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Fairfield, California climate
Csa Hot-summer Mediterranean
Fairfield has a seasonal mild-temperate climate (Hot-summer Mediterranean, Köppen Csa). The hottest month is July with an average daily high near 35°C, while the coldest is December averaging around 3°C at night. Precipitation totals about 631 mm a year and is strongly seasonal — January alone averages 134 mm while July barely receives 0 mm.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsFairfield climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 14 | 17 | 20 | 23 | 27 | 32 | 35 | 34 | 33 | 27 | 19 | 14 |
| Avg temp (°C) | 9 | 11 | 13 | 15 | 19 | 23 | 25 | 24 | 23 | 18 | 12 | 9 |
| Avg low (°C) | 3 | 5 | 6 | 8 | 11 | 14 | 15 | 14 | 13 | 10 | 5 | 3 |
| Precipitation (mm) | 134 | 129 | 94 | 33 | 21 | 4 | 0 | 1 | 2 | 27 | 59 | 129 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 14 | 17 | 20 | 23 | 27 | 32 |
| Avg temp (°C) | 9 | 11 | 13 | 15 | 19 | 23 |
| Avg low (°C) | 3 | 5 | 6 | 8 | 11 | 14 |
| Precipitation (mm) | 134 | 129 | 94 | 33 | 21 | 4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 35 | 34 | 33 | 27 | 19 | 14 |
| Avg temp (°C) | 25 | 24 | 23 | 18 | 12 | 9 |
| Avg low (°C) | 15 | 14 | 13 | 10 | 5 | 3 |
| Precipitation (mm) | 0 | 1 | 2 | 27 | 59 | 129 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 10 | 9 | 9 | 5 | 3 | 0.9 | 0.1 | 0.2 | 0.9 | 3 | 8 | 10 |
| Days with high ≥ 32°C (days) | — | — | — | 1.0 | 5 | 15 | 23 | 22 | 16 | 4 | — | — |
| Days with low ≤ 0°C (days) | 7 | 3 | 0.4 | 0.1 | — | — | — | — | — | — | 2 | 8 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 10 | 9 | 9 | 5 | 3 | 0.9 |
| Days with high ≥ 32°C (days) | — | — | — | 1.0 | 5 | 15 |
| Days with low ≤ 0°C (days) | 7 | 3 | 0.4 | 0.1 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 0.1 | 0.2 | 0.9 | 3 | 8 | 10 |
| Days with high ≥ 32°C (days) | 23 | 22 | 16 | 4 | — | — |
| Days with low ≤ 0°C (days) | — | — | — | — | 2 | 8 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 60 | 55 | 51 | 44 | 35 | 22 | 14 | 15 | 18 | 31 | 47 | 59 |
| Clear days (≤ 30% cloud) | 7 | 8 | 11 | 13 | 17 | 22 | 27 | 26 | 23 | 19 | 11 | 8 |
| Partly cloudy days (30–70%) | 9 | 9 | 9 | 9 | 8 | 5 | 3 | 4 | 5 | 8 | 10 | 10 |
| Cloudy days (≥ 70%) | 15 | 11 | 11 | 8 | 6 | 3 | 1 | 1 | 2 | 4 | 9 | 13 |
| Relative humidity (%) | 82 | 81 | 79 | 73 | 65 | 53 | 48 | 48 | 45 | 50 | 66 | 77 |
| Wind speed (m/s) | 1.9 | 2.1 | 2.0 | 2.2 | 2.4 | 2.6 | 2.8 | 2.6 | 2.2 | 2.0 | 1.9 | 2.1 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 60 | 55 | 51 | 44 | 35 | 22 |
| Clear days (≤ 30% cloud) | 7 | 8 | 11 | 13 | 17 | 22 |
| Partly cloudy days (30–70%) | 9 | 9 | 9 | 9 | 8 | 5 |
| Cloudy days (≥ 70%) | 15 | 11 | 11 | 8 | 6 | 3 |
| Relative humidity (%) | 82 | 81 | 79 | 73 | 65 | 53 |
| Wind speed (m/s) | 1.9 | 2.1 | 2.0 | 2.2 | 2.4 | 2.6 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 14 | 15 | 18 | 31 | 47 | 59 |
| Clear days (≤ 30% cloud) | 27 | 26 | 23 | 19 | 11 | 8 |
| Partly cloudy days (30–70%) | 3 | 4 | 5 | 8 | 10 | 10 |
| Cloudy days (≥ 70%) | 1 | 1 | 2 | 4 | 9 | 13 |
| Relative humidity (%) | 48 | 48 | 45 | 50 | 66 | 77 |
| Wind speed (m/s) | 2.8 | 2.6 | 2.2 | 2.0 | 1.9 | 2.1 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Vacaville/nut Tree AP Asos (NOAA GHCN station USW00093241), about 16 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.