September weather forecastClos du Valle, Guernsey
September weather for Clos du Valle, Guernsey: In Clos du Valle, in September, during 13.5 rainfall days, 31mm (1.22") of precipitation is typically accumulated. In September, the average high-temperature and low-temperature in Clos du Valle, Guernsey, are 17.2°C (63°F) and 15.4°C (59.7°F) respectively.
September
Weather in September
Entering September, Guernsey experiences a gradual farewell to the summer heat. The most prominent shift during this month is the receding daylight, dropping from August's 14.4 hours to 12.6 hours. Nature begins to display the initial signs of autumn. While relatively fewer visitors tour during this time, the tranquil weather provides a peaceful yet delightful journey. The manifesting autumn colors make every sight more picturesque and memorable.Temperature
Clos du Valle marks the onset of September with an average high-temperature of a still comfortable 17.2°C (63°F), a subtle shift from August's 17.8°C (64°F). Clos du Valle notes a consistent average low-temperature of 15.4°C (59.7°F) during September nights.Humidity
In Clos du Valle, the average relative humidity in September is 80%.Rainfall
In September, the rain falls for 13.5 days. Throughout September, 31mm (1.22") of precipitation is accumulated. Throughout the year, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.Snowfall
In Clos du Valle, snow does not fall in February through December.Daylight
In September, the average length of the day 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, sunrise is at 07:09 and sunset at 18:50 BST.
Sunshine
In Clos du Valle, the average sunshine in September is 8.4h.UV index
The months with the highest UV index in Clos du Valle are July through September, with an average maximum UV index of 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: A maximum high UV index of 5 in September translates into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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 daylight in September /
Average sunshine in September
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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
Clos du Valle, 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).





