Mountain View has the mild, dry climate of the South Bay — warm summers, cool winters, and almost no rain from May through October. Summer temperatures hover around 25°C (77°F) with cool evenings; winter rarely drops below 5°C (41°F), and most winter days are clear.
The main outdoor events season runs spring through autumn. Shoreline Amphitheatre has concerts from May to October, and the Shoreline sailing school operates over the same period. The Mountain View Art & Wine Festival in September shuts down Castro Street for two days and draws large crowds — if you're not into that kind of thing, it's a good weekend to avoid downtown.
Spring and early autumn are the most comfortable for outdoor activities: the bay winds are reliable enough for windsurfing and kiteboarding at Shoreline Lake without the summer heat. The farmers market on Castro Street runs year-round on Sunday mornings.