Ottawa 4SW Threshold Days by Year (USC00116526)

20 fixed thresholds counted per year at Ottawa 4SW (USC00116526): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Ottawa 4SW Thresholds

Ottawa 4SW: days with a maximum temperature at or above 30 C (86 F) in 127 years, most in 1901 with 95.
Ottawa 4SW: days with a maximum temperature at or above 90 F (32.2 C) in 127 years, most in 1901 with 72.
Ottawa 4SW: days with a maximum temperature at or below 0 C (32 F) in 127 years, most in 1985 with 65.
Ottawa 4SW: nights with a minimum temperature at or below 0 C (32 F) in 126 years, most in 1895 with 162.
20 fixed thresholds have at least one qualifying day at Ottawa 4SW.

Days at or above 30 C (86 F)

127 years with a qualifying day

Days per year at Ottawa 4SW with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 95 in 1901.

Days at or above 30 C (86 F) per year at Ottawa 4SW
Year	Days	Decade average
1893	83	73.9
1894	85	73.9
1895	79	73.9
1896	67	73.9
1897	73	73.9
1898	50	73.9
1899	80	73.9
1900	82	54.1
1901	95	54.1
1902	48	54.1
1903	49	54.1
1904	25	54.1
1905	40	54.1
1906	62	54.1
1907	22	54.1
1908	67	54.1
1909	51	54.1
1910	57	58
1911	62	58
1912	54	58
1913	74	58
1915	33	58
1916	68	58
1922	64	54.8
1923	59	54.8
1924	26	54.8
1925	75	54.8
1926	51	54.8
1927	50	54.8
1928	58	54.8
1929	55	54.8
1930	82	74.3
1931	78	74.3
1932	64	74.3
1933	87	74.3
1934	95	74.3
1935	69	74.3
1936	92	74.3
1937	66	74.3
1938	50	74.3
1939	60	74.3
1940	74	69.1
1941	84	69.1
1942	64	69.1
1943	73	69.1
1944	83	69.1
1945	52	69.1
1946	73	69.1
1947	78	69.1
1948	50	69.1
1949	60	69.1
1950	44	54.4
1951	38	54.4
1952	69	54.4
1953	71	54.4
1954	61	54.4
1955	73	54.4
1956	55	54.4
1957	43	54.4
1958	26	54.4
1959	64	54.4
1960	42	56
1961	53	56
1962	67	56
1963	66	56
1964	66	56
1965	50	56
1966	59	56
1967	42	56
1968	59	56
1969	56	56
1970	60	63
1971	80	63
1972	49	63
1973	51	63
1974	48	63
1975	64	63
1976	67	63
1977	75	63
1978	76	63
1979	60	63
1980	75	44.2
1981	49	44.2
1982	57	44.2
1983	61	44.2
1984	33	44.2
1985	21	44.2
1986	23	44.2
1987	46	44.2
1988	54	44.2
1989	23	44.2
1990	24	39.3
1991	61	39.3
1992	17	39.3
1993	22	39.3
1994	41	39.3
1995	51	39.3
1996	31	39.3
1997	36	39.3
1998	44	39.3
1999	66	39.3
2000	53	44.2
2001	60	44.2
2002	70	44.2
2003	43	44.2
2004	30	44.2
2005	73	44.2
2006	34	44.2
2008	23	44.2
2009	12	44.2
2010	60	41.3
2011	52	41.3
2012	70	41.3
2013	41	41.3
2014	32	41.3
2015	24	41.3
2016	30	41.3
2017	30	41.3
2018	47	41.3
2019	27	41.3
2020	25	32.9
2021	43	32.9
2022	27	32.9
2023	33	32.9
2024	29	32.9
2025	47	32.9
2026	26	32.9

For each year, a bar from the first to the last day at Ottawa 4SW meeting 30 C (86 F).

