Guernsey weather by month
Average temperatures and rainfall across Guernsey, based on 30 years of climate data.
The average temperature in Guernsey is around 12° across the year, though it swings month to month and from region to region. The figures below show the monthly pattern for Saint Peter Port.
- Hottest
- Aug
- 17°
- Coldest
- Feb
- 7°
- Wettest
- Nov
- 121 mm
- Driest
- Jul
- 36 mm
- Annual avg
- 12°
- year-round
- Rain / yr
- 860 mm
- 140 wet days
- Largest city
- Saint Peter Port
- 16k people
- Cities
- 1
- with climate data
Monthly climate (Saint Peter Port)
Average highs, lows and rainfall through the year for Saint Peter Port, Guernsey's largest city.
| Month | High / Low | Rainfall | Wet days |
|---|---|---|---|
| Jan | 10° / 8° | 98 mm | 15.7 |
| Feb | 9° / 7° | 74 mm | 13.3 |
| Mar | 10° / 8° | 58 mm | 11.5 |
| Apr | 11° / 9° | 50 mm | 9.7 |
| May | 13° / 11° | 45 mm | 7.9 |
| Jun | 15° / 13° | 42 mm | 7.5 |
| Jul | 17° / 15° | 36 mm | 6.9 |
| Aug | 17° / 16° | 50 mm | 8.6 |
| Sep | 17° / 15° | 57 mm | 9.4 |
| Oct | 15° / 14° | 107 mm | 15 |
| Nov | 13° / 11° | 121 mm | 17.7 |
| Dec | 11° / 9° | 121 mm | 17 |
Climate in Saint Peter Port
Full Saint Peter Port forecastSaint Peter Port is the largest city in Guernsey; its cloud cover, humidity, wind and sunshine are typical of the surrounding region.
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast through the year.
In Saint Peter Port, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around March 24 and lasts for 6.3 months, ending around September 30. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 57% of the time on average.
The cloudier part of the year begins around October 1 and lasts for 5.7 months, ending around March 23. The cloudiest month is December, when it is overcast or mostly cloudy 75% of the time.
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Across the year, average wind speed in Saint Peter Port is typically breezy, near 28 km/h, and varies a lot with the seasons.
The windier part of the year lasts 5.8 months, from around Oct 1 to Mar 25. The windiest month is January, averaging about 34 km/h (windy).
The calmer part of the year runs from around Mar 26 to Sep 30, with July the calmest month at about 22 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 34 | 32 | 29 | 26 | 24 | 22 | 22 | 22 | 26 | 30 | 33 | 35 |
| Feels | windy | windy | windy | breezy | breezy | breezy | breezy | breezy | breezy | windy | windy | windy |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 34 | windy |
| Feb | 32 | windy |
| Mar | 29 | windy |
| Apr | 26 | breezy |
| May | 24 | breezy |
| Jun | 22 | breezy |
| Jul | 22 | breezy |
| Aug | 22 | breezy |
| Sep | 26 | breezy |
| Oct | 30 | windy |
| Nov | 33 | windy |
| Dec | 35 | windy |
Best time to visit Guernsey
A 0–10 score combining daytime comfort, chance of rain and cloud cover — the sweet spot runs late June to late September.
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Saint Peter Port receives about 3.5 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.8 and 6.4 kWh/m².
The brighter stretch of the year lasts 5.9 months, from around Mar 23 to Sep 19. The brightest month is June, averaging about 6.3 kWh/m² (intense).
The dimmest month is December, down near 0.8 kWh/m² — roughly 87% less than the June peak.
Where is Guernsey?
Guernsey sits around 49.5°N, 2.5°W. The marker shows Saint Peter Port, its largest city, among 1 city with climate data here.
Guernsey travel facts
- Power plugs
- Type G
- 230 V · 50 Hz
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.