Ottawa September 21 Weather Records

Daily averages and all-time records for weather in Ottawa, Ontario for the date of September 21.
September 21 All-Time Records
1889–2024
Highest temperature 32.2 °C 1914
Lowest temperature -2.2 °C 1956
Lowest daily high 9.0 °C 1977
Highest daily low 21.1 °C 2002
Most precipitation 4.83 cm 1967
Most snow none -
September 21 Average Weather
1991–2020 1
Average high 19.9 °C
Average low 9.5 °C
Chance precipitation 42.7%
Chance snow 0%
Ottawa September 21 Weather by Year
Year High (°C) Low (°C) Precip. (cm) Snow (cm)
2023 25.0 5.0 0.06 0.0
2022 23.0 12.0 0.46 0.0
2021 23.0 13.5 0.22 0.0
2020 18.0 1.0 0.00 0.0
2019 27.0 10.5 0.00 0.0
2018 28.5 12.0 2.70 0.0
2017 26.0 14.0 0.00 0.0
2016 26.0 12.0 0.00 0.0
2015 20.4 5.2 0.00 0.0
2014 23.0 17.5 1.42 0.0
2013 17.5 16.5 2.16 0.0
2012 17.0 13.0 1.72 0.0
2011 25.0 8.4 0.34 0.0
2010 19.7 2.9 0.96 0.0
2009 23.7 2.3 0.04 0.0
2008 16.1 6.9 0.00 0.0
2007 26.4 11.3 0.00 0.0
2006 16.1 3.2 0.00 0.0
2005 26.0 10.1 0.06 0.0
2004 24.2 11.5 0.00 0.0
2003 19.3 11.0 0.00 0.0
2002 27.5 21.1 0.00 0.0
2001 24.4 15.1 0.57 0.0
2000 18.5 13.7 0.14 0.0
1999 14.3 6.2 0.00 0.0
1998 29.3 13.1 0.13 0.0
1997 12.8 4.7 0.00 0.0
1996 23.7 12.5 0.00 0.0
1995 17.1 12.4 0.02 0.0
1994 24.5 9.8 0.00 0.0
1993 17.5 1.4 0.00 0.0
1992 20.2 8.9 1.62 0.0
1991 13.6 0.6 0.00 0.0
1990 16.6 6.7 1.22 0.0
1989 26.4 10.6 0.00 0.0
1988 16.4 12.3 0.00 0.0
1987 13.1 10.1 0.02 0.0
1986 17.7 7.1 0.00 0.0
1985 19.2 15.4 0.00 0.0
1984 16.7 5.0 0.00 0.0
1983 26.0 14.0 3.10 0.0
1982 18.5 9.5 0.00 0.0
1981 13.5 4.0 0.04 0.0
1980 16.0 8.0 0.78 0.0
1979 18.0 12.0 0.66 0.0
1978 20.5 15.0 0.32 0.0
1977 9.0 6.5 0.18 0.0
1976 14.4 6.7 0.10 0.0
1975 17.2 10.0 0.18 0.0
1974 12.8 8.9 0.10 0.0
1973 13.3 -0.6 0.18 0.0
1972 22.2 5.6 0.00 0.0
1971 17.8 12.2 0.00 0.0
1970 23.3 10.6 0.18 0.0
1969 18.9 4.4 0.00 0.0
1968 28.3 12.8 0.00 0.0
1967 24.4 18.9 4.83 0.0
1966 13.3 6.1 1.24 0.0
1965 29.4 20.6 0.00 0.0
1964 21.1 10.0 0.00 0.0
1963 12.8 1.1 0.00 0.0
1962 10.6 1.7 0.00 0.0
1961 26.1 13.9 0.00 0.0
1960 20.6 13.3 0.00 0.0
1959 26.7 8.3 0.00 0.0
1958 16.7 7.8 1.47 0.0
1957 21.7 13.3 0.10 0.0
1956 12.2 -2.2 0.08 0.0
1955 13.9 4.4 0.00 0.0
1954 17.2 6.7 0.86 0.0
1953 14.4 11.7 0.36 0.0
1952 17.8 5.0 0.10 0.0
1951 26.7 10.6 0.00 0.0
1950 14.4 6.7 0.00 0.0
1949 15.0 6.1 0.48 0.0
1948 14.4 7.2 0.00 0.0
1947 21.7 8.3 3.18 0.0
1946 22.2 15.0 0.94 0.0
1945 16.7 5.6 0.25 0.0
1944 23.9 16.7 0.94 0.0
1943 15.6 5.0 0.00 0.0
1942 15.6 3.9 0.00 0.0
1941 27.2 6.7 0.00 0.0
1940 23.9 14.4 0.00 0.0
1939 16.7 3.3 0.00 0.0
1938 15.0 10.0 4.50 0.0
1937 18.3 6.1 0.00 0.0
