Click on a day for an hourly weather forecast
The weather in Barstow in September is hot. The average temperatures are between 20°C and 32°C.
You can expect a few rainy days in Barstow during September, but usually the weather is comfortable in September.
Our weather forecast can give you a great sense of what weather to expect in Barstow in September 2025.
If you’re planning to visit Barstow in the near future, we highly recommend that you review the 14 day weather forecast for Barstow before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 13° / 5° | 2 | 29 | 0 | 15 mm | Ok | Barstow in January |
| February | 15° / 6° | 1 | 27 | 0 | 13 mm | Good | Barstow in February |
| March | 19° / 8° | 1 | 30 | 0 | 7 mm | Good | Barstow in March |
| April | 23° / 11° | 1 | 29 | 0 | 7 mm | Perfect | Barstow in April |
| May | 27° / 14° | 0 | 31 | 0 | 2 mm | Perfect | Barstow in May |
| June | 33° / 19° | 0 | 30 | 0 | 1 mm | Good | Barstow in June |
| July | 36° / 23° | 2 | 29 | 0 | 5 mm | Ok | Barstow in July |
| August | 36° / 23° | 1 | 30 | 0 | 5 mm | Ok | Barstow in August |
| September | 32° / 20° | 1 | 29 | 0 | 2 mm | Good | Barstow in September |
| October | 25° / 13° | 1 | 30 | 0 | 6 mm | Perfect | Barstow in October |
| November | 18° / 7° | 1 | 29 | 0 | 7 mm | Good | Barstow in November |
| December | 12° / 4° | 2 | 29 | 0 | 23 mm | Ok | Barstow in December |