Weather in San Bernardino, California for September 2025
Beach Hazards Statement - See hour by hour.
Until now, September 2025 in San Bernardino is cooler than usual, with temperatures averaging 31.3 °F, this is -2.3 °F below the typical seasonal average.
Expect cooler weather in the next days in San Bernardino with the forecast suggesting a temperature of 30.5 °F, lower than the historical average.
In general, the average temperature in San Bernardino at the beginning of September is 35 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 28.4 °F by the end of September.
With an average of 3 rainy days, San Bernardino experiences minimal rainfall in September.
New! Chat with our AI weatherman - it’s amazing and free.
Official Weather Alert ⚠️
Temperatures
Rain 🌧️
More
San Bernardino Weather September
Temperatures trend during September in San Bernardino
September weather in San Bernardino day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Patchy rain possible | 36° /21° | 0.4 mm | 8 | |
| Sept. 2 |  Light rain | 36° /22° | 1.9 mm | 8 | |
| Sept. 3 | Light rain | 32° /19° | 1.8 mm | 7 | |
| Sept. 4 |  Sunny | 34° /19° | 0 mm | 8 | |
| Sept. 5 | Sunny | 35° /21° | 0 mm | 9 | |
| Sept. 6 | Sunny | 36° /21° | 0 mm | 9 | |
| Sept. 7 | Sunny | 36° /21° | 0 mm | 8 | |
| Sept. 8 |  Partly cloudy | 36° /22° | 0 mm | 8 | |
| Sept. 9 | Sunny | 35° /21° | 0 mm | 8 | |
| Sept. 10 |  Cloudy | 32° /19° | 0 mm | 7 | |
| Sept. 11 | Partly cloudy | 30° /18° | 0 mm | 7 | |
| Sept. 12 | Sunny | 30° /15° | 0 mm | 7 | |
| Sept. 13 | Sunny | 29° /14° | 0 mm | 7 | |
| Sept. 14 | Sunny | 31° /16° | 0 mm | 8 | |
| Sept. 15 | Sunny | 37° /18° | 0 mm | 2 | |
| Sept. 16 | Sunny | 37° /21° | 0 mm | 2 | |
| Sept. 17 |  Overcast | 35° /20° | 0 mm | 1.8 | |
| Sept. 18 |  Moderate rain | 30° /16° | 6.9 mm | 1.9 | |
| Sept. 19 | Patchy rain possible | 28° /20° | 4.4 mm | 0 | |
| Sept. 20 | Sunny | 31° /19° | 0 mm | 6 | |
| Sept. 21 | Sunny | 32° /19° | 0 mm | 6 | |
| Sept. 22 | Patchy rain possible | 29° /16° | 0.8 mm | 5 | |
| Sept. 23 | Sunny | 29° /16° | 0 mm | 6 | |
| Sept. 24 | Partly cloudy | 33° /16° | 0 mm | 6 | |
| Sept. 25 | Partly cloudy | 33° /19° | 0 mm | 6 | |
| Sept. 26 | Sunny | 30° /16° | 0 mm | 6 | |
| Sept. 27 | Patchy rain possible | 22° /12° | 0.2 mm | 4 | |
| Sept. 28 | Patchy rain possible | 21° /6° | 1.2 mm | 3 | |
| Sept. 29 | Sunny | 32° /16° | 0 mm | 8 | |
| Sept. 30 | Light rain shower | 28° /15° | 1.7 mm | 7 | |
| Next | |||||
San Bernardino in September - FAQ
September rainfall patterns in San Bernardino
UV exposure in San Bernardino during September
Quick links
Where is San Bernardino?Get accurate weather forecasts for San Bernardino, located at latitude 34.108 and longitude -117.29. Stay updated with localized weather information tailored for San Bernardino.