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
Transitioning from August to September, Cotati observes an average high-temperature of a still moderately hot 79.3°F (26.3°C), differing subtly from the previous month. Despite high daytime temperatures, the average temperature lowers to a fresh 55°F (12.8°C) during September nights.Humidity
With an average relative humidity of 62%, September is the least humid month.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 Cotati, 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 September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The maximum daily UV index of 5 in September converts into the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the least humid month?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
How many hours of daylight does Cotati have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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
Cotati, 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).
Cotati, California, USA
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