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The weather in San Bernardino in August is hot. The average temperatures are between 16°C and 34°C. Usually the days in August are hot while the nights are a bit cooler.
There shouldn't be any rainy days in in San Bernardino during August. Having said that, the days are very hot in August so hanging out outside is more recomanded during the after noons and evening time.
Our weather forecast can give you a great sense of what weather to expect in San Bernardino in August 2025.
If you’re planning to visit San Bernardino in the near future, we highly recommend that you review the 14 day weather forecast for San Bernardino before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 18° / 5° | 2 | 29 | 0 | 50 mm | Good | San Bernardino in January |
| February | 18° / 5° | 2 | 26 | 0 | 55 mm | Good | San Bernardino in February |
| March | 20° / 5° | 2 | 29 | 0 | 31 mm | Good | San Bernardino in March |
| April | 23° / 7° | 1 | 29 | 0 | 23 mm | Perfect | San Bernardino in April |
| May | 26° / 9° | 0 | 31 | 0 | 7 mm | Perfect | San Bernardino in May |
| June | 31° / 12° | 0 | 30 | 0 | 2 mm | Good | San Bernardino in June |
| July | 34° / 15° | 1 | 30 | 0 | 18 mm | Ok | San Bernardino in July |
| August | 34° / 16° | 0 | 31 | 0 | 10 mm | Ok | San Bernardino in August |
| September | 32° / 14° | 0 | 30 | 0 | 7 mm | Good | San Bernardino in September |
| October | 27° / 10° | 0 | 31 | 0 | 8 mm | Perfect | San Bernardino in October |
| November | 22° / 7° | 1 | 29 | 0 | 18 mm | Good | San Bernardino in November |
| December | 17° / 4° | 3 | 28 | 0 | 63 mm | Good | San Bernardino in December |