Climate Insights for Guernsey

The climate in Guernsey is cool. The average annual temperature is 9°C and approximately 470mm of precipitation falls per year. May is the wettest month, receiving around 100mm of rainfall. Guernsey is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are February, December, January, when temperatures can drop to -6°C. Snowfall occurs from January to December, with around 182cm accumulating over the season.

Guernsey has a wide annual temperature range, spanning 38°C from the coldest to warmest months. The warmest month is July, when average highs reach 32°C and the mean temperature sits around 23°C. The coldest month is February, when overnight lows fall to -6°C and the daily average is -1°C. On average, daily temperatures fluctuate by about 13°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 9°C shift in average temperatures.

Guernsey is a relatively dry area, receiving approximately 470mm of precipitation annually, which averages out to around 39mm per month. The wettest month is May, averaging 100mm of rainfall. April and March also tend to see above-average precipitation. The driest month is January, with just 19mm. That's 81mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Snowfall is a regular feature from January to December, with around 182cm accumulating over the season. April typically sees the most snow at around 32cm.

Guernsey is relatively calm, with an average annual wind speed of 4km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is December, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 2km/h gap between the calmest and windiest months.

It is currently spring in Guernsey, which began on March 20, 2026. Guernsey is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 32°C, while the coldest stretch bottoms out in February near -6°C. Summer is next, beginning on June 21, 2026 — 7 days from now.

The best time to visit Guernsey is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 33mm per month. By contrast, February can be quite cold with temperatures dropping to -6°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Guernsey based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.