September weather forecastLes Quartiers, Guernsey
September
Weather in September
The arrival of September in Les Quartiers, Guernsey heralds the onset of autumn bringing gradual changes in its stride. It marks the end of the peak summer temperatures with a considerable drop from August, signaling the onset of cooler days ahead. The spotlight falls upon the remarkable increase in rainfall up to 58mm (2.28"), heralding the beginning of the rainier season. A week into October, expect temperatures to keep dropping alongside a rise in rainfall. However, the decreased daylight length is compensated by relatively longer sunshine hours.Temperature
In September, Les Quartiers experiences a barely noticeable shift in meteorological conditions, with average high-temperatures moving from 17.8°C (64°F) in August to a still comfortable 17.2°C (63°F). With a barely noticeable fluctuation in temperature, Les Quartiers reaches an average low of 15.4°C (59.7°F) during the September nights.Humidity
The average relative humidity in September is 80%.Rainfall
In Les Quartiers, during September, the rain falls for 13.5 days and regularly aggregates up to 31mm (1.22") of precipitation. Throughout the year, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.Snowfall
In Les Quartiers, snow does not fall in February through December.Daylight
In Les Quartiers, 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, 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 reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: The daily high UV index of 5 during September translates into the following recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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
Les Quartiers, 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).
