California, United States of America · population 80,434 · 390 weather stations within 200 km · records 1837 to 2025
Napa has an average annual daytime high of 21.5°C, based on the 1951 to 1980 baseline. Its warmest month is July, when highs typically reach 29.9°C, and its coldest is January, with overnight lows near 2.4°C.
These figures reflect annual averages, not single-day records. Daily observations are outside this dataset's precision.
Since 1900, Napa's average temperature has risen by +1.5°C. Compared to the earliest station records that begin in 1837, warming totals +1.8°C.
20-year smoothed annual temperature reconstructed from station anomalies. Dashed line: 1951–1980 baseline.
Daytime highs sit within a comfortable 15°C to 26°C range.
Napa's average annual daytime high is 21.5°C, based on the 1951 to 1980 baseline period. The warmest month is July, with highs averaging 29.9°C, and the coldest is January, with lows averaging 2.4°C.
July is the warmest month in Napa, with typical daytime highs of 29.9°C.
2014 is the hottest year on record for Napa, running +1.9°C above the 1951 to 1980 baseline.
Yes. Since 1900, Napa has warmed by roughly +1.5°C.
February to November typically offers the most comfortable daytime highs, in the 15°C to 26°C range.
Baseline period 1951 to 1980. Monthly averages are the mean of station observations weighted by proximity. Warming trend is the 20-year smoothed anomaly against that baseline.