Climate averages 1991–2020
Fairfield weather
in July.
A hot, very dry month: the warmest and the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
July is a hot month in Fairfield: daytime highs average 29.9°C and nights cool to about 14.3°C. By daytime temperature it is the warmest month of the year.
Rain is very rare: less than 1 mm falls in a typical July (the driest month of the year). Daylight, from sunrise to sunset, lasts about 14 h 33 min on an average July day.
The nearest other city in this atlas is Vacaville (13 km away). In July its highs average 32.4°C, 2.5°C warmer than Fairfield, with almost no rain (under 1 mm).
Among the 498 cities listed in the United States, Fairfield ranks joint 268th of 498 for the warmest July highs and joint 9th of 498 for the driest July (rainfall, lowest first). The mean July high of those 498 cities is 30.3°C; Fairfield is 0.4°C cooler than that mean.
From July to August, average highs fall by 0.1°C to 29.8°C, and monthly rainfall rises from under 1 mm to 1.0 mm.
The annual picture
July 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, selected | 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 | 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
July in nearby cities
- Vacaville in JulyUnited States · 13 kmHigh 32.4°C · Low 15.7°C · 0.4 mm rain
- Napa in JulyUnited States · 22 kmHigh 30.7°C · Low 14.7°C · 0.4 mm rain
- Vallejo in JulyUnited States · 25 kmHigh 28.5°C · Low 13.4°C · 0.5 mm rain
- Concord (California), United States in JulyUnited States · 30 kmHigh 28.8°C · Low 14.1°C · 0.5 mm rain
- Antioch in JulyUnited States · 34 kmHigh 30.2°C · Low 15.1°C · 0.4 mm rain
- Berkeley in JulyUnited States · 47 kmHigh 25.9°C · Low 13.1°C · 0.4 mm rain
- San Ramon in JulyUnited States · 52 kmHigh 28.1°C · Low 14.4°C · 0.7 mm rain
- Oakland in JulyUnited States · 53 kmHigh 26.0°C · Low 13.7°C · 0.4 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.