Riverside County (Riverside)
September
Weather in Riverside County for September 2025
Your guide to Riverside County weather in September - trends and predictions
In general, the average temperature in Riverside County at the beginning of September is 33.4 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 31.3 °F by the end of September.
With an average of 3 rainy days, Riverside County experiences minimal rainfall in September.
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27
Dry days
3
Rainy days
0
Snow days
29°/17°
Temperatures
16 km/h
Avg max wind
54 %
Avg humidity
Riverside County in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  33° | 2  32° | 3  31° | 4  32° | 5 34° | 6 36° | 7  36° |
| 8 37° | 9 38° | 10 35° | 11 33° | 12 30° | 13 30° | 14 29° |
| 15 28° | 16  25° | 17 24° | 18 24° | 19 24° | 20 23° | 21 24° |
| 22 29° | 23 33° | 24 32° | 25 32° | 26 31° | 27 32° | 28 32° |
| 29 32° | 30 28° |
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Temperatures trend during September in Riverside 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 | Patchy rain possible | 33° /21° | 0.5 mm | 8 | |
| Sept. 2 | Overcast | 32° /22° | 0 mm | 8 | |
| Sept. 3 | Light rain | 31° /20° | 1.1 mm | 8 | |
| Sept. 4 | Cloudy | 32° /20° | 0 mm | 8 | |
| Sept. 5 | Cloudy | 34° /22° | 0 mm | 8 | |
| Sept. 6 | Cloudy | 36° /23° | 0 mm | 9 | |
| Sept. 7 | Sunny | 36° /23° | 0 mm | 8 | |
| Sept. 8 | Sunny | 37° /25° | 0.1 mm | 9 | |
| Sept. 9 | Sunny | 38° /26° | 0 mm | 9 | |
| Sept. 10 | Cloudy | 35° /25° | 0 mm | 8 | |
| Sept. 11 | Cloudy | 33° /22° | 0 mm | 8 | |
| Sept. 12 | Sunny | 30° /19° | 0 mm | 8 | |
| Sept. 13 | Sunny | 30° /18° | 0 mm | 8 | |
| Sept. 14 | Sunny | 29° /17° | 0 mm | 8 | |
| Sept. 15 | Cloudy | 28° /16° | 0 mm | 7 | |
| Sept. 16 | Partly cloudy | 25° /15° | 0.1 mm | 7 | |
| Sept. 17 | Cloudy | 24° /13° | 0 mm | 6 | |
| Sept. 18 | Overcast | 24° /13° | 0 mm | 6 | |
| Sept. 19 | Overcast | 24° /14° | 0 mm | 5 | |
| Sept. 20 | Cloudy | 23° /14° | 0 mm | 6 | |
| Sept. 21 | Patchy rain possible | 24° /13° | 0 mm | 6 | |
| Sept. 22 | Overcast | 29° /14° | 0 mm | 7 | |
| Sept. 23 | Partly cloudy | 33° /18° | 0 mm | 9 | |
| Sept. 24 | Partly cloudy | 32° /17° | 0 mm | 8 | |
| Sept. 25 | Sunny | 32° /17° | 0 mm | 8 | |
| Sept. 26 | Overcast | 31° /15° | 0 mm | 8 | |
| Sept. 27 | Partly cloudy | 32° /17° | 0 mm | 8 | |
| Sept. 28 | Sunny | 32° /17° | 0 mm | 8 | |
| Sept. 29 | Sunny | 32° /17° | 0 mm | 8 | |
| Sept. 30 | Light rain shower | 28° /16° | 1 mm | 7 | |
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Important Notice
Our weather forecast for Riverside 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 Riverside County forecast closer to your planned date for the most up-to-date weather information.
Riverside County in September - FAQ
What are the expected maximum and minimum temperatures in Riverside County during September?
During September, expect a variety of temperatures with highs around 29° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Riverside County during September?
Rainfall in Riverside County during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 3 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 Riverside County during September?
The average wind speed in Riverside County during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Riverside County
Explore the daily rainfall trends and prepare for Riverside Countys September weather 💧
UV exposure in Riverside County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Riverside County?Get accurate weather forecasts for Riverside County, located at latitude 33.953 and longitude -117.396. Stay updated with localized weather information tailored for Riverside County.
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