Santa Rosa CA average weather reflects the mild Mediterranean climate typical of Sonoma County. Residents and visitors can expect cool, rainy winters and warm, dry summers with moderate coastal influence year round.
This overview frames what to expect from temperature, rain, and fog so you can plan activities, commutes, and outdoor events around local patterns.
| Season | Average High | Average Low | Average Rainfall |
|---|---|---|---|
| Winter (Dec Feb) | 58 62°F | 42 46°F | 5 7 inches |
| Spring (Mar May) | 62 70°F | 46 52°F | 2 4 inches |
| Summer (Jun Aug) | 78 84°F | 52 56°F | 0 0.2 inches |
| Fall (Sep Nov) | 78 80°F | 50 54°F | 1 3 inches |
Seasonal Temperature Patterns in Santa Rosa
Santa Rosa experiences gentle seasonal temperature shifts rather than extreme swings. Winter highs usually stay in the upper 50s to low 60s, while summer highs commonly reach the upper 70s to mid 80s. Nighttime lows remain moderate year round, reducing the need for heavy heating or constant air conditioning.
The gradual transition from spring through fall allows comfortable outdoor living for much of the year. Daytime warmth in summer is often balanced by cool evening breezes, especially near the coast and in neighborhoods closer to Sonoma Creek. Understanding these patterns helps you choose the right clothing, schedule outdoor plans, and manage home energy use efficiently.
Rain, Fog, and Coastal Influence
Rainfall in Santa Rosa follows a distinct wet season from late fall to early spring, driven by Pacific storm systems. Most days during summer and early fall are dry, with clear skies and low humidity. Fog and low clouds occasionally move inland through the Russian River valley, especially in late summer, keeping some areas cooler and slightly more humid.
The coastal influence moderates temperature extremes and supports vineyards, gardens, and urban trees. Wind speeds are generally light to moderate, with breezier conditions near open spaces and the western edges of the city. These weather traits contribute to Santa Rosa’s reputation as a pleasant place to live and visit across multiple seasons.
Outdoor Recreation and Daily Life
- Check weekly forecasts before scheduling hikes, farmers markets, or outdoor gatherings.
- Layer clothing to adapt to cool mornings, warm afternoons, and breezy evenings.
- Plan outdoor exercise and yard work for early summer or fall to avoid peak summer heat.
- Stay informed about air quality days, especially during fire season.
Planning Day to Day Around Local Weather
FAQ
Reader questions
How often do temperatures exceed 90°F in Santa Rosa each year?
Days above 90°F are relatively infrequent, usually occurring on just a handful of days during summer heat waves, most commonly in July and August.
What months have the highest chance of rain in Santa Rosa?
The highest chance of rain occurs between December and February, with January typically being the wettest month of the year.
Does Santa Rosa experience severe wind or storm events?
Severe wind events are uncommon, though winter storms can bring gusty conditions and brief power outages during the strongest rain events.
How does coastal fog affect summer evenings in Santa Rosa?
Coastal fog sometimes rolls in during late summer, keeping nighttime temperatures cooler and adding higher humidity to July and August evenings.