Annual mean 8°C · wettest around December · prevailing wind W
Warmest
25.6 °C
Coldest
-6.4 °C
Wettest
27%
Windiest
4.6 m/s
Prevailing
W
3.8 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Cornwall over the whole year is 8°C. July is the hottest month, with highs of about 25°C; January is the coldest, with lows of about -9°C. Cornwall has no sharply defined rainy season: the chance of rain on a given day runs from 16% in September, the driest month, to 24% in December, the wettest. Winds in Cornwall are highest in April, averaging 3.5 m/s (13 km/h), and lightest in September, at 2.0 m/s (7 km/h). The prevailing wind is from the W. The clearest skies in Cornwall come in July, when the sky is typically 35% covered; January is the cloudiest month, at 66%.
Month by month Cornwall climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
-6°C
-9°C
-11°C
22%
66%
3.2 m/s
0
0
0
February
-4°C
-8°C
-10°C
20%
58%
3.3 m/s
0
0
2
March
1°C
-4°C
-4°C
21%
52%
3.3 m/s
1
0
8
April
9°C
3°C
4°C
23%
51%
3.5 m/s
7
0
33
May
17°C
10°C
14°C
17%
44%
2.9 m/s
43
9
67
June
22°C
16°C
21°C
18%
42%
2.7 m/s
70
26
59
July
25°C
18°C
25°C
16%
35%
2.4 m/s
66
54
32
August
24°C
16°C
24°C
17%
37%
2.1 m/s
72
45
41
September
20°C
12°C
19°C
16%
41%
2.0 m/s
64
19
68
October
14°C
7°C
10°C
21%
51%
2.5 m/s
28
2
59
November
5°C
0°C
-0°C
21%
58%
3.1 m/s
4
0
15
December
-2°C
-5°C
-7°C
24%
63%
3.2 m/s
0
0
1
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Cornwall weather by season
Year round, Cornwall has days of about -6°C at their warmest in January, its coolest month, and 25°C in July, its warmest; the coolest hours of the day run from -9°C to 18°C through the year, and the average temperature over the year is 8°C around the clock. Rain is most likely around December and least likely around September. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Cornwall weather in winterDecember to February
High -4°CLow -7°CRain 22%
Winter in Cornwall has typical daily highs of about -4°C and lows of about -7°C, with a 22% chance of rain on a given day.
Cornwall weather in springMarch to May
High 9°CLow 3°CRain 20%
Spring in Cornwall has typical daily highs of about 9°C and lows of about 3°C, with a 20% chance of rain on a given day.
Cornwall weather in summerJune to August
High 24°CLow 17°CRain 17%
Summer in Cornwall has typical daily highs of about 24°C and lows of about 17°C, with a 17% chance of rain on a given day.
Cornwall weather in autumnSeptember to November
High 13°CLow 6°CRain 19%
Autumn in Cornwall has typical daily highs of about 13°C and lows of about 6°C, with a 19% chance of rain on a given day.
When is the rainy season in Cornwall?
Cornwall has no sharply defined rainy season: the chance of rain on a given day runs from 16% in September, the driest month, to 24% in December, the wettest.
What time of year is Cornwall windiest?
Winds in Cornwall are highest in April, averaging 3.5 m/s (13 km/h), and lightest in September, at 2.0 m/s (7 km/h). The prevailing wind is from the W.
What is the average temperature in Cornwall year round?
The average temperature in Cornwall over the whole year is 8°C. July is the hottest month, with highs of about 25°C; January is the coldest, with lows of about -9°C.