September weather in Vallejo, CA
The average temperature in Vallejo in September is 71.3°F (56.5°F–86.1°F). Average precipitation: 0.08 inches.
September is a fall month in Vallejo, and is warmer than the annual average of 61.6°F. Daily temperatures swing about 29.6°F between overnight low and afternoon high. Daylight averages about 12h 14m. For travel, September is a comfortable month to visit.
Avg High
86.1°F
Avg Low
56.5°F
Precipitation
0.08 in
Daylight
12h 14m
September records in Vallejo
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 113.0°F (2017) | 51.1°F (1999) | 0.00 in (1998) |
| September 2 | 113.0°F (2017) | 53.1°F (2002) | 0.00 in (1998) |
| September 3 | 111.9°F (2017) | 53.1°F (2003) | 0.00 in (1998) |
| September 4 | 102.9°F (2022) | 48.9°F (2000) | 0.00 in (1998) |
| September 5 | 111.9°F (2022) | 48.9°F (2000) | 0.00 in (1998) |
| September 6 | 111.9°F (2020) | 50.0°F (2002) | 0.00 in (1998) |
| September 7 | 111.9°F (2020) | 46.0°F (2002) | 0.00 in (1998) |
| September 8 | 107.1°F (2022) | 53.1°F (2001) | 0.00 in (1998) |
| September 9 | 108.0°F (2015) | 53.1°F (2003) | 0.00 in (1998) |
| September 10 | 106.0°F (2015) | 48.0°F (2002) | 0.01 in (2021) |
| September 11 | 100.0°F (2017) | 51.1°F (2002) | 0.00 in (1998) |
| September 12 | 98.1°F (2003) | 52.0°F (2002) | 0.00 in (1998) |
| September 13 | 102.0°F (2019) | 50.0°F (2002) | 0.00 in (1998) |
| September 14 | 99.0°F (2019) | 52.0°F (2002) | 0.00 in (1998) |
| September 15 | 95.0°F (2025) | 51.1°F (1999) | 0.00 in (1998) |
| September 16 | 93.0°F (2025) | 50.0°F (2018) | 0.04 in (2019) |
| September 17 | 97.0°F (2025) | 48.9°F (2003) | 0.00 in (1998) |
| September 18 | 104.0°F (2016) | 48.9°F (2003) | 0.05 in (2022) |
| September 19 | 102.0°F (2016) | 44.1°F (2004) | 0.10 in (2022) |
| September 20 | 102.9°F (2015) | 51.1°F (1998) | 0.00 in (1998) |
| September 21 | 104.0°F (2015) | 44.1°F (2004) | 0.09 in (2022) |
| September 22 | 102.9°F (2003) | 48.0°F (2004) | 0.10 in (2000) |
| September 23 | 98.1°F (2003) | 50.0°F (2023) | 0.00 in (1998) |
| September 24 | 100.0°F (2019) | 50.0°F (2002) | 0.00 in (1998) |
| September 25 | 99.0°F (2019) | 50.0°F (2000) | 0.40 in (2001) |
| September 26 | 104.0°F (2016) | 48.9°F (2002) | 0.00 in (1998) |
| September 27 | 100.9°F (2016) | 51.1°F (1998) | 0.00 in (1998) |
| September 28 | 100.0°F (2020) | 48.0°F (2001) | 0.00 in (1998) |
| September 29 | 97.0°F (1999) | 46.0°F (2019) | 0.05 in (1998) |
| September 30 | 97.0°F (2024) | 48.0°F (2001) | 0.16 in (2023) |