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 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 commencement of September records an average high-temperature of a still warm 79.3°F (26.3°C), barely varying from August's 79.9°F (26.6°C). South Santa Rosa experiences a substantial decline from the daytime high temperatures in September, settling on an average low of 55°F (12.8°C).Humidity
September is the least humid month, with an average relative humidity of 62%.Rainfall
June through September are months with the least rain when the rain falls for 1.7 days and typically aggregates up to 0.04" (1mm) of rain.Daylight
In South Santa Rosa, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of September, sunrise is at 7:06 am and sunset at 6:54 pm PDT.
Sunshine
The average sunshine in September is 11h.UV index
In South Santa Rosa, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 5 in September translates into these instructions:
Heed the precautions - Suggestions to avoid sunburn are made. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the least humid month in South Santa Rosa?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
South Santa Rosa, CA
- Average high temperature in September: 79.3°F
The warmest months (with the highest average high temperature) are July and August (79.9°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in September: 55°F
The months with the highest average low temperature are August and September (55°F).
The coldest month (with the lowest average low temperature) is December (42.4°F).
Average pressure in September
South Santa Rosa, 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
South Santa Rosa, CA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is May (6.8mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).
Average humidity in September
South Santa Rosa, CA
- Average humidity in September: 62%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (62%).
Average rainfall in September
South Santa Rosa, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is February (0.91").
The driest months (with the least rainfall) are June, July, August and September (0.04").
Average rainfall days in September
South Santa Rosa, CA
- Average rainfall days in September: 1.7 days
The month with the highest number of rainy days is March (8.7 days).
The month with the least rainy days is August (0.5 days).
Average daylight in September /
Average sunshine in September
South Santa Rosa, CA
- Average daylight in September: 12h and 2min
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
South Santa Rosa, CA
- Average sunshine days in September: 27.5 days
The month with the most sunshine days is June (27.7 days).
The month with the least sunshine days is March (20.8 days).
Average UV index in September
South Santa Rosa, 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
South Santa Rosa, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 38).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
South Santa Rosa, 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).
South Santa Rosa, California, USA
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