Ottawa September 18 Weather Records

Daily averages and all-time records for weather in Ottawa, Ontario for the date of September 18.
September 18 All-Time Records
1889–2024
Highest temperature 30.6 °C 1955
Lowest temperature -0.6 °C 1950
Lowest daily high 11.1 °C 1956
Highest daily low 20.0 °C 1948
Most precipitation 6.05 cm 1945
Most snow none -
September 18 Average Weather
1991–2020 1
Average high 20.7 °C
Average low 10.1 °C
Chance precipitation 41.1%
Chance snow 0%
Ottawa September 18 Weather by Year
Year High (°C) Low (°C) Precip. (cm) Snow (cm)
2023 30.0 14.0 4.80 0.0
2022 21.5 12.5 1.74 0.0
2021 22.0 17.0 0.00 0.0
2020 14.0 3.0 0.00 0.0
2019 21.0 8.0 0.00 0.0
2018 23.5 16.0 0.00 0.0
2017 28.0 13.0 0.00 0.0
2016 26.5 17.0 0.00 0.0
2015 28.7 15.3 0.00 0.0
2014 11.5 4.9 0.00 0.0
2013 22.0 4.0 0.00 0.0
2012 18.9 14.4 2.73 0.0
2011 19.6 2.6 0.00 0.0
2010 19.5 4.0 0.00 0.0
2009 17.2 10.9 0.00 0.0
2008 13.1 6.1 0.00 0.0
2007 22.5 5.0 0.00 0.0
2006 26.8 13.6 1.93 0.0
2005 24.0 15.0 0.00 0.0
2004 16.0 7.5 0.00 0.0
2003 24.5 8.5 0.08 0.0
2002 23.3 9.6 0.00 0.0
2001 19.7 13.8 0.00 0.0
2000 21.1 7.1 0.00 0.0
1999 22.1 8.2 0.00 0.0
1998 23.0 8.3 0.00 0.0
1997 23.9 12.6 0.02 0.0
1996 22.6 11.2 0.00 0.0
1995 15.1 4.3 0.00 0.0
1994 16.4 7.9 0.05 0.0
1993 17.6 12.9 0.00 0.0
1992 26.8 17.9 2.12 0.0
1991 23.3 9.0 0.02 0.0
1990 15.1 2.8 0.00 0.0
1989 24.0 7.8 0.00 0.0
1988 22.3 13.0 0.00 0.0
1987 18.3 8.0 0.00 0.0
1986 17.5 5.3 0.00 0.0
1985 27.8 6.9 0.00 0.0
1984 21.4 6.0 0.00 0.0
1983 19.5 13.0 0.00 0.0
1982 18.0 9.0 0.12 0.0
1981 16.5 10.5 0.00 0.0
1980 14.5 4.0 0.00 0.0
1979 24.0 12.5 1.20 0.0
1978 13.0 3.5 0.16 0.0
1977 20.5 15.5 0.00 0.0
1976 20.0 17.8 1.42 0.0
1975 17.8 10.6 0.99 0.0
1974 14.4 2.8 0.00 0.0
1973 15.6 6.7 0.00 0.0
1972 19.4 11.1 0.58 0.0
1971 20.0 8.9 0.00 0.0
1970 16.7 10.6 0.00 0.0
1969 13.3 4.4 0.00 0.0
1968 26.1 15.0 0.00 0.0
1967 27.2 15.0 0.00 0.0
1966 23.9 7.2 0.00 0.0
1965 18.3 14.4 1.83 0.0
1964 18.9 5.0 0.00 0.0
1963 25.6 5.6 0.03 0.0
1962 16.1 9.4 0.28 0.0
1961 22.8 1.7 0.00 0.0
1960 17.2 11.1 0.00 0.0
1959 12.8 3.3 0.00 0.0
1958 12.8 11.1 0.46 0.0
1957 22.2 6.7 0.00 0.0
1956 11.1 5.6 0.33 0.0
1955 30.6 15.0 0.00 0.0
1954 15.6 10.0 0.13 0.0
1953 16.7 0.0 0.00 0.0
1952 22.2 7.8 1.30 0.0
1951 19.4 3.9 0.00 0.0
1950 18.3 -0.6 0.46 0.0
1949 19.4 11.7 0.84 0.0
1948 23.3 20.0 0.08 0.0
1947 24.4 8.3 1.12 0.0
1946 30.0 14.4 0.00 0.0
1945 11.7 5.6 6.05 0.0
1944 25.6 12.8 0.00 0.0
1943 16.1 -0.6 0.00 0.0
1942 30.0 15.6 0.00 0.0
1941 18.3 10.0 0.00 0.0
1940 23.9 10.6 0.08 0.0
1939 16.7 1.7 0.00 0.0
1938 17.8 6.7 0.05 0.0
1937 16.7 1.1 0.28 0.0
1936 19.4 5.6 0.00 0.0