1936 22.2 13.3 0.00 0.0
1935 18.9 10.6 0.15 0.0
1934 25.6 8.9 0.00 0.0
1933 17.8 11.7 0.00 0.0
1932 26.1 14.4 0.00 0.0
1931 15.6 7.8 0.00 0.0
1930 18.3 6.7 0.61 0.0
1929 13.9 -1.1 0.00 0.0
1928 18.3 14.4 0.43 0.0
1927 17.2 5.0 0.20 0.0
1926 17.8 5.6 0.00 0.0
1925 23.3 12.2 0.00 0.0
1924 22.2 13.3 0.00 0.0
1923 20.6 13.3 0.23 0.0
1922 22.2 8.9 0.00 0.0
1921 20.0 5.6 0.51 0.0
1920 17.8 -0.6 0.00 0.0
1919 28.9 14.4 0.00 0.0
1918 13.9 7.2 0.23 0.0
1917 17.8 7.2 0.00 0.0
1916 25.0 8.9 0.00 0.0
1915 16.1 12.2 0.64 0.0
1914 32.2 12.2 0.00 0.0
1913 19.4 13.9 2.31 0.0
1912 10.6 7.2 0.00 0.0
1911 18.9 7.2 0.00 0.0
1910 16.1 8.9 0.05 0.0
1909 22.8 8.3 0.00 0.0
1908 23.3 7.2 0.00 0.0
1907 23.3 12.2 0.00 0.0
1906 29.4 15.0 0.00 0.0
1905 22.8 6.1 0.00 0.0
1904 10.0 1.1 0.00 0.0
1903 23.9 5.6 0.00 0.0
1902 27.2 15.6 0.00 0.0
1901 15.0 6.1 0.00 0.0
1900 19.4 12.8 1.32 0.0
1899 17.8 10.6 0.08 0.0
1898 18.3 0.6 0.00 0.0
1897 14.4 0.6 0.00 0.0
1896 20.6 6.1 0.00 0.0
1895 32.2 16.7 0.00 0.0
1894 25.0 12.8 0.00 0.0
1893 13.9 3.3 0.00 0.0
1892 21.1 2.2 0.00 0.0
1891 27.8 12.2 0.00 0.0
1890 14.4 1.7 0.00 0.0
What's the all-time high for Ottawa on 9/21?
For the date of Sep 21, the highest temperature ever reached in Ottawa history is 32.2 °C which has happened 2 times, most recently in 1914.
Highest Temperatures in Ottawa on September 21
Rank Temperature Year
1 32.2 °C 1895
1 32.2 °C 1914
3 29.4 °C 1906
3 29.4 °C 1965
5 29.3 °C 1998
6 28.9 °C 1919
7 28.5 °C 2018
8 28.3 °C 1968
9 27.8 °C 1891
10 27.5 °C 2002
What's the all-time low for Ottawa on 9/21?
For the date of Sep 21, the lowest temperature ever reached in Ottawa history is -2.2 °C which happened in 1956.
Lowest Temperatures in Ottawa on September 21
Rank Temperature Year
1 -2.2 °C 1956
2 -1.1 °C 1929
3 -0.6 °C 1920
3 -0.6 °C 1973
5 0.6 °C 1991
5 0.6 °C 1898
5 0.6 °C 1897
8 1.0 °C 2020
9 1.1 °C 1963
9 1.1 °C 1904
Lowest High Temperatures in Ottawa on September 21
Rank Temperature Year
1 9.0 °C 1977
2 10.0 °C 1904
3 10.6 °C 1912
3 10.6 °C 1962
5 12.2 °C 1956
6 12.8 °C 1974
6 12.8 °C 1963
6 12.8 °C 1997
9 13.1 °C 1987
10 13.3 °C 1973
10 13.3 °C 1966
What's the most it has ever rained in Ottawa on 9/21?
For the date of Sep 21, the most precipitation ever recorded in Ottawa history is 4.83 cm which happened in 1967.
All-Time Most Precipitation in Ottawa on September 21
Rank Precipitation Year
1 4.83 cm 1967
2 4.50 cm 1938
3 3.18 cm 1947
4 3.10 cm 1983
5 2.70 cm 2018
6 2.31 cm 1913
7 2.16 cm 2013
8 1.72 cm 2012
9 1.62 cm 1992
10 1.47 cm 1958
Weather Station Details
Years Station Coordinates
1889–2024 Ottawa CDA location