Guernsey (St Peter Port) climate
Guernsey (St Peter Port) (Guernsey, a British Crown Dependency) has a temperate oceanic climate (Köppen Cfb). The average temperature over the year is 12 °C54 °F, and about 847 mm33 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Guernsey (St Peter Port) climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 1050 | 847 | 948 | 963.8 |
| Feb | 948 | 745 | 847 | 793.1 |
| Mar | 949 | 846 | 948 | 692.7 |
| Apr | 1151 | 949 | 1050 | 471.8 |
| May | 1355 | 1152 | 1253 | 512.0 |
| Jun | 1559 | 1356 | 1457 | 461.8 |
| Jul | 1762 | 1560 | 1661 | 471.8 |
| Aug | 1864 | 1661 | 1762 | 542.1 |
| Sep | 1763 | 1660 | 1662 | 471.8 |
| Oct | 1660 | 1457 | 1559 | 963.8 |
| Nov | 1356 | 1153 | 1254 | 1094.3 |
| Dec | 1152 | 949 | 1050 | 1064.2 |
| Year | 1864 | 745 | 1254 | 84733 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 83% | 85% | 0.9 | 8:36 |
| Feb | 83% | 82% | 1.6 | 10:03 |
| Mar | 84% | 77% | 2.9 | 11:44 |
| Apr | 85% | 68% | 4.7 | 13:40 |
| May | 87% | 68% | 5.7 | 15:19 |
| Jun | 88% | 66% | 6.0 | 16:15 |
| Jul | 88% | 63% | 5.9 | 15:52 |
| Aug | 86% | 67% | 4.9 | 14:24 |
| Sep | 83% | 67% | 3.7 | 12:31 |
| Oct | 82% | 78% | 2.1 | 10:39 |
| Nov | 82% | 85% | 1.1 | 9:00 |
| Dec | 82% | 86% | 0.7 | 8:11 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Guernsey (St Peter Port) is like
The warmest month is August, with an average high of 18 °C64 °F and a low of 16 °C61 °F. The coldest is February, when highs average 9 °C48 °F and lows 7 °C45 °F. There is a clear seasonal cycle, with 8.7 °C15.6 °F between the average temperature of the warmest and the coolest month.
Annual precipitation is moderate at about 847 mm33 in. The wettest three-month stretch is November–January, which brings 37% of the annual total. The wettest month is November (109 mm4.3 in), the driest is June (46 mm1.8 in).
Relative humidity ranges from 82% in November to 88% in July. The clearest skies (lowest average cloud amount, 63%) are typical of July. Average wind speed near the ground ranges from 16 km/h (10 mph) in June to 28 km/h (17 mph) in December. Daylight lasts from about 8.2 hours in December to 16.2 hours in June.
Best time to visit Guernsey (St Peter Port)
Based on these averages, the most comfortable months for sightseeing and outdoor activities are July–September: average highs of 17 °C62 °F to 18 °C64 °F with 47 mm1.8 in to 54 mm2.1 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 10 °C50 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Guernsey (St Peter Port)
- Winter (December–February) — highs 948 to 11 °C52 °F, lows 745 to 9 °C49 °F, about 94 mm3.7 in of precipitation a month. Pack a warm coat, layers and closed shoes and an umbrella or light rain jacket.
- Spring (March–May) — highs 949 to 13 °C55 °F, lows 846 to 11 °C52 °F, about 55 mm2.2 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Summer (June–August) — highs 1559 to 18 °C64 °F, lows 1356 to 16 °C61 °F, about 49 mm1.9 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
- Autumn (September–November) — highs 1356 to 17 °C63 °F, lows 1153 to 16 °C60 °F, about 84 mm3.3 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
How Guernsey (St Peter Port) compares
Compared with Jersey (St Helier), about 43 km to the southeast, Guernsey (St Peter Port) has practically the same average temperature and receives 10% more precipitation (847 mm33 in vs 772 mm30 in). The difference is largest in December (1.8 °C3.2 °F warmer).
Of the 66 places in the United Kingdom covered by World Climates, Guernsey (St Peter Port) is the 2nd warmest by annual mean temperature and the 27th wettest by annual precipitation. See all of them on the United Kingdom climate page.
Places in other countries with the most similar temperature and rainfall pattern (seasons shifted for the other hemisphere where needed): Brest (France, Cfb), Wellington (New Zealand, Cfb) and Hobart (Australia, Cfb).
Nearby places
- Jersey (St Helier) 43 km · 12 °C54 °F · 772 mm30 in
- Bournemouth 148 km · 12 °C53 °F · 845 mm33 in
- Plymouth 153 km · 11 °C53 °F · 1,164 mm46 in
- Exeter 157 km · 11 °C52 °F · 1,087 mm43 in
- Caen 161 km · 12 °C53 °F · 745 mm29 in
- Rennes 163 km · 12 °C53 °F · 708 mm28 in
- Southampton 180 km · 11 °C52 °F · 779 mm31 in
- Brest 186 km · 12 °C54 °F · 897 mm35 in
Frequently asked questions
What is the warmest month in Guernsey (St Peter Port)?
August is the warmest month in Guernsey (St Peter Port), with an average high of 18 °C (64 °F) and an average low of 16 °C (61 °F).
What is the coldest month in Guernsey (St Peter Port)?
February is the coldest month, with an average high of 9 °C (48 °F) and an average low of 7 °C (45 °F).
When does it rain the most in Guernsey (St Peter Port)?
November is the wettest month with about 109 mm (4.3 in) of precipitation; June is the driest with about 46 mm (1.8 in).
What is the best time to visit Guernsey (St Peter Port)?
Judging by long-term averages, the most comfortable months are July–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.