September weather forecastCalais, Guernsey
September
Weather in September
With the arrival of September, Calais, Guernsey starts feeling the gradual shift towards autumn. A dip is noticed in the temperature, marking the onset of a cooler climate with temperature averaging between 15.4°C (59.7°F) and 17.2°C (63°F). The city experiences an increase in wind speeds, where wind gusts reaching up to 37.6km/h (23.4mph), a notable change from August’s 34.3km/h (21.3mph). A daylight decrease to 12.6 hours correlates with the shortening days characteristic of the season's change. Nonetheless, September enjoys a lasting summer vibe, despite the advent of autumn around the corner.Temperature
The high-temperature average in September for Calais is a still enjoyable 17.2°C (63°F), staying closely aligned with August's conditions. September notes an average low temperature of 15.4°C (59.7°F), subtly down from the daytime highs.Humidity
In September, the average relative humidity is 80%.Rainfall
In Calais, Guernsey, in September, during 13.5 rainfall days, 31mm (1.22") of precipitation is typically accumulated. Throughout the year, in Calais, Guernsey, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.Snowfall
February through December are months without snowfall.Daylight
In Calais, the average length of the day in September is 12h and 36min.On the first day of September, sunrise is at 06:26 and sunset at 19:53. On the last day of the month, sunrise is at 07:09 and sunset at 18:50 BST.
Sunshine
In September, the average sunshine is 8.4h.UV index
July through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Make use of precautions - It is urged to ward off sun damage. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Calais, 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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 18min).
- 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
Calais, 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
Calais, 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
Calais, 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
Calais, 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).
