The climate of the Isles of Scilly is
oceanic, with quite mild, rainy winters and mild, relatively rainy summers.
The islands are located south-west of the south-western tip of Great Britain (Cornwall). The main islands are St. Mary's, Tresco, St. Martin's, St. Agnes and Bryher.
With an average annual temperature close to 12 °C (53 °F), the Isles of Scilly are the mildest place in Great Britain, especially thanks to the particularly high winter temperatures. The average of 8 °C (46 °F) in January exceeds that of Plymouth (in Devon), where it is 6.5 °C (44 °F), and that of the south coast of England (see Eastbourne, Brighton) where it is around 5.5 °C (42 °F).
Winter is mild enough, although the sky is often cloudy, the humidity is high and there are periods when the wind blows moderate or strong. The rains are frequent.
The islands are quite sheltered from the cold waves that can sometimes affect Great Britain, in fact, snow is rare, and frosts are even more so. On the coldest nights of the year, the temperature typically drops to around 0 °C (32 °F). In March 2018, it dropped to -2 °C (28.5 °F). The only real wave of frost in recent decades was that of January 1987, when the temperature dropped to -7 °C (19.5 °F) and 23 cm (9 in) of snow fell.
In
summer, temperatures are generally mild or cool. It can also rain, albeit a little less often than in winter.
Hot days are very rare. Generally, the temperature reaches 22/24 °C (72/75 °F) on the warmest days of the year. The highest record is just 28 °C (82 °F).
Best Time
The best time to visit the Isles of Scilly is the summer, or more generally
from mid-May to mid-September: temperatures are generally good for outdoors activities, although it's better to bring an umbrella, and a sweatshirt or sweater for the evening or for cool days.
Scilly - Climate data
The
average temperature of the coldest month (February) is of 8.1 °C (46.6 °F), that of the warmest month (August) is of 17 °C (62.6 °F). Here are the average temperatures.
Scilly - Average temperatures (1991-2020) Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
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January | 6.4 | 9.9 | 8.2 | 44 | 50 | 46.7 |
---|
February | 6.3 | 10 | 8.1 | 43 | 50 | 46.6 |
---|
March | 6.7 | 10.9 | 8.8 | 44 | 52 | 47.8 |
---|
April | 7.5 | 12.6 | 10 | 46 | 55 | 50.1 |
---|
May | 9.5 | 14.7 | 12.1 | 49 | 58 | 53.8 |
---|
June | 12 | 17.3 | 14.6 | 54 | 63 | 58.3 |
---|
July | 13.8 | 19.3 | 16.6 | 57 | 67 | 61.8 |
---|
August | 14.3 | 19.7 | 17 | 58 | 67 | 62.6 |
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September | 13.1 | 18.3 | 15.7 | 56 | 65 | 60.3 |
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October | 10.8 | 15 | 12.9 | 51 | 59 | 55.3 |
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November | 8.7 | 12.2 | 10.4 | 48 | 54 | 50.8 |
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December | 7.1 | 10.6 | 8.9 | 45 | 51 | 48 |
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Year | 9.7 | 14.2 | 11.95 | 49.5 | 57.6 | 53.5 |
---|
Precipitation amounts to 880 millimeters (34.6 inches) per year: so, it is at an intermediate level. It ranges from 50 mm (2 in) in the driest months (April, May, June) to 100 mm (3.9 in) in the wettest ones (November, December) Here is the average precipitation.
Scilly - Average precipitationMonth | Millimeters | Inches | Days |
---|
January | 95 | 3.7 | 15 |
---|
February | 75 | 3 | 13 |
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March | 55 | 2.2 | 12 |
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April | 50 | 2 | 10 |
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May | 50 | 2 | 9 |
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June | 50 | 2 | 9 |
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July | 70 | 2.8 | 9 |
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August | 75 | 3 | 10 |
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September | 70 | 2.8 | 10 |
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October | 90 | 3.5 | 14 |
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November | 100 | 3.9 | 16 |
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December | 100 | 3.9 | 16 |
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Year | 880 | 34.6 | 142 |
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The
sea temperature ranges from 10 °C (50 °F) in March to 17 °C (63 °F) in August, September. Here are the average sea temperatures.
Scilly - Sea temperatureMonth | Celsius (°C) | Fahrenheit (°F) |
---|
January | 10.5 | 51 | February | 10.5 | 51 | March | 10 | 50 | April | 11 | 51 | May | 12 | 54 | June | 14 | 58 | July | 16.5 | 62 | August | 17 | 63 | September | 17 | 62 | October | 15 | 59 | November | 13.5 | 56 | December | 12 | 53 | Year | 13.3 | 55.9 |
There are on average around 1710
sunshine hours per year. Here are the average hours of sunshine per day.
Scilly - Sunshine hoursMonth | Average | Total |
---|
January | 2 | 60 | February | 3 | 85 | March | 4 | 130 | April | 6.5 | 195 | May | 7 | 220 | June | 7 | 210 | July | 6.5 | 205 | August | 6.5 | 195 | September | 5.5 | 165 | October | 4 | 115 | November | 2.5 | 70 | December | 1.5 | 50 | Year | 4.7 | 1710 |