Weather in Sunnyvale, California for September 2026
Until now, September 2026 in Sunnyvale has been nearly identical to the historical average, with a temperature of 27 °F (showing only a slight deviation of 0.4 °F).
The forecast for the upcoming days in Sunnyvale predicts a temperature of 29.6 °F, which is slightly above the historical average.
In general, the average temperature in Sunnyvale at the beginning of September is 27.3 °F. As the month progressed, temperatures tended to moderately rise, reaching an average of 28 °F by the end of September.
With an average of 2 rainy days, Sunnyvale experiences minimal rainfall in September.
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Sunnyvale Weather September
Temperatures trend during September in Sunnyvale
September weather in Sunnyvale day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 25° /13° | 0.1 mm | 6 | |
| Sept. 2 |  Sunny | 26° /14° | 0 mm | 7 | |
| Sept. 3 | Sunny | 28° /14° | 0 mm | 7 | |
| Sept. 4 | Sunny | 29° /14° | 0 mm | 8 | |
| Sept. 5 | Overcast | 27° /13° | 0 mm | 7 | |
| Sept. 6 | Sunny | 28° /14° | 0 mm | 8 | |
| Sept. 7 | Sunny | 28° /14° | 0 mm | 7 | |
| Sept. 8 | Overcast | 28° /14° | 0 mm | 7 | |
| Sept. 9 | Overcast | 28° /15° | 0 mm | 5 | |
| Sept. 10 |  Mist | 27° /15° | 1 mm | 6 | |
| Sept. 11 | Overcast | 24° /14° | 0 mm | 6 | |
| Sept. 12 | Overcast | 26° /13° | 0 mm | 7 | |
| Sept. 13 | Mist | 25° /13° | 0 mm | 7 | |
| Sept. 14 |  Cloudy | 28° /13° | 0 mm | 7 | |
| Sept. 15 | Overcast | 28° /13° | 0 mm | 7 | |
| Sept. 16 | Sunny | 26° /14° | 0.3 mm | 6 | |
| Sept. 17 | Overcast | 24° /13° | 0 mm | 6 | |
| Sept. 18 | Mist | 24° /14° | 4.9 mm | 6 | |
| Sept. 19 | Mist | 27° /13° | 0 mm | 6 | |
| Sept. 20 | Overcast | 25° /13° | 0 mm | 5 | |
| Sept. 21 | Sunny | 28° /11° | 0 mm | 6.7 | |
| Sept. 22 | Sunny | 29° /11° | 0 mm | 6.7 | |
| Sept. 23 | Sunny | 31° /13° | 0 mm | 6.8 | |
| Sept. 24 | Sunny | 33° /16° | 0 mm | 6.5 | |
| Sept. 25 | Sunny | 28° /14° | 0 mm | 6.4 | |
| Sept. 26 | Overcast | 29° /13° | 0 mm | 6 | |
| Sept. 27 | Sunny | 23° /11° | 0 mm | 6 | |
| Sept. 28 | Sunny | 26° /12° | 0 mm | 7 | |
| Sept. 29 | Sunny | 27° /13° | 0 mm | 7 | |
| Sept. 30 | Sunny | 30° /13° | 0 mm | 7 | |
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Sunnyvale in September - FAQ
What are the expected maximum and minimum temperatures in Sunnyvale during September?
How much rainfall should be expected in Sunnyvale during September?
What are the typical wind conditions in Sunnyvale during September?
September rainfall patterns in Sunnyvale
UV exposure in Sunnyvale during September
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Where is Sunnyvale?Get accurate weather forecasts for Sunnyvale, located at latitude 37.369 and longitude -122.036. Stay updated with localized weather information tailored for Sunnyvale.