San Bernardino County (Big Bear Lake)
September
Weather in San Bernardino County, California for September 2027
Your guide to San Bernardino County weather in September - trends and predictions
In general, the average temperature in San Bernardino County at the beginning of September is 24.4 °C. As the month progressed, temperatures tended to moderately fall, reaching an average of 22.8 °C by the end of September.
With an average of 4 rainy days, San Bernardino County experiences minimal rainfall in September.
Is September a good time to visit San Bernardino County? check out the best time to travel to San Bernardino County page.
✨ Is September a good time to visit San Bernardino County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
26
Dry days
4
Rainy days
0
Snow days
23°/14°
Temperatures
13 km/h
Avg max wind
40 %
Avg humidity
San Bernardino County Weather September
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Temperatures trend during September in San Bernardino County
See the weather trend as well as the moving average line
September weather in San Bernardino County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 26° /17° | 0 mm | 8 | |
| Sept. 2 |  Moderate rain | 24° /16° | 10.7 mm | 8 | |
| Sept. 3 |  Light rain | 24° /14° | 3.6 mm | 8 | |
| Sept. 4 | Light rain | 24° /15° | 5.9 mm | 8 | |
| Sept. 5 | Light rain | 25° /16° | 6.8 mm | 8 | |
| Sept. 6 | Light rain | 24° /17° | 9.4 mm | 5 | |
| Sept. 7 |  Patchy rain possible | 25° /17° | 0.7 mm | 5 | |
| Sept. 8 | Patchy light drizzle | 25° /17° | 1.1 mm | 6 | |
| Sept. 9 | Light rain | 24° /16° | 3 mm | 7 | |
| Sept. 10 | Patchy rain possible | 24° /14° | 1.6 mm | 8 | |
| Sept. 11 | Sunny | 23° /13° | 0.1 mm | 8 | |
| Sept. 12 |  Partly cloudy | 23° /13° | 0 mm | 8 | |
| Sept. 13 | Sunny | 23° /13° | 0 mm | 7 | |
| Sept. 14 | Sunny | 25° /14° | 0 mm | 8 | |
| Sept. 15 | Sunny | 23° /14° | 0 mm | 8 | |
| Sept. 16 | Sunny | 19° /11° | 0 mm | 6 | |
| Sept. 17 |  Cloudy | 20° /10° | 0 mm | 6 | |
| Sept. 18 | Sunny | 21° /11° | 0 mm | 7 | |
| Sept. 19 | Sunny | 21° /10° | 0 mm | 7 | |
| Sept. 20 |  Thundery outbreaks possible | 20° /11° | 0 mm | 4 | |
| Sept. 21 |  Overcast | 20° /11° | 0 mm | 7 | |
| Sept. 22 | Sunny | 21° /14° | 0 mm | 7 | |
| Sept. 23 | Patchy rain possible | 24° /16° | 1.6 mm | 7 | |
| Sept. 24 | Partly cloudy | 24° /17° | 0 mm | 7 | |
| Sept. 25 | Sunny | 24° /14° | 0 mm | 7 | |
| Sept. 26 | Sunny | 23° /13° | 0 mm | 6 | |
| Sept. 27 | Light rain | 22° /15° | 9.6 mm | 4 | |
| Sept. 28 | Sunny | 21° /13° | 0 mm | 7 | |
| Sept. 29 | Partly cloudy | 22° /13° | 0 mm | 7 | |
| Sept. 30 | Sunny | 24° /14° | 0 mm | 7 | |
| Next | |||||
Important Notice
Our weather forecast for San Bernardino 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 San Bernardino County forecast closer to your planned date for the most up-to-date weather information.
Change Month
San Bernardino County in September - FAQ
What are the expected maximum and minimum temperatures in San Bernardino County during September?
Enjoy moderate daytime temperatures of up to 23° 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 Bernardino County during September?
Moderate rainfall is anticipated in San Bernardino County during September, with a total of 54.1 mm spread over approximately 4 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in San Bernardino County during September?
The average wind speed in San Bernardino County during September is 13 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in San Bernardino County
Explore the daily rainfall trends and prepare for San Bernardino Countys September weather 💧
Typically, San Bernardino County has 4 rainy days in September with a total of 54.1 mm of rainfall.
UV exposure in San Bernardino County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in San Bernardino County
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