Current Conditions
70°F
Feels like 69°F
Clear
Clear Sky
As of Oct 12, 2026, 1:09 PM · Last checked Oct 12, 2026, 1:09 PM
Times shown in America/Los_Angeles. Some values may come from forecast models.
3 mph
WSW · Gusts 12 mph
43%
6.2 mi
29.88 inHg
Napa Valley reports clear as of Oct 12, 2026, 1:09 PM with temperatures near 70°F (21°C). Humidity is 43%, and winds are around 3 mph.
Check the forecast times and official local alerts before planning commuting, outdoor activities, or travel in Napa Valley.
The Napa Valley has a Mediterranean climate with dry, warm summers and mild, wet winters. At the Napa State Hospital station, the 1991-2020 reference averages range from a daily high of 59°F (15°C) in Dec to 84°F (29°C) in Sep. Monthly precipitation averages sum to 26.7 inches (677 mm) per year.
Winter is the rainy season, when atmospheric rivers can swell the Napa River and turn the hills green. Spring brings frost season; clear, chilly nights during vine bud break keep growers watching overnight lows. Summers are dry and warm, with marine fog spilling in most nights to cool the valley and mornings often starting gray before sunny afternoons. Fall is harvest time: warm days, occasional heat spikes, and by October the dry offshore wind events that drive the region's most dangerous fire weather.
The Napa Valley's summer diurnal swing can exceed 30-40°F between afternoon high and overnight low, driven by cool marine air and fog pulled in nightly from San Pablo Bay, a key reason the region's wine grapes ripen slowly and evenly.
Local Planning Guide
Spring frost nights during bud break, harvest-season heat spikes, October offshore-wind fire weather, and winter atmospheric rivers are the windows when Napa Valley forecasts need the closest watch.
Alerts here are highly localized: Red Flag Warnings, frost advisories, and flood watches can apply to one stretch of the valley and not another, and conditions shift with the terrain between Carneros and Calistoga.
Climate reference averages (1991-2020). Average daily high, average daily low, and monthly precipitation.
| Month | Avg High | Avg Low | Precipitation |
|---|---|---|---|
| Jan | 58.6°F | 40.1°F | 5.0 in |
| Feb | 63.2°F | 41.9°F | 5.1 in |
| Mar | 67.5°F | 43.6°F | 3.7 in |
| Apr | 72.1°F | 45.6°F | 1.7 in |
| May | 76.6°F | 49.9°F | 1.1 in |
| Jun | 82.3°F | 53.7°F | 0.3 in |
| Jul | 83.3°F | 55.5°F | 0.0 in |
| Aug | 83.7°F | 55.5°F | 0.1 in |
| Sep | 84.4°F | 53.4°F | 0.1 in |
| Oct | 78.1°F | 49.3°F | 1.3 in |
| Nov | 66.2°F | 43.6°F | 2.8 in |
| Dec | 58.5°F | 39.7°F | 5.5 in |
Climate data and sources. Verified against NOAA NCEI: NAPA STATE HOSPITAL, CA US (PDF) (USC00046074), 1991-2020. Values are rounded for display. Raw data (JSON). Climate averages are not a forecast and do not describe every neighborhood.
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Glossary
An atmospheric river is a long, narrow corridor of concentrated water vapor moving through the lower atmosphere, typically 250 to 375 miles wide and often more than 1,000 miles long.
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