Climate averages 1991–2020
Fairfield weather
in October.
A warm, fairly dry month: the joint 5th warmest and the 6th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
October is a warm month in Fairfield: daytime highs average 24.5°C and nights cool to about 12.5°C. By daytime temperature it is the joint 5th warmest of the 12 months.
Expect about 24 mm of rain on roughly 3 days, which makes October a fairly dry month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 14 min on an average October day.
The nearest other city in this atlas is Vacaville (13 km away). In October its highs average 25.2°C, 0.7°C warmer than Fairfield, with 24 mm of rain.
Among the 498 cities listed in the United States, Fairfield ranks joint 179th of 498 for the warmest October highs and joint 111th of 498 for the driest October (rainfall, lowest first). The mean October high of those 498 cities is 21.4°C; Fairfield is 3.2°C warmer than that mean.
From October to November, average highs fall by 6.7°C to 17.8°C, and monthly rainfall rises from 24 mm to 50 mm.
The annual picture
October in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Fairfield climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 13.7°C5.4°C | 5.4°C | 109 | 9.2 | 9.810 h |
| February | 15.5°C6.4°C | 6.4°C | 108 | 9.1 | 10.711 h |
| March | 17.9°C7.7°C | 7.7°C | 79 | 8.2 | 11.912 h |
| April | 20.7°C9.1°C | 9.1°C | 34 | 4.8 | 13.213 h |
| May | 24.5°C11.4°C | 11.4°C | 18 | 3.2 | 14.214 h |
| June | 28.4°C13.5°C | 13.5°C | 4.2 | 0.9 | 14.815 h |
| July | 29.9°C14.3°C | 14.3°C | 0.4 | 0.1 | 14.515 h |
| August | 29.8°C14.6°C | 14.6°C | 1.0 | 0.2 | 13.614 h |
| September | 28.9°C14.3°C | 14.3°C | 1.5 | 0.4 | 12.512 h |
| October, selected | 24.5°C12.5°C | 12.5°C | 24 | 2.7 | 11.211 h |
| November | 17.8°C8.7°C | 8.7°C | 50 | 5.8 | 10.110 h |
| December | 13.6°C5.8°C | 5.8°C | 101 | 9.0 | 9.610 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
October in nearby cities
- Vacaville in OctoberUnited States · 13 kmHigh 25.2°C · Low 12.9°C · 24 mm rain
- Napa in OctoberUnited States · 22 kmHigh 25.1°C · Low 12.6°C · 26 mm rain
- Vallejo in OctoberUnited States · 25 kmHigh 24.4°C · Low 11.9°C · 23 mm rain
- Concord (California), United States in OctoberUnited States · 30 kmHigh 24.3°C · Low 12.4°C · 21 mm rain
- Antioch in OctoberUnited States · 34 kmHigh 24.4°C · Low 12.8°C · 22 mm rain
- Berkeley in OctoberUnited States · 47 kmHigh 23.2°C · Low 11.7°C · 21 mm rain
- San Ramon in OctoberUnited States · 52 kmHigh 23.6°C · Low 12.0°C · 21 mm rain
- Oakland in OctoberUnited States · 53 kmHigh 23.2°C · Low 12.1°C · 21 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Fairfield) is explained once on the Fairfield year overview and on the Sources, method and limits page.
Vacaville lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.