In May, Napa typically sees daytime highs of 23.6°C and overnight lows around 8.3°C. Compared to the annual average high of 21.5°C, May runs +2.1°C.
May in Napa averages a daytime high of 23.6°C and an overnight low of 8.3°C.
May runs +2.1°C compared to Napa's annual average high of 21.5°C, ranking #6 of 12 months by warmth.
Plan for daytime highs near 23.6°C and cooler evenings around 8.3°C.