September weather forecastSebastopol, CA
September
Weather in September
September, the first month of the autumn in Sebastopol, is still a warm month, with temperature in the range of an average high of 79°F (26.1°C) and an average low of 54.7°F (12.6°C).Temperature
On the advent of September, Sebastopol's average high-temperature exhibits a minor adjustment to a still warm 79°F (26.1°C) from August's 79.7°F (26.5°C). September witnesses a substantial contrast between the daytime highs and the average low of 54.7°F (12.6°C).Humidity
The least humid month is September, with an average relative humidity of 63%.Rainfall
In Sebastopol, during September, the rain falls for 2.8 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 72.8 rainfall days, and 12.01" (305mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:55 pm PDT.
Sunshine
In September, the average sunshine is 11h.UV index
In Sebastopol, California, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sebastopol, CA
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in September: 54.7°F
The months with the highest average low temperature are August and September (54.7°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).
Average pressure in September
Sebastopol, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Sebastopol, CA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).
Average humidity in September
Sebastopol, CA
- Average humidity in September: 63%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (63%).
Average rainfall in September
Sebastopol, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (2.64").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Sebastopol, CA
- Average rainfall days in September: 2.8 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.8 days).
Average daylight in September /
Average sunshine in September
Sebastopol, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Sebastopol, CA
- Average sunshine days in September: 26.5 days
The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (17.1 days).
Average UV index in September
Sebastopol, CA
- Average UV index in September: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Sebastopol, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Sebastopol, 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).
