San Joaquin County (Stockton)
September
Weather in San Joaquin County, California for September 2026
Your guide to San Joaquin County weather in September - trends and predictions
Until now, September 2026 in San Joaquin County is slightly cooler than the historical average by 1.2 °F.
The forecast for the upcoming days in San Joaquin County predicts a temperature of 33 °F, which is slightly above the historical average.
In general, the average temperature in San Joaquin County at the beginning of September is 33.1 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 31.7 °F by the end of September.
With an average of 2 rainy days, San Joaquin County experiences minimal rainfall in September.
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Temperatures
Rain 🌧️
More
28
Dry days
2
Rainy days
0
Snow days
32°/14°
Temperatures
16 km/h
Avg max wind
54 %
Avg humidity
San Joaquin County Weather September
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Temperatures trend during September in San Joaquin County
See the weather trend as well as the moving average line
September weather in San Joaquin County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 32° /14° | 0 mm | 8 | |
| Sept. 2 | Sunny | 31° /14° | 0 mm | 8 | |
| Sept. 3 | Sunny | 32° /14° | 0 mm | 8 | |
| Sept. 4 | Sunny | 34° /14° | 0 mm | 9 | |
| Sept. 5 |  Mist | 35° /14° | 0 mm | 8 | |
| Sept. 6 | Sunny | 34° /15° | 0 mm | 9 | |
| Sept. 7 | Sunny | 34° /14° | 0 mm | 8 | |
| Sept. 8 | Sunny | 34° /13° | 0 mm | 8 | |
| Sept. 9 |  Overcast | 34° /16° | 0 mm | 6 | |
| Sept. 10 | Mist | 34° /16° | 0 mm | 8 | |
| Sept. 11 | Sunny | 32° /13° | 0 mm | 8 | |
| Sept. 12 | Overcast | 33° /13° | 0 mm | 8 | |
| Sept. 13 | Mist | 32° /13° | 0 mm | 8 | |
| Sept. 14 |  Partly cloudy | 34° /14° | 0 mm | 8 | |
| Sept. 15 | Partly cloudy | 32° /14° | 0 mm | 8 | |
| Sept. 16 | Sunny | 30° /14° | 0 mm | 7 | |
| Sept. 17 | Sunny | 30° /13° | 0 mm | 7 | |
| Sept. 18 | Mist | 27° /14° | 1.9 mm | 6 | |
| Sept. 19 | Mist | 31° /14° | 0 mm | 7 | |
| Sept. 20 | Mist | 31° /13° | 0 mm | 6 | |
| Sept. 21 | Sunny | 31° /14° | 0 mm | 6.3 | |
| Sept. 22 | Sunny | 32° /14° | 0 mm | 6.4 | |
| Sept. 23 | Sunny | 35° /16° | 0 mm | 6.5 | |
| Sept. 24 | Sunny | 36° /20° | 0 mm | 6.2 | |
| Sept. 25 | Sunny | 32° /17° | 0 mm | 6.2 | |
| Sept. 26 | Sunny | 31° /17° | 0 mm | 7 | |
| Sept. 27 | Sunny | 28° /15° | 0 mm | 7 | |
| Sept. 28 | Sunny | 30° /15° | 0 mm | 8 | |
| Sept. 29 | Sunny | 32° /15° | 0 mm | 8 | |
| Sept. 30 | Sunny | 33° /16° | 0 mm | 8 | |
| Next | |||||
Important Notice
Our weather forecast for San Joaquin County in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the San Joaquin County forecast closer to your planned date for the most up-to-date weather information.
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San Joaquin County in September - FAQ
What are the expected maximum and minimum temperatures in San Joaquin County during September?
Expect warm days with temperatures around 32°, cooling to mild conditions of 14° after sunset. Perfect for those who enjoy warm weather.
How much rainfall should be expected in San Joaquin County during September?
Rainfall in San Joaquin County during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 2 days seeing any precipitation. Planning without the concern for rain is generally straightforward during this very dry period.
What are the typical wind conditions in San Joaquin County during September?
The average wind speed in San Joaquin County during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in San Joaquin County
Explore the daily rainfall trends and prepare for San Joaquin Countys September weather 💧
Typically, San Joaquin County has 2 rainy days in September with a total of 3.8 mm of rainfall.
UV exposure in San Joaquin County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is San Joaquin County?Get accurate weather forecasts for San Joaquin County, located at latitude 37.958 and longitude -121.291. Stay updated with localized weather information tailored for San Joaquin County.
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