How extreme does Napa's weather get?

The hottest, coldest, wettest and snowiest days Napa has recorded — the outer limits of what its weather can do, and how far they sit beyond a normal day.

Based on 50+ years of daily weather observations (1971–present), from the Sonoma station 15 km away. Updated through March 2026 — an all-time extreme only changes when a more extreme day actually occurs, so some dates are old. That is normal, not stale data.

The four kinds of extreme

The hottest, coldest, wettest and snowiest single days Napa has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day

116°F Jul 13, 1972

That is about 30°F hotter than a normal July afternoon in Napa (typical high near 86°F).

The three most extreme on record

1 116°F Jul 13, 1972

2 114°F Jul 14, 1972

3 112°F Jul 15, 1972

❄️ Coldest night

13°F Dec 22, 1990

About 25°F colder than a normal December night in Napa (typical low near 38°F).

The three most extreme on record

1 13°F Dec 22, 1990

2 15°F Apr 1, 1983

3 15°F Dec 23, 1990

🌧️ Most rain in one day

20.00 in Jul 7, 1982

The three most extreme on record

1 20.00 in Jul 7, 1982

2 6.75 in Jan 4, 1982

3 5.75 in Jan 11, 1979

How hot and cold it gets, month by month

The shaded band is the normal range of daily temperatures for each month. The dots show the most extreme it has ever been — so you can see how far beyond a normal day the records really sit.

normal range of daily temperatureshottest ever recordedcoldest ever recorded

Napa's record heat sits well above even a hot day for the season — July's 116°F is about 30°F beyond a normal hot afternoon. Its record cold is just as far below a normal winter night — the dots mark how rare each extreme really is.

In plain terms

In a normal year, Napa's warmest days reach the mid-80s°F and its coldest nights drop to the high 30s°F. But across the record it has gone as high as 116°F and as low as 13°F. A single day has delivered over 20 inches of rain. Those are the outer edges worth knowing if you are moving here, planning a trip, or thinking about a house.

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Berkeley (NOAA GHCN station USC00040693), about 47 km from the city centre.

How we build these numbers →

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