38.4
1908	46	38.4
1909	31	38.4
1910	32	42.5
1911	27	42.5
1912	27	42.5
1913	27	42.5
1914	33	42.5
1915	51	42.5
1916	39	42.5
1917	69	42.5
1918	61	42.5
1919	59	42.5
1920	58	52.7
1921	58	52.7
1922	76	52.7
1923	45	52.7
1924	41	52.7
1925	55	52.7
1926	60	52.7
1927	41	52.7
1928	43	52.7
1929	50	52.7
1930	49	53.1
1931	51	53.1
1932	45	53.1
1933	43	53.1
1934	66	53.1
1935	58	53.1
1936	57	53.1
1937	49	53.1
1938	61	53.1
1939	52	53.1
1940	58	47
1941	40	47
1942	49	47
1943	55	47
1944	56	47
1945	57	47
1946	40	47
1947	43	47
1948	33	47
1949	39	47
1950	48	48.1
1951	51	48.1
1952	63	48.1
1953	51	48.1
1954	40	48.1
1955	39	48.1
1956	42	48.1
1957	34	48.1
1958	76	48.1
1959	37	48.1
1960	52	47.4
1961	62	47.4
1962	35	47.4
1963	49	47.4
1964	28	47.4
1965	37	47.4
1966	44	47.4
1967	71	47.4
1968	43	47.4
1969	53	47.4
1970	59	51.1
1971	52	51.1
1972	49	51.1
1973	41	51.1
1974	61	51.1
1975	42	51.1
1976	45	51.1
1977	55	51.1
1978	40	51.1
1979	67	51.1
1980	37	49.5
1981	49	49.5
1982	48	49.5
1983	49	49.5
1984	51	49.5
1985	49	49.5
1986	59	49.5
1987	58	49.5
1988	53	49.5
1989	42	49.5
1990	57	49.5
1991	48	49.5
1992	52	49.5
1993	35	49.5
1994	57	49.5
1995	37	49.5
1996	46	49.5
1997	48	49.5
1998	63	49.5
1999	52	49.5
2000	35	54
2001	59	54
2002	53	54
2003	67	54
2004	54	54
2009	56	54
2010	43	49.2
2011	44	49.2
2012	44	49.2
2013	69	49.2
2014	54	49.2
2016	43	49.2
2017	62	49.2
2018	45	49.2
2019	39	49.2
2020	46	52.9
2021	60	52.9
2022	55	52.9
2023	52	52.9
2024	52	52.9
2025	55	52.9
2026	50	52.9

For each year, a bar from the first to the last day at Dayton 1 WSW meeting 30 C (86 F).