1935 26.1 8.9 0.00 0.0
1934 13.3 10.0 0.00 0.0
1933 21.1 13.9 0.15 0.0
1932 15.6 7.2 0.36 0.0
1931 20.6 9.4 0.00 0.0
1930 18.3 11.1 0.00 0.0
1929 11.1 6.7 0.10 0.0
1928 13.3 6.1 0.00 0.0
1927 23.3 10.0 0.05 0.0
1926 20.0 11.1 0.00 0.0
1925 25.0 12.2 2.13 0.0
1924 21.1 8.9 0.00 0.0
1923 19.4 3.9 0.00 0.0
1922 17.2 1.1 0.00 0.0
1921 19.4 12.2 0.00 0.0
1920 21.1 12.2 0.00 0.0
1919 21.1 2.2 0.00 0.0
1918 15.0 5.0 0.38 0.0
1917 26.7 8.3 0.00 0.0
1916 14.4 4.4 0.00 0.0
1915 24.4 10.6 0.00 0.0
1914 25.6 11.1 0.00 0.0
1913 18.9 10.0 0.81 0.0
1912 18.3 7.8 0.25 0.0
1911 23.9 9.4 0.00 0.0
1910 15.6 11.1 0.05 0.0
1909 16.7 5.6 0.00 0.0
1908 23.9 8.3 0.10 0.0
1907 17.2 5.6 0.00 0.0
1906 28.3 15.6 0.10 0.0
1905 22.2 16.1 2.49 0.0
1904 21.1 10.6 1.27 0.0
1903 13.3 4.4 0.15 0.0
1902 22.8 7.2 0.00 0.0
1901 15.6 6.7 0.00 0.0
1900 13.3 6.1 0.36 0.0
1899 23.9 14.4 0.00 0.0
1898 25.0 11.1 0.97 0.0
1897 15.6 2.2 0.00 0.0
1896 18.9 7.8 0.00 0.0
1895 12.8 5.0 0.00 0.0
1894 24.4 12.8 0.00 0.0
1893 13.3 3.9 0.05 0.0
1892 24.4 8.3 0.00 0.0
1891 30.0 17.8 1.22 0.0
1890 21.7 6.7 0.00 0.0
What's the all-time high for Ottawa on 9/18?
For the date of Sep 18, the highest temperature ever reached in Ottawa history is 30.6 °C which happened in 1955.
Highest Temperatures in Ottawa on September 18
Rank Temperature Year
1 30.6 °C 1955
2 30.0 °C 1942
2 30.0 °C 2023
2 30.0 °C 1891
2 30.0 °C 1946
6 28.7 °C 2015
7 28.3 °C 1906
8 28.0 °C 2017
9 27.8 °C 1985
10 27.2 °C 1967
What's the all-time low for Ottawa on 9/18?
For the date of Sep 18, the lowest temperature ever reached in Ottawa history is -0.6 °C which has happened 2 times, most recently in 1950.
Lowest Temperatures in Ottawa on September 18
Rank Temperature Year
1 -0.6 °C 1943
1 -0.6 °C 1950
3 0.0 °C 1953
4 1.1 °C 1937
4 1.1 °C 1922
6 1.7 °C 1961
6 1.7 °C 1939
8 2.2 °C 1897
8 2.2 °C 1919
10 2.6 °C 2011
Lowest High Temperatures in Ottawa on September 18
Rank Temperature Year
1 11.1 °C 1956
1 11.1 °C 1929
3 11.5 °C 2014
4 11.7 °C 1945
5 12.8 °C 1959
5 12.8 °C 1895
5 12.8 °C 1958
8 13.0 °C 1978
9 13.1 °C 2008
10 13.3 °C 1893
10 13.3 °C 1900
10 13.3 °C 1934
10 13.3 °C 1969
10 13.3 °C 1903
10 13.3 °C 1928
What's the most it has ever rained in Ottawa on 9/18?
For the date of Sep 18, the most precipitation ever recorded in Ottawa history is 6.05 cm which happened in 1945.
All-Time Most Precipitation in Ottawa on September 18
Rank Precipitation Year
1 6.05 cm 1945
2 4.80 cm 2023
3 2.73 cm 2012
4 2.49 cm 1905
5 2.13 cm 1925
6 2.12 cm 1992
7 1.93 cm 2006
8 1.83 cm 1965
9 1.74 cm 2022
10 1.42 cm 1976
Weather Station Details
Years Station Coordinates
1889–2024 Ottawa CDA location