September weather forecastSaint Sampson, Guernsey
September
Weather in September
The arrival of September heralds the commencement of autumn in Saint Sampson. The climate cools slightly from the summer's peak temperature, with the range set between 15.4°C (59.7°F) and 17.2°C (63°F). There's a slight increase in rainfall from August, recording a total of 31mm (1.22") precipitation. As the hours of daylight dwindle, the hue of September evenings starts to shift to more subdued tones. Despite the shortened sunlight duration, a fair amount of sunshine still graces the city.Temperature
As Saint Sampson, Guernsey, welcomes September, the average high-temperature stabilizes at a still enjoyable 17.2°C (63°F), showing little deviation from August's 17.8°C (64°F). Saint Sampson experiences a subtle drop in temperature during the September nights, recording an average of 15.4°C (59.7°F).Humidity
In Saint Sampson, the average relative humidity in September is 80%.Rainfall
In Saint Sampson, during September, the rain falls for 13.5 days and regularly aggregates up to 31mm (1.22") of precipitation. Throughout the year, in Saint Sampson, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.Snowfall
In Saint Sampson, Guernsey, snow does not fall in February through December.Daylight
In September, the average length of the day in Saint Sampson, Guernsey, 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
The average sunshine in September is 8.4h.UV index
The months with the highest UV index are July through September, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Saint Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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
Saint Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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 Sampson, 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).
