August weather in Napa, CA
The average temperature in Napa in August is 69.6°F (55.5°F–83.7°F). Average precipitation: 0.06 inches.
August is a summer month in Napa, and is warmer than the annual average of 60.3°F. Daily temperatures swing about 28.2°F between overnight low and afternoon high. Expect about 0 days with precipitation. Daylight averages about 13h 29m. For travel, August is a comfortable month to visit.
Avg High
83.7°F
Avg Low
55.5°F
Precipitation
0.06 in
Daylight
13h 29m
August records in Napa
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 109.9°F (1900) | 44.1°F (1932) | 0.27 in (2022) |
| August 2 | 105.1°F (1946) | 44.1°F (1918) | 0.00 in (1893) |
| August 3 | 105.1°F (1998) | 42.1°F (1932) | 0.00 in (1893) |
| August 4 | 106.0°F (1998) | 46.0°F (1918) | 0.00 in (1893) |
| August 5 | 102.9°F (1998) | 45.0°F (1950) | 0.05 in (2014) |
| August 6 | 102.0°F (1913) | 42.1°F (1917) | 0.00 in (1893) |
| August 7 | 102.0°F (1984) | 44.1°F (1932) | 0.00 in (1893) |
| August 8 | 100.0°F (1984) | 39.9°F (1932) | 0.00 in (1893) |
| August 9 | 104.0°F (1898) | 39.0°F (1932) | 0.11 in (1962) |
| August 10 | 102.0°F (1940) | 39.9°F (1932) | 0.04 in (1936) |
| August 11 | 98.1°F (1998) | 42.1°F (1932) | 0.84 in (1965) |
| August 12 | 98.1°F (1998) | 42.1°F (1932) | 0.01 in (1965) |
| August 13 | 98.1°F (1998) | 41.0°F (1979) | 0.16 in (1991) |
| August 14 | 104.0°F (2020) | 46.0°F (1932) | 0.07 in (1976) |
| August 15 | 107.1°F (2020) | 43.0°F (1911) | 0.55 in (1976) |
| August 16 | 104.0°F (2015) | 43.0°F (1918) | 0.01 in (2020) |
| August 17 | 105.1°F (2015) | 37.0°F (1932) | 0.00 in (1893) |
| August 18 | 102.9°F (1934) | 45.0°F (1919) | 0.32 in (1976) |
| August 19 | 102.0°F (1950) | 44.1°F (1928) | 0.25 in (1976) |
| August 20 | 102.0°F (1950) | 45.0°F (1918) | 0.82 in (1997) |
| August 21 | 100.0°F (1969) | 44.1°F (1935) | 0.08 in (1968) |
| August 22 | 100.0°F (1910) | 44.1°F (1955) | 0.62 in (2003) |
| August 23 | 104.0°F (1931) | 41.0°F (1963) | 0.08 in (1904) |
| August 24 | 105.1°F (2010) | 42.1°F (1938) | 0.03 in (2024) |
| August 25 | 106.0°F (2010) | 44.1°F (1932) | 0.07 in (1926) |
| August 26 | 102.0°F (1894) | 41.0°F (1947) | 0.22 in (1954) |
| August 27 | 105.1°F (1944) | 42.1°F (1942) | 0.00 in (1893) |
| August 28 | 104.0°F (1944) | 42.1°F (1939) | 0.26 in (1923) |
| August 29 | 105.1°F (1968) | 45.0°F (1921) | 0.03 in (1953) |
| August 30 | 102.9°F (1968) | 37.9°F (1932) | 0.43 in (1896) |
| August 31 | 102.9°F (1902) | 42.1°F (1939) | 0.31 in (1984) |