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Cornwall May Weather

Averages and records for weather in Cornwall, Ontario in the month of May.

Typical Cornwall May Weather 1991–2020
Average daily high	19.8 °C
Average daily low	8.8 °C
Average monthly precipitation	8.5 cm
Average monthly snow	0.0 cm
Daily chance of precipitation	40.5%
Daily chance of snow	0.11%

Cornwall May Weather Records 1867–2024
Highest temperature	35.6 °C	May 31, 1869
Lowest temperature	-6.1 °C	May 1, 1868
Highest daily low	25.0 °C	May 18, 2017
Lowest daily high	1.5 °C	May 1, 1978
Hottest average high temperature	23.7 °C	1998
Coldest average high temperature	14.4 °C	1967
Most daily precipitation	4.7 cm	May 8, 2000
Most monthly precipitation	17.1 cm	2000
Most daily snow	8.9 cm	May 10, 1963
Most monthly snow	8.9 cm	1963

Note: Daily averages are a moving average which includes 14 days before and after

Day	Average (°C)		Record (°C)
Day	High	Low	High	Low
May 1	16.4	5.6	29.0	-6.1
May 2	16.6	5.8	29.5	-3.9
May 3	16.8	6.0	30.0	-5.6
May 4	16.9	6.1	28.3	-4.4
May 5	17.1	6.3	28.3	-5.6
May 6	17.4	6.5	29.0	-3.9
May 7	17.6	6.7	30.0	-5.6
May 8	17.9	6.9	30.0	-5.6
May 9	18.2	7.2	30.0	-3.9
May 10	18.4	7.5	30.6	-2.8
May 11	18.7	7.7	29.0	-1.7
May 12	18.9	7.9	31.5	0.0
May 13	19.1	8.2	30.0	-2.8
May 14	19.3	8.4	31.5	-1.1
May 15	19.6	8.6	32.0	-1.1
May 16	19.8	8.8	31.5	-1.1
May 17	19.9	9.0	30.6	-4.4
May 18	20.1	9.1	32.2	0.0
May 19	20.2	9.3	31.1	0.6
May 20	20.3	9.5	32.0	-1.7
May 21	20.4	9.6	32.0	-1.1
May 22	20.5	9.8	30.6	0.6
May 23	20.6	9.9	31.7	-0.6
May 24	20.8	10.1	31.5	-4.4
May 25	21.0	10.2	32.0	-2.8
May 26	21.2	10.5	35.0	-1.1
May 27	21.4	10.6	35.0	-1.7
May 28	21.6	10.9	32.0	1.0
May 29	21.8	11.1	32.0	-0.6
May 30	22.0	11.3	32.0	-1.1
May 31	22.1	11.5	35.6	2.2

Weather Station Details

Years	Station	Coordinates
1950–2024	Cornwall	location
1867–1887	Cornwall	location