Saint Peter Port weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Good
Best time to visit: June – September
What is the weather like in Saint Peter Port in September?
In September, Saint Peter Port is mild: daytime highs average 17 °C, and nights cool down to about 16 °C. The sea averages 17.2 °C – bracing, so a wetsuit helps for longer swims. Expect around 6 hours of sunshine a day. Rain is frequent, with about 9 rainy days and 55 mm in total. It is often windy, with gusts of around 34 km/h. All in all, September is a good month for a holiday in Saint Peter Port.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 82 | 76 | 47 |
| Day | 18° | 17° | 16° |
| Night | 16° | 16° | 14° |
| Sea | 17° | 17° | 16° |
| Sun | 7 h | 6 h | 4 h |
| Rain days | 9 | 9 | 15 |
More details for September
- Daylight
- 12 h 42 min06:45 – 19:26
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 34 km/haverage daily peakAll months
- Cloud cover
- 59 %on averageAll months
- Hot days
- 0 days30 °C or more
- Time zone
- UTC+1Europe/Guernsey
How the score comes together
- Temperatureweight 50 %92 %
- Sunshineweight 20 %55 %
- Few rainy daysweight 30 %64 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
- Windproof jacket
Saint Peter Port in September: quick answers
Is Saint Peter Port hot in September?
No. In September, Saint Peter Port is mild: daytime highs average 17 °C and nights drop to about 16 °C.
Can you swim in Saint Peter Port in September?
Only if you don't mind cold water: in September the sea averages just 17.2 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Saint Peter Port in September?
Rain is frequent, with about 9 rainy days and 55 mm in total.
Saint Peter Port month by month
The whole year in Saint Peter PortAll destinations: GuernseyWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences