Santa Clara County (San Jose)
September
Weather in Santa Clara County for September 2025
Your guide to Santa Clara County weather in September - trends and predictions
In general, the average temperature in Santa Clara County at the beginning of September is 29.6 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 28.1 °F by the end of September.
Precipitation in Santa Clara County during September is a rare event, with an average of fewer than 2 rainy days.
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29
Dry days
1
Rainy days
0
Snow days
27°/13°
Temperatures
12 km/h
Avg max wind
65 %
Avg humidity
Santa Clara County in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  25° | 2  27° | 3 29° | 4  31° | 5 32° | 6  32° | 7  31° |
| 8 31° | 9 31° | 10 29° | 11 28° | 12 28° | 13 30° | 14 30° |
| 15 26° | 16 24° | 17 21° | 18 23° | 19 25° | 20 25° | 21 27° |
| 22 29° | 23 29° | 24 30° | 25 27° | 26 27° | 27 30° | 28 28° |
| 29 28° | 30  27° |
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Temperatures trend during September in Santa Clara County
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 | Overcast | 25° /14° | 0 mm | 6 | |
| Sept. 2 | Cloudy | 27° /12° | 0 mm | 7 | |
| Sept. 3 | Overcast | 29° /13° | 0 mm | 7 | |
| Sept. 4 | Mist | 31° /15° | 0 mm | 7 | |
| Sept. 5 | Cloudy | 32° /14° | 0 mm | 8 | |
| Sept. 6 | Sunny | 32° /15° | 0 mm | 8 | |
| Sept. 7 | Partly cloudy | 31° /14° | 0 mm | 8 | |
| Sept. 8 | Partly cloudy | 31° /14° | 0 mm | 8 | |
| Sept. 9 | Partly cloudy | 31° /13° | 0 mm | 8 | |
| Sept. 10 | Cloudy | 29° /12° | 0 mm | 7 | |
| Sept. 11 | Cloudy | 28° /12° | 0 mm | 7 | |
| Sept. 12 | Overcast | 28° /12° | 0 mm | 7 | |
| Sept. 13 | Mist | 30° /13° | 0 mm | 8 | |
| Sept. 14 | Cloudy | 30° /13° | 0 mm | 7 | |
| Sept. 15 | Cloudy | 26° /13° | 0 mm | 6 | |
| Sept. 16 | Overcast | 24° /13° | 0.6 mm | 5 | |
| Sept. 17 | Overcast | 21° /12° | 0 mm | 5 | |
| Sept. 18 | Mist | 23° /13° | 1.5 mm | 5 | |
| Sept. 19 | Mist | 25° /13° | 0 mm | 6 | |
| Sept. 20 | Overcast | 25° /13° | 0 mm | 6 | |
| Sept. 21 | Partly cloudy | 27° /12° | 0 mm | 7 | |
| Sept. 22 | Mist | 29° /13° | 0 mm | 7 | |
| Sept. 23 | Overcast | 29° /14° | 0 mm | 7 | |
| Sept. 24 | Overcast | 30° /15° | 0 mm | 7 | |
| Sept. 25 | Mist | 27° /13° | 0 mm | 7 | |
| Sept. 26 | Overcast | 27° /13° | 0 mm | 7 | |
| Sept. 27 | Mist | 30° /13° | 0 mm | 7 | |
| Sept. 28 | Cloudy | 28° /14° | 0 mm | 7 | |
| Sept. 29 | Overcast | 28° /13° | 0 mm | 7 | |
| Sept. 30 | Light rain shower | 27° /14° | 1 mm | 6 | |
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Important Notice
Our weather forecast for Santa Clara 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 Santa Clara County forecast closer to your planned date for the most up-to-date weather information.
Santa Clara County in September - FAQ
What are the expected maximum and minimum temperatures in Santa Clara County during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Santa Clara County during September?
Rainfall in Santa Clara County 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 Santa Clara County during September?
The average wind speed in Santa Clara County during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Santa Clara County
Explore the daily rainfall trends and prepare for Santa Clara Countys September weather 💧
UV exposure in Santa Clara County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Santa Clara County?Get accurate weather forecasts for Santa Clara County, located at latitude 37.339 and longitude -121.895. Stay updated with localized weather information tailored for Santa Clara County.
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