Rancho Cucamonga
September
Weather in Rancho Cucamonga for September 2025
Your guide to Rancho Cucamonga weather in September - trends and predictions
In general, the average temperature in Rancho Cucamonga at the beginning of September is 33.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 30.3 °F by the end of September.
With an average of 4 rainy days, Rancho Cucamonga experiences minimal rainfall in September, ensuring that most days remain pleasantly dry.
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26
Dry days
4
Rainy days
0
Snow days
28°/16°
Temperatures
15 km/h
Avg max wind
54 %
Avg humidity
Rancho Cucamonga in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  33° | 2  32° | 3 31° | 4  32° | 5 35° | 6 36° | 7  36° |
| 8 37° | 9 37° | 10  35° | 11 32° | 12 30° | 13 28° | 14 29° |
| 15 28° | 16 26° | 17 24° | 18  23° | 19 22° | 20 23° | 21 23° |
| 22 28° | 23 32° | 24 31° | 25 31° | 26 31° | 27 32° | 28 30° |
| 29 30° | 30 27° |
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Temperatures trend during September in Rancho Cucamonga
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° /20° | 1.5 mm | 8 | |
| Sept. 2 | Light rain | 32° /20° | 1.1 mm | 8 | |
| Sept. 3 | Light rain | 31° /18° | 2.7 mm | 8 | |
| Sept. 4 | Partly cloudy | 32° /18° | 0 mm | 8 | |
| Sept. 5 | Partly cloudy | 35° /20° | 0 mm | 9 | |
| Sept. 6 | Partly cloudy | 36° /20° | 0 mm | 9 | |
| Sept. 7 | Sunny | 36° /22° | 0 mm | 9 | |
| Sept. 8 | Partly cloudy | 37° /22° | 0 mm | 8 | |
| Sept. 9 | Sunny | 37° /24° | 0 mm | 9 | |
| Sept. 10 | Overcast | 35° /22° | 0 mm | 8 | |
| Sept. 11 | Partly cloudy | 32° /19° | 0 mm | 8 | |
| Sept. 12 | Sunny | 30° /17° | 0 mm | 8 | |
| Sept. 13 | Sunny | 28° /15° | 0 mm | 7 | |
| Sept. 14 | Sunny | 29° /16° | 0 mm | 7 | |
| Sept. 15 | Partly cloudy | 28° /15° | 0 mm | 7 | |
| Sept. 16 | Partly cloudy | 26° /14° | 0.1 mm | 7 | |
| Sept. 17 | Partly cloudy | 24° /15° | 0 mm | 6 | |
| Sept. 18 | Cloudy | 23° /14° | 0 mm | 6 | |
| Sept. 19 | Partly cloudy | 22° /14° | 0 mm | 6 | |
| Sept. 20 | Partly cloudy | 23° /13° | 0 mm | 6 | |
| Sept. 21 | Patchy rain possible | 23° /13° | 0.1 mm | 6 | |
| Sept. 22 | Overcast | 28° /14° | 0 mm | 7 | |
| Sept. 23 | Partly cloudy | 32° /18° | 0 mm | 8 | |
| Sept. 24 | Sunny | 31° /17° | 0 mm | 8 | |
| Sept. 25 | Sunny | 31° /17° | 0 mm | 8 | |
| Sept. 26 | Overcast | 31° /16° | 0 mm | 7 | |
| Sept. 27 | Partly cloudy | 32° /17° | 0 mm | 8 | |
| Sept. 28 | Sunny | 30° /17° | 0 mm | 8 | |
| Sept. 29 | Sunny | 30° /17° | 0 mm | 8 | |
| Sept. 30 | Light rain shower | 27° /17° | 1.8 mm | 7 | |
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Important Notice
Our weather forecast for Rancho Cucamonga 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 Rancho Cucamonga forecast closer to your planned date for the most up-to-date weather information.
Rancho Cucamonga in September - FAQ
What are the expected maximum and minimum temperatures in Rancho Cucamonga during September?
During September, expect a variety of temperatures with highs around 28° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in Rancho Cucamonga during September?
Expect minimal rainfall in Rancho Cucamonga during September, with a total of 14.4 mm over approximately 4 days. This minimal precipitation is unlikely to significantly impact plans.
What are the typical wind conditions in Rancho Cucamonga during September?
The average wind speed in Rancho Cucamonga during September is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Rancho Cucamonga
Explore the daily rainfall trends and prepare for Rancho Cucamongas September weather 💧
UV exposure in Rancho Cucamonga during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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