September weather forecastSan Quentin, CA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in San Quentin, California, with temperature in the range of an average low of 56.1°F (13.4°C) and an average high of 72.3°F (22.4°C).Temperature
September registers as the month with the highest average temperatures, reaching 72.3°F (22.4°C) at its peak and 56.1°F (13.4°C) at the lowest.Humidity
In September, the average relative humidity is 71%.Rainfall
The months with the least rainfall are June through September Rain falls for 1.7 days and accumulates 0.04" (1mm) of rain.Daylight
In September, the average length of the day in San Quentin is 12h and 25min.On the first day of September, sunrise is at 6:40 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:53 pm PDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
The months with the highest UV index in San Quentin are April, June through September, with an average maximum UV index of 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: In September, the UV index of 5 transforms into the following advice:
Be vigilant - Preventing sunburn is recommended. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Quentin, CA
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is September (72.3°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is September (56.1°F).
The coldest month (with the lowest average low temperature) is December (45.3°F).
Average pressure in September
San Quentin, 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
San Quentin, CA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is May (7.8mph).
The calmest months (with the lowest average wind speed) are October and November (5.5mph).
Average humidity in September
San Quentin, CA
- Average humidity in September: 71%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
San Quentin, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July, August and September (0.04").
Average rainfall days in September
San Quentin, CA
- Average rainfall days in September: 1.7 days
The month with the highest number of rainy days is March (8.8 days).
The months with the least rainy days are June and August (1.2 days).
Average daylight in September /
Average sunshine in September
San Quentin, 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 36min).
- Average sunshine in September: 10h and 24min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
San Quentin, CA
- Average sunshine days in September: 26 days
The month with the most sunshine days is June (26.4 days).
The month with the least sunshine days is March (20.7 days).
Average UV index in September
San Quentin, CA
- Average UV index in September: 5
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
San Quentin, CA
- Average cloud cover in September: 19
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is September (Cloud cover 19).
Average visibility in September
San Quentin, 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).
