London, Ontario Temperatures: Averages by Month





The numbers here tell you how hot and cold the weather usually is in London, Ontario during each month of the year.

The average high and low temperatures are listed below monthly and annually for the city, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 10, 20 or 30 °C each month in London, scroll down farther. There are also monthly and yearly counts of days with frost and cold weather.

All the numbers are long-term historical averages based on climate data gathered from 1981 to 2010.

Average London temperatures
High °F Low °F   High °C Low °C
29 15 January -2 -9
31 17 February 0 -9
40 24 March 4 -5
54 35 April 12 2
66 45 May 19 7
75 55 June 24 13
80 59 July 26 15
78 57 August 25 14
70 50 September 21 10
57 40 October 14 4
45 31 November 7 0
34 21 December 1 -6
55 37 Year 13 3

Days of Hot Weather in London

London usually has ten days a year with temperatures in the 30s Celsius. Just once every two or three years, a day heats up above 35 degrees Celsius (95 °F). The 30-degree weather can show up here anytime from June to September, and very rarely as early as May.

Days per month in London over 10, 20 or 30 °C
  10 °C
50 °F
20 °C
68 °F
30 °C
86 °F
January 1 0 0
February 1 0 0
March 6 1 0
April 19 3 0
May 29 13 0
June 30 25 2
July 31 30 5
August 31 29 2
September 30 18 1
October 24 4 0
November 9 0 0
December 2 0 0
Year 212 122 10

When London Has Frosty Weather

London typically has 142 days a year when the minimum temperature is at 0 °C or below. The average date for the last frost in spring is April 30. Frost normally returns here on October 12. The frost-free period extends for 164 days on average between the final spring frost and the first fall frost.

Average number of days with freezing temperatures in London
  0 °C
32 °F
January 29
February 26
March 25
April 12
May 1
June 0
July 0
August 0
September 0
October 5
November 17
December 27
Year 142

How Often London Has Cold Temperatures

London's chilliest winter nights have lows in the minus-twenties °C (below -3 °F). The city averages just four nights a year, usually in January and February, when the thermometer drops that low. Temperatures down to -30 °C (-22 °F) are not normal here.

From November to April, it can remain below freezing all day long. London typically has 57 frosty days a year.

Days per month on average in London when the minimum temperature drops below -2, -10, or -20 °C
  -2 °C
28 °F
-10 °C
14 °F
-20 °C
-4 °F
January 26 13 2
February 23 11 1
March 20 5 0
April 6 0 0
May 0 0 0
June 0 0 0
July 0 0 0
August 0 0 0
September 0 0 0
October 1 0 0
November 10 1 0
December 22 8 0
Year 109 39 4
Reference

Environment Canada. Meteorological Service of Canada. Canadian Climate Normals. 1981-2010 Climate Normals & Averages.

Ontario Temperatures
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