London ON Average Temperatures 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.

The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1981 to 2010 weather.

10-year temperature averages for London, 2010 to 2019
High °F	Low °F		High °C	Low °C
29	15	January	-2	-9
31	15	February	-1	-9
41	24	March	5	-4
54	34	April	12	1
69	48	May	20	9
76	56	June	24	13
81	60	July	27	16
79	59	August	26	15
72	52	September	22	11
59	42	October	15	6
45	31	November	7	-1
35	24	December	2	-5
56	38	Year	13	3

30-year temperature averages for London, 1981 to 2010
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

London, Ontario Temperatures: Averages by Month

Days of Hot Weather in London

When London Has Frosty Weather

How Often London Has Cold Temperatures

References

More on Weather in Ontario