Sonoma County Climate
Sonoma County, California
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
57.9°F
Annual Precip
36.6"
Annual Snowfall
0.0"
Extreme Heat Days
32
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
9b
Minimum winter temperature range for plant survival
3,146
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Sonoma County
Climate Verdict
Sonoma County has a mild, with an average annual temperature of 57.9°F, moderate rainfall of 36.6 inches per year, occasional hot days — 31.5 per year above 90°F, virtually no measurable snowfall. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are mild, with January temperatures averaging 48.7°F. summers are pleasantly cool with July averaging 66.2°F. The climate is remarkably stable year-round, with only a 18°F difference between January and July. December is typically the coldest month and August the warmest.
Outdoor & Gardening Guidance
The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.
Regional Context
Sonoma County closely matches the California statewide average temperature of 58.7°F, it is also noticeably wetter, receiving 10.8 inches more precipitation than the state average, the county experiences 27.170924962933874 fewer extreme heat days than the state average.
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
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.