Sonoma County Climate

Sonoma County, California

JanFebMarAprMayJunJulAugSepOctNovDec57.9°AVG °F

Avg Annual Temp

57.9°F

Annual Precip

36.6"

Annual Snowfall

0.0"

Extreme Heat Days

31.5

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
7.0"
7.0"
4.9"
2.4"
1.4"
0.4"
0.0"
0.1"
0.1"
1.9"
3.9"
7.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Seasonal Overview

Comfort ZoneSpring53°60°8.7"Summer64°67°0.5"Fall54°66°5.9"Winter48°51°21.5"20°40°60°80°100°

National Comparison

Warmer than 62% of US counties
Wetter than 37% of US counties
More seasonal variation than 1% of US counties

Climate Profile

About Sonoma County Weather

Warmer than the national median

Sonoma County’s 57.9°F average temperature sits well above the U.S. national median, characterizing its stable Mediterranean climate. This temperate environment avoids the harsh winter extremes found in much of the country. It offers a mild, consistent warmth that defines the region.

Mirroring the California average

At 57.9°F, Sonoma is nearly identical to the California state average of 58.7°F. While many inland counties bake, Sonoma remains one of the state's more moderate locales. It serves as a benchmark for the balanced coastal-inland weather profile.

A lush, wet neighbor

The county receives 36.6 inches of rain annually, far exceeding the state average of 25.8 inches. This makes it significantly wetter than Central Valley neighbors like Stanislaus, which sees only 12.3 inches. The moisture supports the region's famous greenery and agricultural diversity.

Mild winters and sunny summers

Summer temperatures average 65.7°F, but the county still faces 32 extreme heat days over 90°F annually. Winters are gentle at 49.3°F with no recorded snowfall. This combination allows for year-round outdoor activity without specialized winter gear.

Prepare for wet winters

Residents should invest in high-quality rain gear to handle the 36.6 inches of annual precipitation. While summers are moderate, air conditioning is necessary to manage the month’s worth of extreme heat days. Home maintenance should prioritize drainage to handle the heavy seasonal rainfall.

Frequently Asked Questions

What is the average temperature in Sonoma County?
The average annual temperature in Sonoma County, CA is 57.9°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Sonoma County get?
Sonoma County receives an average of 36.6 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Sonoma County?
Sonoma County receives little to no measurable snowfall in a typical year, based on NOAA 30-year climate normals.
How hot does Sonoma County get in summer?
The average summer temperature (June-August) in Sonoma County is 65.7°F. The county experiences an average of 31.5 days per year above 90°F.
How cold are winters in Sonoma County?
The average winter temperature (December-February) in Sonoma County is 49.3°F. January, typically the coldest month, averages 48.7°F.

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Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.

Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

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