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
During the shift to September, a minor reduction in average high-temperature is observed, shifting from a very hot 97.3°F (36.3°C) in August to a hot 91.4°F (33°C). The nighttime temperature during September exhibits a clear drop from daytime highs, settling at a comfortable 61.3°F (16.3°C).Humidity
In September, the average relative humidity is 38%.Rainfall
The months with the least rainfall are June through September Rain falls for 1.1 days and accumulates 0.04" (1mm) of rain.Daylight
In Atwater, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:46 pm PDT.
Sunshine
In September, the average sunshine is 11.5h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
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?
What is the UV index intensity in September?
Average temperature in September
Atwater, CA
- Average high temperature in September: 91.4°F
The warmest month (with the highest average high temperature) is July (98.6°F).
The month with the lowest average high temperature is December (56.1°F).
- Average low temperature in September: 61.3°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).
Average pressure in September
Atwater, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Atwater, CA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is June (7.6mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).
Average humidity in September
Atwater, CA
- Average humidity in September: 38%
The month with the highest relative humidity is January (71%).
The month with the lowest relative humidity is July (34%).
Average rainfall in September
Atwater, CA
- Average rainfall in September: 0.04"
The wettest months (with the highest rainfall) are March and December (0.55").
The driest months (with the least rainfall) are June, July, August and September (0.04").
Average rainfall days in September
Atwater, CA
- Average rainfall days in September: 1.1 days
The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is June (0.5 days).
Average daylight in September /
Average sunshine in September
Atwater, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 3min
The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 12min).
Average sunshine days in September
Atwater, CA
- Average sunshine days in September: 28.5 days
The month with the most sunshine days is August (28.9 days).
The month with the least sunshine days is February (23 days).
Average UV index in September
Atwater, 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, February, November and December (UV index 3).
Average cloud cover in September
Atwater, CA
- Average cloud cover in September: 6
The month with the most cloud cover is December (Cloud cover 31).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
Atwater, 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).
Atwater, California, USA
Weather forecast for your location
2. Allow the app to use your location