The best time to visit Sunnyvale
Month-by-month climate averages for Sunnyvale, CA, so you can pick your dates on data rather than guesswork.
The most comfortable time to visit Sunnyvale is usually March, April, May and October, when daytime highs sit in the pleasant 60-78°F range and the heaviest January rain is behind you.
Sunnyvale is warmest in July (highs near 86°F) and coldest in December (lows around 42°F), with roughly 25 inches of precipitation across the year and January the wettest month. The sweet spot for most visitors is March, April, May and October.
These are long-run averages. For the actual days you are travelling, check the live Sunnyvale forecast - and note how much the models agree, because that tells you how much to trust it.
Sunnyvale weather by month
what to expect in Sunnyvale through the year, 1991-2020 averagesHere is Sunnyvale's typical weather in each month: the average daytime high and overnight low in °F, how each month feels, and the wettest month marked. Use it to plan any trip to Sunnyvale by season.