September weather forecastLondon, CA
September
Weather in September
The first month of the autumn, September, is also a hot month in London, California, with temperature in the range of an average low of 60.8°F (16°C) and an average high of 93°F (33.9°C).Temperature
September implies a soft temperature shift, with average high-temperatures reducing from August's fiery hot 99.7°F (37.6°C) to a tropical 93°F (33.9°C). September is characterized by a distinct thermal shift, with nighttime lows averaging at an enjoyable 60.8°F (16°C).Humidity
The average relative humidity in September is 33%.Rainfall
In London, during September, the rain falls for 2.1 days and regularly aggregates up to 0.24" (6mm) of precipitation. Throughout the year, there are 62.1 rainfall days, and 13.31" (338mm) of precipitation is accumulated.Snowfall
In London, snow does not fall in January, March through December.Daylight
In London, the average length of the day in September is 12h and 24min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:25 pm. On the last day of September, 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 of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: During September, 6 as the daily maximum UV index converts into the following advice:
Conform to measures and uphold sun safety traditions. Warding off skin and eye harm is necessary. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 24min
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 6min
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).
