Santa Rosa has a warm-summer Mediterranean climate with cool, wet winters and warm, dry summers.
In the summer, fog and low overcast often move in from the Pacific Ocean during the late evenings or early mornings. It usually clears up to warm, sunny weather by late morning or noon before returning but will occasionally linger all day.
Pro Tip: Season Suite
On average there are 256 sunny days in Santa Rosa, well over the US average of 205. During “bud break” season (spring) rain starts to disappear, and temperatures range from a low of 42F (5.5C) to an average high during the day of 70F (21C). In the “event” season (summer) there is almost no rain and the average low is 51F (10.5C) and the average high is 83F (28C). During “crush” (fall) the average low is 48F (9C) while the average high is 80F (26.7 C). In the “value” season of winter, there are far fewer crowds, the rain is the heaviest, and the temperatures range on average from a low of 38F (3.3C) to a high of around 60F (15.5C).
While the dress in Sonoma County is fashionable, we are also casual. The sight of a full suit and tie is rarer than the 100-point wine. Most daily activities can be done in shorts, skirts, jeans, and flip-flops. While our events cover all ranges, the most common fashion style is either resort or business casual.
Pro Tip: Dress in Layers
The key to Sonoma County can be summed up in three words: layers, layers, layers. Dressing for what the grapes love is key. The grapes love warm days and cool nights and that is what we have. The size of Sonoma County also matters. Covering multiple wine AVA and regions (microclimates anyone), the weather can catch you by surprise and layering is a way to enjoy the cooler coast and warmer inland areas all on the same day. A key tip is bringing a sweater or jacket if you are heading into any wine caves as our wineries love aging their wine in caves because the average cave temperature stays constant at around 55F-60F (13C-15.5C).
The best advice on wine tasting is to either bring a designated driver or take a tour. Wine tours can be customized for just two or can be coordinated for larger groups. Once you map out the wineries and timing, leave extra time for meals and just lingering. Many times, people get excited and try to cram in too many wineries in one day. Trust us, your pallet will get tired plus you will find at least one winery you just love, and now is the time to stay, linger and just enjoy wine country.
Pro Tip: The Coastal Climate
At the Sonoma Coastline, prevailing wind currents create a strong upwelling of cooler subsurface ocean waters. When the marine layer meets with the colder waters along the Sonoma Coast, it cools to its dewpoint, and small particles of water droplets—fog—is formed. The temperature difference between the chilly coastal waters and the warm inland valleys creates a pressure gradient that turns the northwesterly flow to a westerly direction at the coastline, driving the cool marine layer and its clouds onshore through and over any gaps in the coastal mountain ranges during the warmer months.