Weather & Climate in Bloomfield, CA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Bloomfield enjoys a temperate climate with an average annual temperature of 58°F (15°C). Winters average 48°F in January while summers reach 68°F in July. Annual precipitation totals 33.8 inches. Air quality is rated Good with a median AQI of 19 / among the cleanest air in the country. 95% of days have good air quality. The city sits at an elevation of 180 feet.
Temperature
48°F Jan (9°C)
68°F Jul (20°C)
| Annual Average | 58.1°F |
| 8% above US avg | |
| January Average | 48°F (9°C) |
| July Average | 68°F (20°C) |
Geography
| Elevation | 180 ft (55 m) |
| Area | 8.1 sq mi (21.1 km²) |
| Population Density | 36/sq mi |
| Coordinates | 38.3221°N, 122.8345°W |
| Timezone | America/Los_Angeles |
| County | Sonoma County County |
| Nearest Airport | Metro Oakland International (OAK) 53 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 19.0 |
| Rating | Good |
| Good Days % | 95.1% |
| Unhealthy Days | 0 |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 99.1 / 100 |
| Social Vulnerability | 29.8 / 100 |
| Community Resilience | 66.2 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively High |
| Wildfire | Relatively High |
| Flood | Relatively High |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very Low |
| Lightning | Relatively Moderate |
| Drought | Relatively High |
| Cold Wave | No Rating |
| Landslide | Relatively High |
| Coastal Flood | Relatively Moderate |
| Tsunami | Very Low |
| Volcano | Relatively Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
4,100 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M6.0.
| Aug 24, 2014 | The 2014 South Napa, California Earthquake | M6.0 | 47 km | 11 km |
| Aug 10, 2016 | 20 km NNE of Upper Lake, California | M5.1 | 112 km | 14 km |
| Sep 3, 2000 | 5 km WSW of Yountville, California | M4.9 | 37 km | 9 km |
| Sep 4, 1995 | 13 km SW of Middletown, California | M4.8 | 41 km | 7 km |
| Apr 18, 2007 | 15 km N of Potter Valley, California | M4.8 | 129 km | 5 km |
| May 12, 2006 | 7 km W of Cobb, California | M4.7 | 55 km | 4 km |
| May 21, 1996 | 8 km ESE of East Foothills, California | M4.7 | 145 km | 8 km |
| Jan 2, 2025 | 4 km NW of Cobb, CA | M4.7 | 59 km | 1 km |
| Aug 18, 1999 | 0 km S of Bolinas, California | M4.6 | 48 km | 8 km |
| Jan 11, 2000 | 6 km N of Geyserville, California | M4.6 | 50 km | 6 km |
| Feb 18, 2004 | 4 km WNW of Cobb, California | M4.6 | 58 km | 3 km |
| Jan 12, 2014 | 8 km W of Cobb, California | M4.5 | 55 km | 2 km |
| Sep 25, 2012 | 3 km N of Talmage, California | M4.5 | 98 km | 11 km |
| Aug 3, 2006 | 5 km W of Glen Ellen, California | M4.5 | 22 km | 9 km |
| Jun 8, 2024 | 7 km NW of The Geysers, CA | M4.5 | 55 km | 4 km |
| Sep 19, 1992 | 7 km NW of Cobb, California | M4.5 | 60 km | 3 km |
| Apr 24, 2007 | 7 km WSW of Cobb, California | M4.5 | 53 km | 2 km |
| Jun 3, 2023 | 2km NW of The Geysers, CA | M4.5 | 53 km | 4 km |
| Mar 14, 2013 | 5 km W of Cobb, California | M4.4 | 55 km | 1 km |
| Mar 1, 2011 | 8 km W of Cobb, California | M4.4 | 55 km | 2 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
30 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 1 injury.
