While the environment in San Francisco in August features cold murky mornings and nights, a short drive to the Napa Valley will compensate you with ordinary daytime temperatures in the 90’s and very gentle nights.
The regular temperature during August in Calistoga is 72 degrees, with an ordinary high of 91, and a normal low of 52 degrees. The run-of-the-mill precipitation in Calistoga for August is 0.1 inches, with the last August precipitation in 1997. Visitors from the East will rapidly see that the air is dry and occasionally sodden.
In the town of Napa, the regular August temperature is 68 degrees, while the ordinary high is 81 degrees, and the run-of-the-mill low is 54. The run-of-the-mill precipitation for August is 0.1 inches. Temperatures and precipitation in Yountville and Oakville, a couple of miles north of Napa, would be for the most part identical to those in Napa.