Ottawa Threshold Days by Year

6 fixed thresholds counted per year at Ottawa (USC00336342): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Ottawa Thresholds

Ottawa: days with 10 mm (0.39 in) or more of precipitation in 53 years, most in 2011 with 50.
Ottawa: days with 25 mm (0.98 in) or more of precipitation in 53 years, most in 1950 with 18.
Ottawa: days with 50 mm (1.97 in) or more of precipitation in 34 years, most in 2013 with 4.
Ottawa: days with 10 cm (3.9 in) or more of snowfall in 21 years, most in 1977 with 4.
6 fixed thresholds have at least one qualifying day at Ottawa.

Days with 10 mm (0.39 in) or more of precipitation

53 years with a qualifying day

Days per year at Ottawa with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 50 in 2011.

Days with 10 mm (0.39 in) or more of precipitation per year at Ottawa
Year	Days	Decade average
1950	37	37
1968	31	30.5
1969	30	30.5
1970	31	30.8
1971	30	30.8
1972	39	30.8
1973	29	30.8
1974	19	30.8
1975	33	30.8
1976	25	30.8
1977	40	30.8
1978	27	30.8
1979	35	30.8
1980	31	29.8
1981	27	29.8
1982	29	29.8
1983	36	29.8
1984	28	29.8
1985	37	29.8
1986	43	29.8
1987	27	29.8
1988	22	29.8
1989	18	29.8
1990	38	33
1998	31	33
1999	30	33
2000	34	30.7
2001	33	30.7
2002	31	30.7
2003	36	30.7
2004	33	30.7
2005	29	30.7
2006	23	30.7
2007	27	30.7
2008	33	30.7
2009	28	30.7
2010	32	35.3
2011	50	35.3
2012	28	35.3
2013	26	35.3
2014	31	35.3
2015	38	35.3
2016	33	35.3
2017	36	35.3
2018	38	35.3
2019	41	35.3
2020	28	31.4
2021	37	31.4
2022	34	31.4
2023	30	31.4
2024	34	31.4
2025	29	31.4
2026	28	31.4

For each year, a bar from the first to the last day at Ottawa meeting 10 mm (0.39 in).

First to last qualifying date each year at Ottawa
Year	First date	Last date
1950	1950-01-02	1950-12-07
1968	1968-01-28	1968-12-28
1969	1969-01-18	1969-12-31
1970	1970-02-02	1970-12-12
1971	1971-01-04	1971-12-30
1972	1972-03-02	1972-12-14
1973	1973-01-04	1973-12-31
1974	1974-01-19	1974-11-05
1975	1975-01-08	1975-12-27
1976	1976-01-14	1976-10-20
1977	1977-02-27	1977-12-25
1978	1978-01-26	1978-12-03
1979	1979-01-02	1979-12-24
1980	1980-01-11	1980-12-30
1981	1981-02-02	1981-12-23
1982	1982-01-04	1982-12-26
1983	1983-03-09	1983-12-22
1984	1984-02-25	1984-12-30
1985	1985-02-06	1985-12-12
1986	1986-01-19	1986-12-02
1987	1987-01-20	1987-12-20
1988	1988-02-03	1988-12-28
1989	1989-01-25	1989-12-31
1990	1990-01-04	1990-12-30
1998	1998-01-03	1998-12-22
1999	1999-01-03	1999-12-14
2000	2000-01-04	2000-12-17
2001	2001-02-11	2001-12-17
2002	2002-01-30	2002-12-25
2003	2003-01-01	2003-12-30
2004	2004-01-04	2004-12-23
2005	2005-01-04	2005-12-27
2006	2006-01-03	2006-12-27
2007	2007-01-01	2007-12-30
2008	2008-02-04	2008-12-24
2009	2009-01-14	2009-12-08
2010	2010-02-05	2010-11-29
2011	2011-01-01	2011-12-20
2012	2012-01-16	2012-12-20
2013	2013-01-10	2013-12-21
2014	2014-01-05	2014-12-05
2015	2015-01-03	2015-12-28
2016	2016-01-09	2016-12-11
2017	2017-01-02	2017-11-18
2018	2018-02-15	2018-12-31
2019	2019-01-22	2019-12-29
2020	2020-01-09	2020-11-30
2021	2021-01-01	2021-12-28
2022	2022-02-02	2022-12-30
2023	2023-01-01	2023-12-22
2024	2024-01-09	2024-12-31
2025	2025-02-14	2025-12-28
2026	2026-01-25	2026-08-16

Every Fixed Threshold

Fixed thresholds at Ottawa
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
10 mm (0.39 in): Days with 10 mm or more rain	53	50	2011	28
25 mm (0.98 in): Days with 25 mm or more rain	53	18	1950	8
50 mm (1.97 in): Days with 50 mm or more rain	34	4	2013	1
100 mm (3.94 in): Days with 100 mm or more rain	3	1	1981	1
200 mm (7.87 in): Days with 200 mm or more rain	1	1	2007	1
10 cm (3.9 in): Days with 10 cm or more snowfall	21	4	1977	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1950.

Download the Data

Data for Ottawa 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 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Ottawa Threshold Days by Year

Key Facts for Ottawa Thresholds

Days with 10 mm (0.39 in) or more of precipitation

Every Fixed Threshold

Download the Data

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