Unionville Threshold Days by Year (USC00238523)

21 fixed thresholds counted per year at Unionville (USC00238523): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Unionville Thresholds

Unionville: days with 10 mm (0.39 in) or more of precipitation in 107 years, most in 1909 with 50.
Unionville: days with 25 mm (0.98 in) or more of precipitation in 107 years, most in 2008 with 20.
Unionville: days with a maximum temperature at or above 30 C (86 F) in 105 years, most in 1894 with 120.
Unionville: days with a maximum temperature at or above 90 F (32.2 C) in 105 years, most in 1894 with 90.
21 fixed thresholds have at least one qualifying day at Unionville.

Days at or above 30 C (86 F)

105 years with a qualifying day

Days per year at Unionville with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 120 in 1894.

Days at or above 30 C (86 F) per year at Unionville
Year	Days	Decade average
1894	120	99.3
1895	80	99.3
1898	98	99.3
1900	103	63.6
1901	106	63.6
1902	44	63.6
1903	39	63.6
1904	35	63.6
1905	58	63.6
1906	76	63.6
1907	51	63.6
1908	65	63.6
1909	59	63.6
1910	62	68.5
1911	82	68.5
1912	67	68.5
1913	90	68.5
1914	77	68.5
1915	24	68.5
1916	69	68.5
1917	54	68.5
1918	80	68.5
1919	80	68.5
1920	56	61.7
1921	85	61.7
1922	72	61.7
1923	61	61.7
1924	37	61.7
1925	78	61.7
1926	67	61.7
1927	62	61.7
1928	47	61.7
1929	52	61.7
1930	80	89.3
1931	87	89.3
1932	57	89.3
1933	99	89.3
1934	101	89.3
1935	66	89.3
1936	98	89.3
1938	102	89.3
1939	114	89.3
1940	80	67.4
1941	88	67.4
1942	62	67.4
1943	81	67.4
1944	99	67.4
1945	49	67.4
1946	45	67.4
1947	59	67.4
1948	62	67.4
1949	49	67.4
1950	29	51.6
1951	16	51.6
1952	47	51.6
1953	75	51.6
1954	71	51.6
1955	64	51.6
1956	77	51.6
1957	48	51.6
1958	31	51.6
1959	58	51.6
1960	48	52.7
1961	53	52.7
1962	61	52.7
1963	71	52.7
1964	63	52.7
1965	44	52.7
1966	50	52.7
1967	28	52.7
1968	53	52.7
1969	56	52.7
1970	53	56.6
1971	72	56.6
1972	61	56.6
1973	54	56.6
1974	45	56.6
1975	73	56.6
1976	61	56.6
1977	56	56.6
1978	52	56.6
1979	39	56.6
1980	74	50.7
1981	30	50.7
1984	59	50.7
1985	42	50.7
1986	45	50.7
1987	65	50.7
1989	40	50.7
1990	59	45.3
1991	58	45.3
1992	19	45.3
2005	60	45.8
2006	57	45.8
2007	64	45.8
2008	26	45.8
2009	22	45.8
2010	51	46
2011	55	46
2012	75	46
2013	45	46
2014	22	46
2015	24	46
2016	48	46
2017	48	46

