September weather forecastSaint Peter Port, Guernsey
September weather for Saint Peter Port, Guernsey: July through September, with an average maximum UV index of 5, are months with the highest UV index in Saint Peter Port, Guernsey. In Saint Peter Port, in September, during 13.5 rainfall days, 31mm (1.22") of precipitation is typically accumulated.
September
Weather in September
As summer begins to recede in Saint Peter Port, Guernsey, September brings a gentle mix of warmth and freshness in the air. Rainfall records a slight decrease to 31mm (1.22") over relatively fewer days. The daylight hours start to dwindle, heralding the slow approach of winter. Notwithstanding the slight reduction in temperatures, pleasant sea temperatures continue to accommodate water-based activities throughout September.Temperature
In the transition from August to September, Saint Peter Port reports an average high-temperature of a still comfortable 17.2°C (63°F), indicating a close resemblance to the prior month. Registering an almost steady temperature, Saint Peter Port's nights in September see an average low of 15.4°C (59.7°F).Humidity
In September, the average relative humidity in Saint Peter Port is 80%.Rainfall
In Saint Peter Port, in September, during 13.5 rainfall days, 31mm (1.22") of precipitation is typically accumulated. Throughout the year, in Saint Peter Port, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.Snowfall
February through December are months without snowfall in Saint Peter Port.Sea temperature
In Saint Peter Port, the average seawater temperature in September is 16°C (60.8°F).Note: Most people find it challenging to enjoy swimming in water that is 16°C (60.8°F). As water temperature falls below 21°C (69.8°F), controlling breathing grows increasingly difficult.
Daylight
In Saint Peter Port, the average length of the day in September is 12h and 36min.On the first day of the month, sunrise is at 06:26 and sunset at 19:53. On the last day of September, in Saint Peter Port, sunrise is at 07:09 and sunset at 18:50 BST.
Sunshine
The average sunshine in September in Saint Peter Port is 8.4h.UV index
July through September, with an average maximum UV index of 5, are months with the highest UV index in Saint Peter Port, Guernsey. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Enhance your sun protection with tightly woven, yet airy clothing.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Saint Peter Port, Guernsey
- Average high temperature in September: 17.2°C
The warmest month (with the highest average high temperature) is August (17.8°C).
The month with the lowest average high temperature is February (9.2°C).
- Average low temperature in September: 15.4°C
The month with the highest average low temperature is August (15.8°C).
The coldest month (with the lowest average low temperature) is February (7°C).
Average pressure in September
Saint Peter Port, Guernsey
- Average pressure in September: 1017.9mbar
The month with the highest atmospheric pressure is September (1017.9mbar).
The month with the lowest atmospheric pressure is November (1011.5mbar).
Average wind speed in September
Saint Peter Port, Guernsey
- Average wind speed in September: 25.8km/h
The windiest month (with the highest average wind speed) is December (36km/h).
The calmest month (with the lowest average wind speed) is July (21.9km/h).
Average humidity in September
Saint Peter Port, Guernsey
- Average humidity in September: 80%
The months with the highest relative humidity are June and July (84%).
The months with the lowest relative humidity are November and December (77%).
Average rainfall in September
Saint Peter Port, Guernsey
- Average rainfall in September: 31mm
The wettest month (with the highest rainfall) is November (87mm).
The driest month (with the least rainfall) is July (26mm).
Average rainfall days in September
Saint Peter Port, Guernsey
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is November (22.8 days).
The month with the least rainy days is June (11.5 days).
Average snowfall in September
Saint Peter Port, Guernsey
- Average snowfall in September: 0mm
The month with the highest snowfall is January (2mm).
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0mm).
Average snowfall days in September
Saint Peter Port, Guernsey
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average sea temperature in September
Saint Peter Port, Guernsey
- Average sea temperature in September: 16°C
The best month for swimming (with the highest average sea temperature) is August (17°C).
The coldest months (with the lowest average sea temperature) are February and March (9°C).
Average daylight in September /
Average sunshine in September
Saint Peter Port, Guernsey
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 12min).
The month with the shortest days is December (Average daylight: 8h and 12min).
- Average sunshine in September: 8h and 24min
The month with the most sunshine is July (Average sunshine: 9h and 42min).
The months with the least sunshine are January, November and December (Average sunshine: 3h and 54min).
Average sunshine days in September
Saint Peter Port, Guernsey
- Average sunshine days in September: 13.1 days
The month with the most sunshine days is May (16.3 days).
The month with the least sunshine days is November (4 days).
Average UV index in September
Saint Peter Port, Guernsey
- Average UV index in September: 5
The months with the highest UV index are July, August and September (UV index 5).
The month with the lowest UV index is February (UV index 2).
Average cloud cover in September
Saint Peter Port, Guernsey
- Average cloud cover in September: 41
The months with the most cloud cover are November and December (Cloud cover 63).
The month with the least cloud cover is July (Cloud cover 37).
Average visibility in September
Saint Peter Port, Guernsey
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