First to last qualifying date each year at Dayton 1 WSW
Year	First date	Last date
1899	1899-06-16	1899-09-26
1900	1900-05-04	1900-08-17
1904	1904-06-27	1904-10-01
1905	1905-07-06	1905-09-23
1908	1908-05-06	1908-09-13
1909	1909-06-01	1909-09-16
1910	1910-05-09	1910-08-20
1911	1911-06-11	1911-10-08
1912	1912-05-14	1912-08-24
1913	1913-06-01	1913-09-17
1914	1914-06-16	1914-09-02
1915	1915-06-20	1915-09-17
1916	1916-06-13	1916-09-21
1917	1917-06-13	1917-10-04
1918	1918-05-03	1918-09-28
1919	1919-05-21	1919-09-25
1920	1920-06-21	1920-09-16
1921	1921-05-24	1921-09-17
1922	1922-05-16	1922-09-20
1923	1923-05-08	1923-09-13
1924	1924-05-10	1924-09-13
1925	1925-05-06	1925-08-31
1926	1926-04-15	1926-08-28
1927	1927-06-05	1927-08-23
1928	1928-05-19	1928-09-23
1929	1929-05-19	1929-09-16
1930	1930-06-06	1930-09-18
1931	1931-05-12	1931-09-06
1932	1932-06-13	1932-09-17
1933	1933-05-26	1933-09-04
1934	1934-04-20	1934-10-11
1935	1935-06-04	1935-10-10
1936	1936-04-17	1936-09-29
1937	1937-05-02	1937-09-18
1938	1938-05-23	1938-09-23
1939	1939-05-13	1939-09-20
1940	1940-05-09	1940-09-26
1941	1941-05-11	1941-08-22
1942	1942-05-21	1942-09-27
1943	1943-06-08	1943-10-08
1944	1944-05-27	1944-09-12
1945	1945-06-18	1945-09-14
1946	1946-04-25	1946-09-11
1947	1947-05-06	1947-09-24
1948	1948-05-26	1948-09-14
1949	1949-05-10	1949-09-09
1950	1950-06-28	1950-09-23
1951	1951-05-22	1951-09-18
1952	1952-05-24	1952-09-26
1953	1953-05-05	1953-09-15
1954	1954-05-17	1954-09-26
1955	1955-06-08	1955-09-10
1956	1956-05-17	1956-09-17
1957	1957-05-29	1957-09-25
1958	1958-05-19	1958-10-04
1959	1959-05-14	1959-09-14
1960	1960-06-11	1960-10-06
1961	1961-05-26	1961-09-05
1962	1962-06-24	1962-09-27
1963	1963-05-21	1963-10-16
1964	1964-06-02	1964-09-17
1965	1965-06-06	1965-08-19
1966	1966-05-03	1966-09-23
1967	1967-06-16	1967-09-29
1968	1968-05-18	1968-09-11
1969	1969-05-24	1969-09-18
1970	1970-06-02	1970-09-29
1971	1971-05-12	1971-10-06
1972	1972-05-28	1972-09-05
1973	1973-05-14	1973-09-12
1974	1974-06-12	1974-09-26
1975	1975-06-01	1975-10-03
1976	1976-05-17	1976-10-01
1977	1977-04-23	1977-09-14
1978	1978-06-04	1978-09-27
1979	1979-05-23	1979-10-07
1980	1980-04-28	1980-10-08
1981	1981-06-30	1981-09-19
1982	1982-06-11	1982-09-19
1983	1983-05-24	1983-09-26
1984	1984-05-30	1984-10-09
1985	1985-05-23	1985-08-30
1986	1986-05-26	1986-09-06
1987	1987-04-28	1987-10-02
1988	1988-05-12	1988-09-15
1989	1989-06-06	1989-09-26
1990	1990-05-05	1990-09-26
1991	1991-06-11	1991-10-01
1992	1992-05-05	1992-10-01
1993	1993-05-11	1993-09-11
1994	1994-05-09	1994-09-29
1995	1995-05-30	1995-09-17
1996	1996-06-03	1996-09-29
1997	1997-05-15	1997-10-02
1998	1998-04-30	1998-09-17
1999	1999-05-07	1999-09-23
2000	2000-06-05	2000-09-15
2001	2001-05-12	2001-09-25
2002	2002-06-13	2002-09-15
2003	2003-05-30	2003-10-22
2004	2004-06-05	2004-09-01
2009	2009-05-18	2009-09-24
2010	2010-06-14	2010-09-04
2011	2011-06-23	2011-10-02
2012	2012-05-15	2012-09-20
2013	2013-05-08	2013-09-16
2014	2014-06-03	2014-09-22
2016	2016-05-04	2016-09-27
2017	2017-05-05	2017-09-14
2018	2018-04-28	2018-09-08
2019	2019-06-02	2019-09-08
2020	2020-05-30	2020-09-11
2021	2021-05-17	2021-09-08
2022	2022-06-27	2022-09-28
2023	2023-04-30	2023-09-17
2024	2024-06-09	2024-09-26
2025	2025-05-26	2025-09-25
2026	2026-06-15	2026-09-01

Every Fixed Threshold

Fixed thresholds at Dayton 1 WSW
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	118	76	1922	50
35 C (95 F): Days	117	32	1958	11
40 C (104 F): Days	55	5	1968	1
45 C (113 F): Days	1	1	1961	1
90 F (32.2 C): Days	118	64	1958	25
100 F (37.8 C): Days	98	15	1967	1
110 F (43.3 C): Days	3	1	1961	1
0 C (32 F): Ice days (max	118	65	1985	6
0 C (32 F): Frost days (min	117	143	1955	46
-10 C (14 F): Days with min	108	39	1916	6
-20 C (-4 F): Days with min	51	14	1924	3
-30 C (-22 F): Days with min	3	3	1950	2
20 C (68 F): Tropical nights (min	68	12	1900	1
25 C (77 F): Days with min	1	1	1900	1
10 mm (0.39 in): Days with 10 mm or more rain	111	24	1953	3
25 mm (0.98 in): Days with 25 mm or more rain	61	4	1948	3
50 mm (1.97 in): Days with 50 mm or more rain	3	1	1917	1
10 cm (3.9 in): Days with 10 cm or more snowfall	41	4	1936	1
25 cm (9.8 in): Days with 25 cm or more snowfall	2	1	1980	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1899.

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Data for Dayton 1 WSW threshold days by year: CSV or JSON. Field meanings are on the data page.

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). Threshold counts are computed by this site.

Data as of 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Dayton 1 WSW Threshold Days by Year (USC00452030)

Key Facts for Dayton 1 WSW Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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