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

First to last qualifying date each year at Unionville
Year	First date	Last date
1894	1894-04-17	1894-10-24
1895	1895-03-29	1895-09-22
1898	1898-05-22	1898-10-04
1900	1900-04-07	1900-10-18
1901	1901-04-26	1901-09-30
1902	1902-05-02	1902-08-20
1903	1903-06-18	1903-08-26
1904	1904-06-12	1904-09-29
1905	1905-05-30	1905-10-06
1906	1906-05-23	1906-09-19
1907	1907-03-22	1907-09-20
1908	1908-05-17	1908-09-27
1909	1909-05-06	1909-10-03
1910	1910-03-24	1910-10-15
1911	1911-05-11	1911-09-28
1912	1912-05-23	1912-10-07
1913	1913-05-03	1913-10-13
1914	1914-05-25	1914-09-20
1915	1915-05-13	1915-09-18
1916	1916-05-26	1916-10-09
1917	1917-05-19	1917-09-16
1918	1918-05-04	1918-10-04
1919	1919-05-30	1919-10-03
1920	1920-05-26	1920-10-10
1921	1921-05-20	1921-09-22
1922	1922-06-06	1922-10-04
1923	1923-05-31	1923-09-26
1924	1924-06-11	1924-08-30
1925	1925-05-20	1925-09-28
1926	1926-05-17	1926-09-21
1927	1927-05-23	1927-10-27
1928	1928-05-09	1928-10-12
1929	1929-04-04	1929-09-28
1930	1930-04-10	1930-10-10
1931	1931-05-16	1931-10-10
1932	1932-05-03	1932-10-02
1933	1933-05-19	1933-09-25
1934	1934-04-09	1934-08-31
1935	1935-06-10	1935-09-24
1936	1936-04-20	1936-09-22
1938	1938-03-21	1938-10-17
1939	1939-03-22	1939-10-25
1940	1940-04-02	1940-10-27
1941	1941-04-13	1941-09-24
1942	1942-05-26	1942-10-09
1943	1943-05-05	1943-09-11
1944	1944-05-14	1944-09-20
1945	1945-03-27	1945-09-23
1946	1946-06-06	1946-09-26
1947	1947-06-09	1947-10-07
1948	1948-06-03	1948-09-20
1949	1949-05-04	1949-10-08
1950	1950-05-05	1950-11-01
1951	1951-07-07	1951-08-31
1952	1952-05-01	1952-09-30
1953	1953-05-25	1953-10-15
1954	1954-06-11	1954-10-04
1955	1955-05-23	1955-09-18
1956	1956-04-27	1956-10-12
1957	1957-06-05	1957-09-01
1958	1958-06-04	1958-09-08
1959	1959-05-05	1959-09-08
1960	1960-06-04	1960-09-08
1961	1961-06-01	1961-09-10
1962	1962-05-05	1962-10-11
1963	1963-05-08	1963-10-14
1964	1964-05-16	1964-09-09
1965	1965-04-30	1965-09-09
1966	1966-05-05	1966-09-03
1967	1967-05-23	1967-08-29
1968	1968-05-02	1968-08-24
1969	1969-05-28	1969-10-04
1970	1970-04-28	1970-09-20
1971	1971-06-03	1971-10-01
1972	1972-05-20	1972-09-20
1973	1973-06-08	1973-09-01
1974	1974-05-16	1974-08-26
1975	1975-05-18	1975-10-13
1976	1976-06-08	1976-10-02
1977	1977-05-18	1977-09-08
1978	1978-05-25	1978-09-20
1979	1979-05-09	1979-09-12
1980	1980-04-22	1980-09-22
1981	1981-06-08	1981-10-01
1984	1984-05-18	1984-09-24
1985	1985-04-18	1985-09-19
1986	1986-03-29	1986-09-28
1987	1987-04-19	1987-09-05
1989	1989-04-24	1989-10-15
1990	1990-04-23	1990-10-07
1991	1991-05-14	1991-09-14
1992	1992-06-17	1992-08-26
2005	2005-05-19	2005-09-13
2006	2006-04-15	2006-10-04
2007	2007-04-30	2007-09-25
2008	2008-06-02	2008-09-03
2009	2009-05-24	2009-08-15
2010	2010-05-25	2010-09-21
2011	2011-05-10	2011-09-13
2012	2012-05-20	2012-09-13
2013	2013-05-15	2013-09-20
2014	2014-05-22	2014-09-05
2015	2015-06-10	2015-09-07
2016	2016-06-10	2016-10-18
2017	2017-05-16	2017-09-26

Every Fixed Threshold

Fixed thresholds at Unionville
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	105	120	1894	48
35 C (95 F): Days	93	62	1934	1
40 C (104 F): Days	19	28	1936	2
45 C (113 F): Days	2	2	1934	1
90 F (32.2 C): Days	105	90	1894	9
100 F (37.8 C): Days	45	45	1934	1
110 F (43.3 C): Days	5	14	1934	1
0 C (32 F): Ice days (max	105	72	1978	28
0 C (32 F): Frost days (min	103	167	1989	119
-10 C (14 F): Days with min	103	74	1989	27
-20 C (-4 F): Days with min	97	32	1936	6
-30 C (-22 F): Days with min	7	4	1905	3
20 C (68 F): Tropical nights (min	103	52	1936	20
25 C (77 F): Days with min	22	7	1934	1
10 mm (0.39 in): Days with 10 mm or more rain	107	50	1909	26
25 mm (0.98 in): Days with 25 mm or more rain	107	20	2008	9
50 mm (1.97 in): Days with 50 mm or more rain	91	7	2008	1
100 mm (3.94 in): Days with 100 mm or more rain	13	4	2014	1
200 mm (7.87 in): Days with 200 mm or more rain	1	1	2008	1
10 cm (3.9 in): Days with 10 cm or more snowfall	73	6	1918	1
25 cm (9.8 in): Days with 25 cm or more snowfall	13	1	1920	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1894.

Download the Data

Data for Unionville 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 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Unionville Threshold Days by Year (USC00238523)

Key Facts for Unionville Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

Related