Weather & Climate in Anchor Bay, CA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Anchor Bay enjoys a temperate climate with an average annual temperature of 60°F (15°C). Winters average 48°F in January while summers reach 75°F in July. Annual precipitation totals 34.8 inches. The area receives 2.5 inches of snow annually. 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 671 feet.
Temperature
48°F Jan (9°C)
75°F Jul (24°C)
| Annual Average | 59.8°F |
| 11% above US avg | |
| January Average | 48°F (9°C) |
| July Average | 75°F (24°C) |
Geography
| Elevation | 671 ft (205 m) |
| Area | 3.5 sq mi (9.1 km²) |
| Population Density | 219/sq mi |
| Coordinates | 38.8127°N, 123.5703°W |
| Timezone | America/Los_Angeles |
| County | Sonoma County County |
| Nearest Airport | San Francisco International (SFO) 105 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
3,430 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 | 128 km | 11 km |
| Aug 10, 2016 | 20 km NNE of Upper Lake, California | M5.1 | 88 km | 14 km |
| Sep 3, 2000 | 5 km WSW of Yountville, California | M4.9 | 112 km | 9 km |
| Sep 4, 1995 | 13 km SW of Middletown, California | M4.8 | 73 km | 7 km |
| Apr 18, 2007 | 15 km N of Potter Valley, California | M4.8 | 83 km | 5 km |
| May 12, 2006 | 7 km W of Cobb, California | M4.7 | 66 km | 4 km |
| Jan 2, 2025 | 4 km NW of Cobb, CA | M4.7 | 71 km | 1 km |
| Aug 18, 1999 | 0 km S of Bolinas, California | M4.6 | 127 km | 8 km |
| Jan 11, 2000 | 6 km N of Geyserville, California | M4.6 | 57 km | 6 km |
| Feb 18, 2004 | 4 km WNW of Cobb, California | M4.6 | 70 km | 3 km |
| Jan 12, 2014 | 8 km W of Cobb, California | M4.5 | 65 km | 2 km |
| Sep 25, 2012 | 3 km N of Talmage, California | M4.5 | 53 km | 11 km |
| Aug 3, 2006 | 5 km W of Glen Ellen, California | M4.5 | 99 km | 9 km |
| Jun 8, 2024 | 7 km NW of The Geysers, CA | M4.5 | 65 km | 4 km |
| Sep 19, 1992 | 7 km NW of Cobb, California | M4.5 | 68 km | 3 km |
| Apr 24, 2007 | 7 km WSW of Cobb, California | M4.5 | 67 km | 2 km |
| Jun 3, 2023 | 2km NW of The Geysers, CA | M4.5 | 69 km | 4 km |
| Mar 14, 2013 | 5 km W of Cobb, California | M4.4 | 68 km | 1 km |
| Mar 1, 2011 | 8 km W of Cobb, California | M4.4 | 65 km | 2 km |
| Apr 12, 2023 | 7km WNW of Cobb, CA | M4.4 | 66 km | 2 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
16 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2.
| Date | Rating | Distance | Path | Fatalities |
| Jun 1, 1958 | EF2 | 78 km | 15.0 mi | 0 |
| Mar 18, 2011 | EF1 | 85 km | 0.1 mi | 0 |
| Jan 27, 2005 | EF1 | 45 km | 0.5 mi | 0 |
| Dec 5, 1998 | EF1 | 86 km | 1.5 mi | 0 |
| Dec 5, 1998 | EF1 | 71 km | 1.7 mi | 0 |
| Dec 23, 1996 | EF1 | 84 km | 6.0 mi | 0 |
| Feb 22, 1996 | EF1 | 79 km | 1.0 mi | 0 |
| Dec 2, 1992 | EF1 | 74 km | 7.5 mi | 0 |
| Dec 2, 1992 | EF1 | 79 km | 1.0 mi | 0 |
| Dec 2, 1992 | EF1 | 71 km | 3.0 mi | 0 |
| Feb 27, 1983 | EF1 | 86 km | 0.8 mi | 0 |
| Nov 10, 1964 | EF1 | 74 km | 1.0 mi | 0 |
| Feb 17, 1959 | EF1 | 43 km | 0.5 mi | 0 |
| Dec 29, 2004 | EF0 | 86 km | 0.2 mi | 0 |
| Dec 11, 1983 | EF0 | 48 km | 2.0 mi | 0 |
| Feb 3, 1958 | EF0 | 8 km | 0.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Nearby Volcanoes
1 volcano within 200 km. Closest: Clear Lake (71 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Clear Lake | Volcanic field | 1,439 m (4,721 ft) | Unknown | 71 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: RANCH (427,048 acres, 2018).
| Year | Name | Acres Burned | Distance |
| 2018 | RANCH | 427,048 | 85 km |
| 2015 | ROCKY | 96,125 | 98 km |
| 1996 | FORK | 83,209 | 84 km |
| 2019 | KINCADE | 77,780 | 71 km |
| 2015 | VALLEY | 77,507 | 83 km |
| 2020 | GLASS | 68,020 | 93 km |
| 2020 | WALLBRIDGE | 55,194 | 53 km |
| 1987 | MENDENHALL | 54,162 | 93 km |
| 2018 | RIVER | 48,920 | 55 km |
| 2017 | TUBBS | 36,981 | 82 km |
| 2017 | REDWOOD VALLEY INCIDENT | 36,545 | 66 km |
| 2012 | MILL | 29,924 | 99 km |
| 2001 | TROUGH | 25,270 | 99 km |
| 2017 | 18,691 | 60 km | |
| 1987 | FOUTS | 16,892 | 92 km |
| 2008 | WALKER | 12,441 | 99 km |
| 2004 | GEYSERS | 12,075 | 72 km |
| 1985 | UNNAMED | 9,655 | 62 km |
| 2008 | MEU LIGHTNING COMPLEX (SUGARLOAF) | 8,344 | 22 km |
| 1988 | UNNAMED | 5,076 | 63 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 48°F (9°C) | 6.7 in | |
| February | 50°F (10°C) | 6.3 in | |
| March | 53°F (12°C) | 5.3 in | |
| April | 56°F (13°C) | 2.6 in | |
| May | 63°F (17°C) | 1.2 in | |
| June | 69°F (21°C) | 0.3 in | |
| July | 75°F (24°C) | 0.0 in | Warmest, Driest |
| August | 74°F (23°C) | 0.1 in | |
| September | 70°F (21°C) | 0.2 in | |
| October | 62°F (17°C) | 1.8 in | |
| November | 52°F (11°C) | 3.5 in | |
| December | 46°F (8°C) | 6.9 in | Coldest, Wettest |
Anchor Bay has a seasonal temperature swing of 29°F / from 46°F in December to 75°F in July. Total annual precipitation is 34.8 inches, with December being the wettest month (6.9") and July the driest (0.0").