Cornwall's Weather & Climate

Cornwall for the most part is surrounded by sea, and it is hardly surprising that the sea exerts a marked influence on the weather and climate of the county.

On the eastern edge of the Gulf Stream the greatest effect is felt in winter, when temperatures are generally higher than would be normally expected at such latitudes; the mean January temperature in Cornwall is similar to such Mediterranean resorts as Benidorm, Nice, Naples and Corfu! In summer, however, the sea does moderate the highest temperatures.

During the winter the temperature rarely falls below freezing (0C) and in summer, although the mean maximum is around 19C, the daytime maximum often reaches 21C and occasionally 30C.

Rain falls the year round, with a distinct maximum during winter, mainly from the regular procession of weather fronts that move east across the Atlantic and the U.K.

In summer these fronts are generally less frequent, taking a more northerly track and are much weaker, so the rain is often derived from thunderstorms generated over France and drifting north across southern England, usually during the evening and overnight.

Cornwall can expect well over 1500 hours of sunshine annually and, whilst May is usually the sunniest month, May to July average around 7 hours of sunshine a day.

From a sailor's and windsurfer's viewpoint, the exposed coastal waters around the county yield a mean wind speed force 4 - 5 in winter and 3 - 4 in summer. Gales can be expected around 10 days per month from December to February, but on average less than 1 day per month from May to August.

The sea temperature varies from 9 - 10C in February to 16 - 17C in August.

Newquay (Atlantic Coast)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hours of sun 59.6 83 131.2 189.9 219.7 216.5 204.1 193.5 157.6 11.3 73.1 55.2
Max. Temp Celcius 8.2 8 8 1.6 14 17 18.3 18.5 17.1 14.4 0.9 9.3
Min. Temp Celcius 3.2 2.8 2.8 5.4 7.9 10.7 12.5 12.7 11.2 9.1 5.9 4.5
Sea Temp. 8 9 9 10 11 12 15 16 14 13 13 8
Rainfall (mm) 113 91 80 52 61 56 64 73 81 92 111 116
Bude (Atlantic Coast)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hours of sun 56.4 78.1 127.4 179.1 209.6 198.1 188.8 180.3 148.1 107.4 66.8 15.1
Max. Temp Celcius 8.5 8.3 10 12 14.8 17.4 18.7 18.9 17.6 15.1 11.4 9.7
Min. Temp Celcius 3.1 2.8 3.8 5.1 7.7 10.5 12.3 12.5 10.9 8.7 5.7 4.4
Sea Temp. 9 8 9 10 11 13 15 15 14 10 12 9
Rainfall (mm) 93 67 62 49 53 51 66 75 79 83 103 95
St Ives (Far West)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hours of sun 55.7 79.7 124.7 181.3 215.6 212 200.4 187.3 151.9 107.6 68.5 50.6
Max. Temp Celcius 8.5 8.2 9.7 11.5 14.2 16.9 18.4 18.6 17.1 14.5 11.1 9.6
Min. Temp Celcius 4 3.6 4.6 5.8 8.1 10.6 12.4 12.7 11.5 9.6 6.5 5.3
Sea Temp. 8 9 10 10 11 12 14 16 14 13 12 9
Rainfall (mm) 129 106 88 55 66 61 66 75 86 100 119 132
Fowey (Riviera Coast)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hours of sun 59 64 110 179 189 166 179 184 123 90 97 42
Max. Temp Celcius 8.7 8.6 10.1 12.3 14.9 17.8 19.5 19.4 17.7 15.1 11.5 9.9
Min. Temp Celcius 3.5 3.2 4.2 5.6 8 10.7 12.4 12.6 11.1 9.1 5.9 47
Sea Temp. 8 9 10 11 11 13 14 16 15 14 13 10
Rainfall (mm) 140 102 122 55 69 70 61 66 88 126 117 157
Falmouth (Riveria Coast)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hours of sun 58 78 120.2 180.9 216.2 215.3 209.3 192.3 152.4 104.6 71.8 51.9
Max. Temp Celcius 8.8 8.5 9.8 11.9 14.5 17.4 19.1 19 17.2 14.6 11.4 9.9
Min. Temp Celcius 3.9 3.5 4.5 5.8 8.1 10.8 12.5 12.8 11.3 5.9 6.3 5.1
Sea Temp. 8 9 9 10 11 12 15 16 14 13 13 8
Rainfall (mm) 130 103 92 61 64 59 65 79 91 99 127 132

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