St Peter Port climate — normals and trends
St Peter Port (Guernsey) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 11.9 °C and it receives 825 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (16.5 °C on average) and the coldest is February (7.8 °C). Rainfall peaks in November.
St Peter Port averages 0 frost days, 0 hot days (≥ 30 °C) and 143 rainy days per year.
St Peter Port has warmed by +1.2 °C between 1940 and 2025, or +0.14 °C per decade. This trend is statistically significant.
The hottest day of the period reached 23.9 °C (on 18 July 2022) and the coldest -4.4 °C (on 13 January 1987).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
St Peter PortSt Peter Port
- coords
- 49.46°, -2.54°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
11.9°C
Average daily high
12.8°C
Average daily low
11.1°C
Annual rainfall
825mm
Sunshine / day
8.9h
Mean relative humidity
81%
Average peak wind
36.1km/h
Seasonal range
8.7°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
143 d/yr
Annual snowfall
4.9 cm
Average feels-like high
9.4 °C
Average feels-like low
6.2 °C
Average peak gust
48.4 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
12.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.2 °C
since 1940
+0.1 °C per decade · r² = 0.36 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
23.9 °C
18 July 2022
Coldest day
-4.4 °C
13 January 1987
Wettest day
52 mm
8 October 1997
Windiest day
102.8 km/h
16 October 1987
Strongest gust
144.0 km/h
16 October 1987
Hottest feels-like
24.3 °C
10 August 2003
Coldest feels-like
-14.1 °C
12 January 1987
Snowiest day
12.5 cm
11 March 2013
Sunniest day
15.8 h
19 June 2025
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 9.5 °C | +0.1 °C | 157 mm | +62 mm |
| Feb | 9.5 °C | +0.7 °C | 66 mm | -11 mm |
| Mar | 10.3 °C | +0.9 °C | 27 mm | -34 mm |
| Apr | 12.0 °C | +1.7 °C | 46 mm | +0 mm |
| May | 13.7 °C | +1.5 °C | 16 mm | -29 mm |
| Jun | 16.4 °C | +2.0 °C | 40 mm | +3 mm |
| Jul | 17.8 °C | +1.5 °C | 28 mm | -8 mm |
| Aug | 18.6 °C | +1.5 °C | 19 mm | -25 mm |
| Sep | 17.4 °C | +0.6 °C | 83 mm | +23 mm |
| Oct | 15.8 °C | +0.6 °C | 113 mm | +20 mm |
| Nov | 13.9 °C | +1.4 °C | 101 mm | -19 mm |
| Dec | 11.6 °C | +1.0 °C | 125 mm | +13 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of St Peter Port?
St Peter Port has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 11.9 °C and it receives 825 mm of precipitation per year.
What is the hottest day ever recorded in St Peter Port?
The hottest day measured in St Peter Port between 1940 and 2025 was 18 July 2022, reaching 23.9 °C.
What is the coldest day in St Peter Port?
The coldest day measured in St Peter Port between 1940 and 2025 was 13 January 1987, at -4.4 °C.
Does it snow in St Peter Port?
Yes. St Peter Port gets on average 4.9 cm of snow per year and has around 0 frost days.
Has the climate of St Peter Port warmed?
Yes: St Peter Port warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in St Peter Port?
The wettest day measured in St Peter Port between 1940 and 2025 was 8 October 1997, with 52 mm of rain in 24 hours.
What was the windiest day in St Peter Port?
The windiest day measured in St Peter Port between 1940 and 2025 was 16 October 1987, with winds reaching 102.8 km/h.
What is the warmest month in St Peter Port?
The warmest month in St Peter Port is August (16.5 °C on average); the coldest is February (7.8 °C).
How much does it rain in St Peter Port?
St Peter Port receives on average 825 mm of precipitation per year, spread over about 143 rainy days.
Is it sunny in St Peter Port?
St Peter Port gets on average 8.9 hours of sunshine per day, roughly 3,249 hours per year over 1940-2025.
What is the biggest single-day snowfall in St Peter Port?
The heaviest 24-hour snowfall measured in St Peter Port between 1940 and 2025 was 11 March 2013, with 12.5 cm.
Are there tropical nights in St Peter Port?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in St Peter Port.
What was the most extreme apparent temperature in St Peter Port?
In St Peter Port, between 1940 and 2025, the highest apparent temperature reached 24.3 °C on 10 August 2003, and the lowest was -14.1 °C on 12 January 1987.
Compare St Peter Port with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around St Peter Port