First to last qualifying date each year at Ottawa 4SW
Year	First date	Last date
1893	1893-04-07	1893-09-21
1894	1894-04-17	1894-09-14
1895	1895-04-25	1895-09-25
1896	1896-04-16	1896-09-10
1897	1897-05-07	1897-10-15
1898	1898-06-02	1898-09-29
1899	1899-04-28	1899-10-15
1900	1900-04-29	1900-10-05
1901	1901-04-27	1901-10-01
1902	1902-04-21	1902-08-30
1903	1903-05-15	1903-09-14
1904	1904-05-24	1904-09-29
1905	1905-05-04	1905-10-09
1906	1906-05-14	1906-09-18
1907	1907-06-15	1907-09-19
1908	1908-05-12	1908-09-26
1909	1909-05-05	1909-09-20
1910	1910-04-29	1910-10-14
1911	1911-05-09	1911-09-14
1912	1912-05-21	1912-10-06
1913	1913-05-01	1913-09-10
1915	1915-04-23	1915-09-14
1916	1916-05-07	1916-10-08
1922	1922-05-10	1922-10-05
1923	1923-06-02	1923-09-05
1924	1924-05-06	1924-09-21
1925	1925-04-23	1925-09-19
1926	1926-04-30	1926-10-03
1927	1927-05-21	1927-09-18
1928	1928-05-02	1928-10-11
1929	1929-05-27	1929-09-24
1930	1930-04-10	1930-10-12
1931	1931-05-16	1931-10-05
1932	1932-05-14	1932-09-19
1933	1933-05-23	1933-09-30
1934	1934-05-03	1934-09-25
1935	1935-04-26	1935-09-25
1936	1936-04-20	1936-09-16
1937	1937-05-30	1937-10-01
1938	1938-05-03	1938-10-16
1939	1939-05-23	1939-10-07
1940	1940-05-13	1940-10-05
1941	1941-04-13	1941-09-24
1942	1942-04-29	1942-09-18
1943	1943-05-05	1943-10-09
1944	1944-05-11	1944-09-19
1945	1945-06-01	1945-09-19
1946	1946-04-21	1946-10-07
1947	1947-05-15	1947-10-22
1948	1948-04-24	1948-09-19
1949	1949-05-03	1949-10-08
1950	1950-05-24	1950-10-30
1951	1951-05-01	1951-10-04
1952	1952-04-27	1952-10-01
1953	1953-05-25	1953-10-22
1954	1954-06-09	1954-10-03
1955	1955-05-03	1955-09-19
1956	1956-05-11	1956-10-16
1957	1957-05-01	1957-09-19
1958	1958-05-11	1958-09-24
1959	1959-05-02	1959-09-22
1960	1960-04-23	1960-09-08
1961	1961-05-31	1961-09-22
1962	1962-04-26	1962-10-15
1963	1963-05-08	1963-10-26
1964	1964-05-07	1964-09-20
1965	1965-05-01	1965-09-19
1966	1966-05-05	1966-09-13
1967	1967-05-25	1967-10-04
1968	1968-05-02	1968-10-15
1969	1969-05-03	1969-10-04
1970	1970-04-28	1970-09-21
1971	1971-04-12	1971-10-20
1972	1972-05-18	1972-09-20
1973	1973-06-07	1973-09-26
1974	1974-04-26	1974-09-11
1975	1975-05-18	1975-10-13
1976	1976-04-17	1976-10-03
1977	1977-04-12	1977-09-09
1978	1978-05-25	1978-09-20
1979	1979-05-08	1979-10-21
1980	1980-04-22	1980-09-22
1981	1981-04-27	1981-09-30
1982	1982-05-04	1982-10-10
1983	1983-06-08	1983-09-20
1984	1984-05-19	1984-09-25
1985	1985-04-22	1985-09-20
1986	1986-04-26	1986-09-26
1987	1987-04-21	1987-08-22
1988	1988-05-30	1988-09-23
1989	1989-04-26	1989-08-28
1990	1990-04-25	1990-09-07
1991	1991-05-14	1991-09-16
1992	1992-05-02	1992-08-26
1993	1993-05-09	1993-08-31
1994	1994-04-26	1994-10-01
1995	1995-06-08	1995-10-14
1996	1996-05-18	1996-09-06
1997	1997-06-19	1997-10-09
1998	1998-05-15	1998-09-28
1999	1999-05-29	1999-09-27
2000	2000-05-06	2000-10-02
2001	2001-05-01	2001-09-13
2002	2002-04-16	2002-10-01
2003	2003-04-15	2003-10-21
2004	2004-04-18	2004-09-15
2005	2005-06-05	2005-10-06
2006	2006-05-28	2006-10-04
2008	2008-06-03	2008-10-13
2009	2009-05-24	2009-08-16
2010	2010-05-24	2010-10-11
2011	2011-05-11	2011-10-08
2012	2012-05-19	2012-09-13
2013	2013-05-02	2013-09-20
2014	2014-05-08	2014-09-06
2015	2015-06-10	2015-09-19
2016	2016-04-18	2016-09-26
2017	2017-05-16	2017-09-27
2018	2018-05-03	2018-10-04
2019	2019-06-27	2019-10-02
2020	2020-05-25	2020-08-29
2021	2021-06-05	2021-10-02
2022	2022-05-11	2022-09-22
2023	2023-05-08	2023-10-04
2024	2024-05-22	2024-09-22
2025	2025-05-16	2025-10-05
2026	2026-05-28	2026-10-13

Every Fixed Threshold

Fixed thresholds at Ottawa 4SW
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	127	95	1901	26
35 C (95 F): Days	102	44	1934	2
40 C (104 F): Days	10	13	1936	1
90 F (32.2 C): Days	127	72	1901	10
100 F (37.8 C): Days	54	20	1936	6
110 F (43.3 C): Days	2	2	1936	2
0 C (32 F): Ice days (max	127	65	1985	30
0 C (32 F): Frost days (min	126	162	1895	77
-10 C (14 F): Days with min	126	72	1893	28
-20 C (-4 F): Days with min	113	25	1963	5
-30 C (-22 F): Days with min	7	2	1985	2
20 C (68 F): Tropical nights (min	126	41	1987	24
25 C (77 F): Days with min	42	7	1988	1
10 mm (0.39 in): Days with 10 mm or more rain	126	46	1902	38
25 mm (0.98 in): Days with 25 mm or more rain	126	15	1902	14
50 mm (1.97 in): Days with 50 mm or more rain	85	5	1981	1
100 mm (3.94 in): Days with 100 mm or more rain	7	2	1926	1
200 mm (7.87 in): Days with 200 mm or more rain	1	1	1958	1
10 cm (3.9 in): Days with 10 cm or more snowfall	86	6	1926	1
25 cm (9.8 in): Days with 25 cm or more snowfall	5	1	1901	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1893.

Download the Data

Data for Ottawa 4SW 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).

Ottawa 4SW Threshold Days by Year (USC00116526)

Key Facts for Ottawa 4SW Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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