Fairfield weather in September: Fairfield, California: normal highs, lows, rain and records for September
Fairfield in September has a normal high of 87°F and a normal low of 57°F, a daily mean of 72°F, falling from 89°F on the 1st to 84°F by the 30th. Measurable precipitation falls on 1 days in a normal September, 0.08 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 31°C and low of 14°C, 2 mm of precipitation in September.
- NOAA stationFairfield
- Station IDUSC00042934
- Location38.27°N 122.07°W
- Elevation40 ft (12 m)
- Population122,646
- Jan 57° 40°
- Feb 62° 43°
- Mar 66° 45°
- Apr 71° 48°
- May 78° 52°
- Jun 85° 56°
- Jul 90° 58°
- Aug 89° 58°
- Sep 87° 57°
- Oct 78° 52°
- Nov 66° 45°
- Dec 57° 40°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Fairfield in September?
The normal high is 87°F and the normal low 57°F, for a daily mean of 71.7°F. September is 1.9°F cooler than August and 6.5°F warmer than October. September is the 3rd warmest month of the year in Fairfield and the 10th wettest. Across the month the normal high falls 5°F, from 89°F on September 1 to 84°F on September 30. From one year to the next September's mean temperature typically moves about 1.6°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 70°F and 73°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 5%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 89°F | 58°F | 1% | 0% |
| September 8 | 88°F | 57°F | 1% | 1% |
| September 15 | 87°F | 57°F | 2% | 1% |
| September 22 | 86°F | 56°F | 3% | 2% |
| September 30 | 84°F | 55°F | 5% | 3% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 89°F | 58°F | 1% | 0% | 13 h |
| September 2 | 89°F | 58°F | 1% | 0% | 13 h |
| September 3 | 89°F | 58°F | 1% | 0% | 13 h |
| September 4 | 89°F | 58°F | 1% | 0% | 13 h |
| September 5 | 89°F | 57°F | 1% | 0% | 12 h 50 min |
| September 6 | 89°F | 57°F | 1% | 0% | 12 h 50 min |
| September 7 | 88°F | 57°F | 1% | 1% | 12 h 50 min |
| September 8 | 88°F | 57°F | 1% | 1% | 12 h 50 min |
| September 9 | 88°F | 57°F | 2% | 1% | 12 h 40 min |
| September 10 | 88°F | 57°F | 2% | 1% | 12 h 40 min |
| September 11 | 88°F | 57°F | 2% | 1% | 12 h 40 min |
| September 12 | 88°F | 57°F | 2% | 1% | 12 h 40 min |
| September 13 | 88°F | 57°F | 2% | 1% | 12 h 30 min |
| September 14 | 88°F | 57°F | 2% | 1% | 12 h 30 min |
| September 15 | 87°F | 57°F | 2% | 1% | 12 h 30 min |
| September 16 | 87°F | 57°F | 2% | 1% | 12 h 30 min |
| September 17 | 87°F | 57°F | 3% | 1% | 12 h 20 min |
| September 18 | 87°F | 57°F | 3% | 1% | 12 h 20 min |
| September 19 | 87°F | 56°F | 3% | 1% | 12 h 20 min |
| September 20 | 86°F | 56°F | 3% | 1% | 12 h 20 min |
| September 21 | 86°F | 56°F | 3% | 2% | 12 h 10 min |
| September 22 | 86°F | 56°F | 3% | 2% | 12 h 10 min |
| September 23 | 86°F | 56°F | 4% | 2% | 12 h 10 min |
| September 24 | 85°F | 56°F | 4% | 2% | 12 h 10 min |
| September 25 | 85°F | 56°F | 4% | 2% | 12 h 10 min |
| September 26 | 85°F | 56°F | 4% | 2% | 12 h |
| September 27 | 85°F | 56°F | 4% | 2% | 12 h |
| September 28 | 84°F | 55°F | 4% | 2% | 12 h |
| September 29 | 84°F | 55°F | 5% | 3% | 12 h |
| September 30 | 84°F | 55°F | 5% | 3% | 11 h 50 min |
- Normal high
- 87°FSeptember average
- Normal low
- 57°FSeptember average
- Precipitation
- 0.08 inmonth total
- Days with precipitation
- 10.01 inch or more
- Days at 90°F or more
- 12
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 30
- Days at 80°F or more
- 24
- Sunshine
- 93%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00042934; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Fairfield in September?
On a given September day the chance of 0.01 inch or more is 3% on average, highest around September 30 (5%). In all, 0.08 in falls on 1 days of a normal September.
In a normal September in Fairfield, 12 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00042934.
What are the records for September in Fairfield?
The warmest September temperature on this station's record (since 1950) is 114°F, on September 6, 2022; the coldest is 39°F, on September 20, 1986. The wettest September brought 2.49 in (1959).
The September mean against the 1991-2020 normal of 71.7°F: 2021 73.0°F (+1.3), 2022 75.3°F (+3.6), 2023 69.2°F (−2.5), 2024 73.3°F (+1.6), 2025 73.5°F (+1.8), 2026 71.2°F (−0.5). 4 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 73.0°F | +1.3°F | 0.00 in |
| 2022 | 75.3°F | +3.6°F | 0.43 in |
| 2023 | 69.2°F | −2.5°F | 0.20 in |
| 2024 | 73.3°F | +1.6°F | 0.00 in |
| 2025 | 73.5°F | +1.8°F | 0.14 in |
| 2026 | 71.2°F | −0.5°F | 0.00 in |
Source: records: ACIS, station USC00042934; recent months: ACIS, station USC00042934. Records and recent months use complete months only.
How does September in Fairfield 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; Fairfield's is 87°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Fairfield in August89°F by day, 58°F at night
- Fairfield in October78°F by day, 52°F at night
- Fairfield through the yearEvery month, frost dates, records and recent years
- California in SeptemberThe statewide normal and the warmest and coolest places
- Brawley: California's warmest Septembernormal high 104°F