Sarnia Weather Records

Sarnia, Ontario weather averages and records from 1882–2024 based on data made available by the NOAA.
All-Time Recorded High
The highest temperature ever recorded in Sarnia, Ontario was 39.1 °C which occurred on June 25, 1988.
Highest Temperatures: All-Time By Year
All-Time Recorded Low
The lowest temperature ever recorded in Sarnia, Ontario was -28.9 °C which occurred on January 18, 1976.
Lowest Temperatures: All-Time By Year
Sarnia Weather by Month
Averages based on the years 1991–2020
Month Average (°C) Record (°C) Average (cm)
High ☀️ Low 🌙 High ☀️ Low 🌙 Precipitation 💧 Snow ❄️
January -0.8 -8.2 18.9 -28.9 7.0 33.7
February 0.2 -7.8 19.4 -28.0 4.3 21.1
March 5.0 -3.6 27.9 -25.6 5.3 21.1
April 11.8 1.5 31.2 -11.7 7.5 5.4
May 18.7 7.4 33.3 -3.3 8.3 0.0
June 24.0 13.1 39.1 -1.1 8.3 0.0
July 26.5 15.9 37.3 4.4 8.0 0.0
August 25.7 15.3 37.9 3.3 7.1 0.0
September 22.2 11.4 37.2 -1.6 8.1 0.0
October 15.3 5.9 32.5 -8.9 7.6 0.5
November 8.0 0.5 26.7 -15.0 6.7 6.2
December 2.2 -4.2 18.0 -25.0 6.4 25.0
Entire year 13.3 4.0 39.1 -28.9 85.3 113.2
More Sarnia Weather Records
1882–2024
Highest daily low 26.0 °C August 1, 2006
Lowest daily high -19.7 °C January 19, 1994
Greatest daily range
(Difference of high and low)
25.6 °C February 10, 1951
Greatest difference in daily high
over two conscutive days
23.2 °C Apr 15–16, 2003
Most daily precipitation 12.9 cm July 8, 2015
Most monthly precipitation 37.6 cm January 2014
Most yearly precipitation 135.4 cm 2013
Most yearly days with precipitation 215 2013
Earliest snow in season October 2 1974
Latest snow in season May 11 1907
Most daily snow 48.3 cm December 12, 1960
Most monthly snow 110.4 cm December 2000
Most yearly snow 228.8 cm 1960
Most snow in a winter 246.0 cm 1903–1904
Greatest snow accumulation 60.0 cm January 5, 2001
Earliest freeze September 23 1974
Earliest day ≥ 20 °C March 7 2000
Earliest day ≥ 25 °C March 8 2000
Earliest day ≥ 30 °C April 23 1985
Earliest day ≥ 35 °C June 19 1995
Latest freeze June 11 1972
Latest day ≥ 20 °C November 18 2016
Latest day ≥ 25 °C November 1 1950
Latest day ≥ 30 °C October 8 2007
Latest day ≥ 35 °C September 10 2013
Most days in a year < 0 °C 152 2018
Most days in a year ≥ 20 °C 147 2021
Most days in a year ≥ 25 °C 88 2007
Most days in a year ≥ 30 °C 41 1988
Most days in a year ≥ 35 °C 8 1988
Sarnia Weather Streaks
Most consecutive days...
With precipitation 37 days Dec 22, 2013 – Jan 27, 2014
Without precipitation 92 days Jul 15 – Oct 14, 2017
With snow 12 days Dec 13–24, 1985
Freezing temperatures
High temperature ≤ 0 °C
50 days Dec 21, 1976 – Feb 8, 1977
High temperature ≥ 20 °C 94 days Jun 22 – Sep 23, 2016
High temperature ≥ 25 °C 21 days Aug 1–21, 2010
High temperature ≥ 30 °C 11 days Aug 25 – Sep 4, 1953
High temperature ≥ 35 °C 4 days Jul 6–9, 1988
Plant Hardiness Zone
6A
Sarnia is in plant hardiness zone 6A
based on average yearly minimum temperature from 1991–2020
Sarnia Weather by Year
More Sarnia Weather
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Weather Station Details
Years Station Coordinates
2009–2024 Sarnia location
1968–2008 Sarnia Airport location
1961–1967 Sarnia Waterworks location
1882–1961 Sarnia location