Ottawa Weather Records

Ottawa, Ontario weather averages and records from 1889–2024 based on data made available by the NOAA.
All-Time Recorded High
The highest temperature ever recorded in Ottawa, Ontario was 37.8 °C which occurred on August 14, 1944.
Highest Temperatures: All-Time By Year
All-Time Recorded Low
The lowest temperature ever recorded in Ottawa, Ontario was -38.9 °C which occurred on December 29, 1933.
Lowest Temperatures: All-Time By Year
Ottawa Weather by Month
Averages based on the years 1991–2020
Month Average (°C) Record (°C) Average (cm)
High ☀️ Low 🌙 High ☀️ Low 🌙 Precipitation 💧 Snow ❄️
January -5.2 -13.7 12.0 -37.8 6.5 43.8
February -3.5 -12.8 12.5 -38.3 5.1 39.9
March 2.6 -6.7 26.7 -36.7 6.1 30.6
April 11.3 1.3 31.2 -20.6 8.0 7.7
May 19.6 8.3 35.2 -7.2 8.0 0.0
June 24.4 13.6 36.7 0.0 9.5 0.0
July 26.8 16.0 37.8 3.3 9.2 0.0
August 25.7 14.8 37.8 1.7 8.7 0.0
September 21.3 10.5 36.7 -4.4 8.7 0.0
October 13.4 4.5 31.0 -12.8 8.9 2.0
November 5.9 -1.5 24.0 -23.9 7.0 16.2
December -1.6 -8.5 17.2 -38.9 7.2 42.4
Entire year 11.8 2.2 37.8 -38.9 92.7 181.8
More Ottawa Weather Records
1889–2024
Highest daily low 24.8 °C August 9, 2001
Lowest daily high -31.7 °C December 29, 1933
Greatest daily range
(Difference of high and low)
35.6 °C March 4, 1950
Greatest difference in daily high
over two conscutive days
26.7 °C Jan 28–29, 1934
Most daily precipitation 10.9 cm September 9, 2004
Most monthly precipitation 25.0 cm July 1899
Most yearly precipitation 118.3 cm 2017
Most yearly days with precipitation 187 1980
Earliest snow in season October 8 1979
Latest snow in season May 26 1994
Most daily snow 55.9 cm January 29, 1894
Most monthly snow 137.8 cm February 1971
Most yearly snow 356.9 cm 1971
Most snow in a winter 387.8 cm 1970–1971
Greatest snow accumulation 97.0 cm February 25, 1971
Earliest freeze September 13 1946
Earliest day ≥ 20 °C March 18 2012
Earliest day ≥ 25 °C March 20 2012
Earliest day ≥ 30 °C April 13 2023
Earliest day ≥ 35 °C May 21 1921
Latest freeze May 29 1907
Latest day ≥ 20 °C November 12 2012
Latest day ≥ 25 °C October 24 1963
Latest day ≥ 30 °C October 4 2023
Latest day ≥ 35 °C September 11 1931
Most days in a year < 0 °C 184 1907
Most days in a year ≥ 20 °C 146 2023
Most days in a year ≥ 25 °C 97 1959
Most days in a year ≥ 30 °C 42 1955
Most days in a year ≥ 35 °C 10 1916
Ottawa Weather Streaks
Most consecutive days...
With precipitation 16 days Sep 23 – Oct 8, 1991
Without precipitation 25 days Mar 19 – Apr 12, 1941
With snow 11 days Dec 7–17, 1978
Freezing temperatures
High temperature ≤ 0 °C
61 days Dec 17, 1944 – Feb 15, 1945
High temperature ≥ 20 °C 104 days Jun 2 – Sep 13, 1921
High temperature ≥ 25 °C 45 days Jun 17 – Jul 31, 1921
High temperature ≥ 30 °C 12 days Jul 29 – Aug 9, 1911
High temperature ≥ 35 °C 4 days Aug 19–22, 1916
Plant Hardiness Zone
5A
Ottawa is in plant hardiness zone 5A
based on average yearly minimum temperature from 1991–2020
Ottawa Weather by Year
More Ottawa Weather
Compare Ottawa to:
Weather Station Details
Years Station Coordinates
1889–2024 Ottawa CDA location