San Jose (CA)
September
Weather in San Jose, California for September 2026
Your guide to San Jose weather in September - trends and predictions
Until now, September 2026 in San Jose is slightly cooler than the historical average by 0.7 °F.
The forecast for the next days in San Jose predicts temperatures to be around 28 °F, close to the historical average.
In general, the average temperature in San Jose at the beginning of September is 28.1 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 25.3 °F by the end of September.
Precipitation in San Jose during September is a rare event, with an average of fewer than 2 rainy days.
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Temperatures
Rain 🌧️
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29
Dry days
1
Rainy days
0
Snow days
27°/14°
Temperatures
12 km/h
Avg max wind
63 %
Avg humidity
San Jose Weather September
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Temperatures trend during September in San Jose
See the weather trend as well as the moving average line
September weather in San Jose day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 26° /14° | 0.1 mm | 6 | |
| Sept. 2 | Sunny | 27° /13° | 0 mm | 7 | |
| Sept. 3 |  Overcast | 29° /14° | 0 mm | 7 | |
| Sept. 4 | Sunny | 29° /14° | 0 mm | 8 | |
| Sept. 5 | Sunny | 28° /13° | 0 mm | 7 | |
| Sept. 6 | Sunny | 29° /14° | 0 mm | 8 | |
| Sept. 7 | Sunny | 29° /14° | 0 mm | 7 | |
| Sept. 8 | Overcast | 29° /14° | 0 mm | 6 | |
| Sept. 9 | Overcast | 30° /15° | 0 mm | 6 | |
| Sept. 10 | Overcast | 29° /15° | 0 mm | 7 | |
| Sept. 11 | Sunny | 32° /15° | 0 mm | 8 | |
| Sept. 12 | Sunny | 28° /13° | 0 mm | 8.2 | |
| Sept. 13 | Sunny | 25° /11° | 0 mm | 7.6 | |
| Sept. 14 | Sunny | 30° /13° | 0 mm | 7.2 | |
| Sept. 15 | Sunny | 31° /11° | 0 mm | 8 | |
| Sept. 16 | Sunny | 29° /12° | 0 mm | 7 | |
| Sept. 17 | Sunny | 30° /13° | 0 mm | 8 | |
| Sept. 18 | Sunny | 31° /15° | 0 mm | 8 | |
| Sept. 19 | Sunny | 26° /13° | 0 mm | 7 | |
| Sept. 20 | Sunny | 26° /11° | 0 mm | 7 | |
| Sept. 21 | Sunny | 32° /15° | 0 mm | 8 | |
| Sept. 22 | Sunny | 35° /16° | 0 mm | 9 | |
| Sept. 23 | Sunny | 23° /10° | 0 mm | 6 | |
| Sept. 24 | Sunny | 18° /11° | 0.3 mm | 5 | |
| Sept. 25 |  Mist | 26° /14° | 0 mm | 6 | |
| Sept. 26 |  Partly cloudy | 28° /13° | 0 mm | 7 | |
| Sept. 27 | Sunny | 29° /14° | 0 mm | 7 | |
| Sept. 28 |  Cloudy | 25° /14° | 0 mm | 6 | |
| Sept. 29 | Overcast | 26° /14° | 0 mm | 6 | |
| Sept. 30 |  Light rain shower | 25° /15° | 0.7 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for San Jose 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 Jose forecast closer to your planned date for the most up-to-date weather information.
Change Month
San Jose in September - FAQ
What are the expected maximum and minimum temperatures in San Jose during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in San Jose during September?
Rainfall in San Jose during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 1 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 Jose during September?
The average wind speed in San Jose during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
UV exposure in San Jose during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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