Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from a torrid 99.7°F (37.6°C) in August to a hot 93°F (33.9°C). Despite the hot September days, London's nights see an average temperature plunge to a comfortable 60.8°F (16°C).Humidity
In September, the average relative humidity in London is 33%.Rainfall
In London, in September, during 2.1 rainfall days, 0.24" (6mm) of precipitation is typically accumulated. In London, during the entire year, the rain falls for 62.1 days and collects up to 13.31" (338mm) of precipitation.Snowfall
In London, snow does not fall in January, March through December.Daylight
The average length of the day in September is 12h and 24min.On the first day of September, sunrise is at 6:29 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:42 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
In London, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: An average maximum UV index of 6 in September leads to these recommendations:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Frequently asked questions
How hot is it in London in September?
What is the average humidity in September in London?
How many days does it rain in September in London?
When it does not snow in London?
How many hours of daylight does London have in September?
When are sunrise and sunset in September in London?
How many hours of sunshine does London have in September?
What is the UV index intensity in September in London?
Average temperature in September
London, CA
- Average high temperature in September: 93°F
The warmest month (with the highest average high temperature) is July (100.4°F).
The month with the lowest average high temperature is December (56.3°F).
- Average low temperature in September: 60.8°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is December (41.7°F).
Average pressure in September
London, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
London, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is June (5.8mph).
The calmest months (with the lowest average wind speed) are January and December (4.1mph).
Average humidity in September
London, CA
- Average humidity in September: 33%
The month with the highest relative humidity is January (67%).
The months with the lowest relative humidity are July and August (30%).
Average rainfall in September
London, CA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is March (2.6").
The driest months (with the least rainfall) are June and August (0.08").
Average rainfall days in September
London, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (11 days).
The month with the least rainy days is August (0.9 days).
Average snowfall days in September
London, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
London, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 1min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
London, CA
- Average sunshine days in September: 27.6 days
The month with the most sunshine days is August (28.8 days).
The month with the least sunshine days is March (19.5 days).
Average UV index in September
London, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 3).
Average cloud cover in September
London, CA
- Average cloud cover in September: 6
The month with the most cloud cover is March (Cloud cover 29).
The months with the least cloud cover are July and August (Cloud cover 5).
Average visibility in September
London, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
London, California, USA
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