| Date | Rating | Distance | Path | Fatalities |
| Jun 1, 1958 | EF2 | 14 km | 15.0 mi | 0 |
| Mar 18, 2011 | EF1 | 18 km | 0.1 mi | 0 |
| Mar 20, 2005 | EF1 | 83 km | 3.0 mi | 0 |
| Jan 27, 2005 | EF1 | 41 km | 0.5 mi | 0 |
| Dec 5, 1998 | EF1 | 18 km | 1.5 mi | 0 |
| Dec 23, 1996 | EF1 | 12 km | 6.0 mi | 0 |
| Feb 22, 1996 | EF1 | 27 km | 1.0 mi | 0 |
| Dec 2, 1992 | EF1 | 25 km | 3.0 mi | 0 |
| Dec 2, 1992 | EF1 | 9 km | 1.0 mi | 0 |
| Dec 2, 1992 | EF1 | 10 km | 7.5 mi | 0 |
| Feb 27, 1983 | EF1 | 18 km | 0.8 mi | 0 |
| Nov 10, 1964 | EF1 | 23 km | 1.0 mi | 0 |
| Feb 17, 1959 | EF1 | 42 km | 0.5 mi | 0 |
| Apr 1, 1958 | EF1 | 89 km | 0.2 mi | 0 |
| Sep 28, 2019 | EF0 | 99 km | 1.7 mi | 0 |
| Apr 27, 2016 | EF0 | 66 km | 0.2 mi | 0 |
| Apr 7, 2011 | EF0 | 63 km | 0.1 mi | 0 |
| Mar 20, 2005 | EF0 | 94 km | 1.2 mi | 0 |
| Jan 11, 2005 | EF0 | 75 km | 0.1 mi | 0 |
| Dec 29, 2004 | EF0 | 18 km | 0.2 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Tsunami History
4 tsunamis recorded within 500 km. Highest wave on record: 4.5 m (15 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1868 | N. CALIFORNIA | Eruption + Earthquake | 4.5 m | 30 | 95 km |
| 1856 | N. CALIFORNIA | Eruption + Earthquake | 0.6 m | - | 103 km |
| 1906 | N. CALIFORNIA | Eruption + Earthquake | 0.1 m | - | 75 km |
| 1865 | N. CALIFORNIA | Eruption + Earthquake | - | - | 149 km |
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
1 volcano within 200 km. Closest: Clear Lake (72 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Clear Lake | Volcanic field | 1,439 m (4,721 ft) | Unknown | 72 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: HENNESSEY (314,241 acres, 2020).
| Year | Name | Acres Burned | Distance |
| 2020 | HENNESSEY | 314,241 | 59 km |
| 2015 | ROCKY | 96,125 | 73 km |
| 2018 | COUNTY | 92,450 | 72 km |
| 1996 | FORK | 83,209 | 98 km |
| 2019 | KINCADE | 77,780 | 39 km |
| 2015 | VALLEY | 77,507 | 55 km |
| 2020 | GLASS | 68,020 | 36 km |
| 2017 | NUNS | 56,883 | 29 km |
| 2020 | WALLBRIDGE | 55,194 | 36 km |
| 2017 | ATLAS | 51,664 | 52 km |
| 2018 | RIVER | 48,920 | 83 km |
| 2004 | RUMSEY | 39,335 | 69 km |
| 1999 | SIXTEEN | 37,162 | 69 km |
| 2017 | TUBBS | 36,981 | 31 km |
| 1988 | MILLER | 35,750 | 66 km |
| 2017 | 18,691 | 50 km | |
| 2012 | SIXTEEN COMPLEX | 18,191 | 89 km |
| 2006 | ZAM ASSIST | 14,404 | 94 km |
| 2008 | WALKER | 12,441 | 88 km |
| 2004 | GEYSERS | 12,075 | 46 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 48°F (9°C) | 6.7 in | |
| February | 51°F (10°C) | 6.7 in | |
| March | 53°F (12°C) | 4.6 in | |
| April | 56°F (13°C) | 2.1 in | |
| May | 61°F (16°C) | 1.3 in | |
| June | 66°F (19°C) | 0.3 in | |
| July | 68°F (20°C) | 0.0 in | Driest |
| August | 68°F (20°C) | 0.1 in | Warmest |
| September | 67°F (19°C) | 0.1 in | |
| October | 61°F (16°C) | 1.7 in | |
| November | 53°F (12°C) | 3.6 in | |
| December | 47°F (8°C) | 6.8 in | Coldest, Wettest |
Bloomfield has a seasonal temperature swing of 21°F / from 47°F in December to 68°F in August. Total annual precipitation is 33.8 inches, with December being the wettest month (6.8") and July the driest (0.0").