Vallejo weather in September: Vallejo, California: normal highs, lows, rain and records for September
Vallejo in September has a normal high of 86°F and a normal low of 57°F, a daily mean of 71°F, falling from 87°F on the 1st to 84°F by the 30th. The month brings 0.08 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 30°C and low of 14°C, 2 mm of precipitation in September.
- NOAA stationVallejo
- Station IDUSC00049219
- Location38.10°N 122.19°W
- Elevation341 ft (104 m)
- From the center4 miles
- Population123,475
- Jan 57° 42°
- Feb 63° 45°
- Mar 68° 46°
- Apr 73° 47°
- May 78° 51°
- Jun 83° 54°
- Jul 85° 56°
- Aug 86° 56°
- Sep 86° 57°
- Oct 79° 54°
- Nov 66° 47°
- Dec 58° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Vallejo in September?
The normal high is 86°F and the normal low 57°F, for a daily mean of 71.3°F. September is 0.2°F warmer than August and 5.0°F warmer than October. September is the warmest month of the year in Vallejo and the 10th wettest. Across the month the normal high falls 3°F, from 87°F on September 1 to 84°F on September 30.
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 87°F | 56°F | – | – |
| September 8 | 87°F | 57°F | – | – |
| September 15 | 87°F | 57°F | – | – |
| September 22 | 86°F | 57°F | – | – |
| September 30 | 84°F | 56°F | – | – |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 87°F | 56°F | – | – | 13 h |
| September 2 | 87°F | 56°F | – | – | 13 h |
| September 3 | 87°F | 56°F | – | – | 13 h |
| September 4 | 87°F | 56°F | – | – | 13 h |
| September 5 | 87°F | 56°F | – | – | 12 h 50 min |
| September 6 | 87°F | 56°F | – | – | 12 h 50 min |
| September 7 | 87°F | 56°F | – | – | 12 h 50 min |
| September 8 | 87°F | 57°F | – | – | 12 h 50 min |
| September 9 | 87°F | 57°F | – | – | 12 h 40 min |
| September 10 | 87°F | 57°F | – | – | 12 h 40 min |
| September 11 | 87°F | 57°F | – | – | 12 h 40 min |
| September 12 | 87°F | 57°F | – | – | 12 h 40 min |
| September 13 | 87°F | 57°F | – | – | 12 h 30 min |
| September 14 | 87°F | 57°F | – | – | 12 h 30 min |
| September 15 | 87°F | 57°F | – | – | 12 h 30 min |
| September 16 | 86°F | 57°F | – | – | 12 h 30 min |
| September 17 | 86°F | 57°F | – | – | 12 h 20 min |
| September 18 | 86°F | 57°F | – | – | 12 h 20 min |
| September 19 | 86°F | 57°F | – | – | 12 h 20 min |
| September 20 | 86°F | 57°F | – | – | 12 h 20 min |
| September 21 | 86°F | 57°F | – | – | 12 h 10 min |
| September 22 | 86°F | 57°F | – | – | 12 h 10 min |
| September 23 | 86°F | 57°F | – | – | 12 h 10 min |
| September 24 | 85°F | 57°F | – | – | 12 h 10 min |
| September 25 | 85°F | 57°F | – | – | 12 h 10 min |
| September 26 | 85°F | 57°F | – | – | 12 h |
| September 27 | 85°F | 56°F | – | – | 12 h |
| September 28 | 85°F | 56°F | – | – | 12 h |
| September 29 | 85°F | 56°F | – | – | 12 h |
| September 30 | 84°F | 56°F | – | – | 11 h 50 min |
- Normal high
- 86°FSeptember average
- Normal low
- 57°FSeptember average
- Precipitation
- 0.08 inmonth total
- Days at 90°F or more
- 10
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 29
- Days at 80°F or more
- 20
- Sunshine
- 93%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00049219; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Vallejo in September?
In a normal September in Vallejo, 10 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00049219.
What are the records for September in Vallejo?
The September mean against the 1991-2020 normal of 71.3°F: 2021 70.9°F (−0.4), 2022 74.2°F (+2.9), 2023 68.0°F (−3.3), 2024 71.2°F (−0.1), 2025 72.1°F (+0.8), 2026 69.7°F (−1.6). 2 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.9°F | −0.4°F | 0.01 in |
| 2022 | 74.2°F | +2.9°F | 0.24 in |
| 2023 | 68.0°F | −3.3°F | 0.16 in |
| 2024 | 71.2°F | −0.1°F | 0.00 in |
| 2025 | 72.1°F | +0.8°F | 0.10 in |
| 2026 | 69.7°F | −1.6°F | 0.24 in |
Source: recent months: ACIS, station USC00049219. Records and recent months use complete months only.
How does September in Vallejo compare across California?
Across the 219 places PlainClimate covers in California, September normal highs run from 64°F in Eureka to 104°F in Brawley; Vallejo's is 86°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.