Napa County weather, town by town
11 places in Napa County, California, each with its own live forecast and radar, and where a station sits close enough, measured weather records.
A
C
D
M
N
O
R
S
Y
Not your town? Type it above, or pick it below.
Measured at the NOAA stations serving these towns, daily records 1893 to 2026. Station extremes, not official state records.
Napa County Weather Facts
Napa County has 11 places on myweatherrock (6 census-designated places, 5 cities), each with its own live forecast, hourly timeline, ten day outlook and radar. The hottest day in the station records is 118°F at Calistoga on September 7, 2022. The coldest night is 10°F at Calistoga on December 11, 1932. The wettest day brought 9.14 inches of rain at Calistoga on December 31, 1913. The biggest single-day snow measured 1.5 inches at Fairfield on December 27, 1988. Those are station measurements from NOAA's daily records, 1893 to 2026, not official state records. By area the largest place is Napa, about 18 square miles.
About Napa County weather
The map on the Now tab shows every Napa County town's current temperature from our own server, one dot per town. Tap any dot, or type a town above, for that town's full forecast.
What the weather is usually like
Across the 11 Napa County towns with station normals, the warmest month is August, when the day usually reaches 86°F, and the coldest is December, when the night usually falls to 39°F. December is the wettest, with rain on about 12 days. August afternoons run from about 79°F in American Canyon to 94°F in Moskowite Corner. December nights run from about 36°F in American Canyon to 40°F in Angwin.
Means of the 1991 to 2020 station normals serving these towns, as published by NOAA; each town's page carries its own.
Where these numbers come from
- Current conditions and forecast: NOAA forecast grids decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
- Records: computed by myweatherrock from NOAA GHCN-Daily station records at the stations serving these towns. Measurements, not estimates.
- Warnings and alerts: the National Weather Service, passed through unchanged.
Napa County weather records
Measured at the NOAA stations serving these towns, daily records 1893 to 2026. Station extremes, not official state records.
Common questions about Napa County weather
- What is the hottest temperature recorded at a Napa County station?
- 118°F at Calistoga on September 7, 2022, in the NOAA daily station records myweatherrock holds (1893 to 2026).
- What is the coldest temperature recorded at a Napa County station?
- 10°F at Calistoga on December 11, 1932.
- What is the most rain a Napa County station has measured in one day?
- 9.14 inches at Calistoga on December 31, 1913.
- What is the biggest one-day snowfall at a Napa County station?
- 1.5 inches at Fairfield on December 27, 1988.
- How many Napa County towns have a weather page here?
- 11: 6 census-designated places, 5 cities. Each page carries current conditions, the hourly timeline, the ten day outlook, radar, and where a station sits close enough, measured records.
- Where does the Napa County forecast come from?
- NOAA forecast grids (the National Weather Service digital forecast, the National Blend of Models, HRRR and GFS) decoded on our own server, corrected against the nearest reporting station and our own radar. Open-Meteo is consulted only as a fallback when our server is silent.
Live radar
Current details
Water
Next few days
Hourly forecast
10-day forecast
The Rocktionary: every weather term, explained by a rock
Rockreation: pick a game
All records live on this device. The rock keeps no receipts. You keep them.
The weather you throw is whatever is outside right now.
A new Rocktoid every midnight. The rock reads a lot.
The rock's instrument panel
Remote Rocks: station a rock anywhere you love
Put a rock in Mom's yard, the lake house, a kid's college town. Each one stands in that sky and reports it here. Tap a rock for its forecast; the pencil renames it.
Tap me on the shoulder turns on browser notifications: when a warning or watch lands on one of your rocks, you get a notification, as long as the site is open in a tab somewhere.
Remote Rocks live on this device. We do not track you, so a rock you station on your phone will not appear on your computer or tablet, and the other way around. That is the privacy working, not a bug. Forecasts and alerts travel from here straight to the weather services, same as always.
Settings
Build