Climate Insights for Cupertino

The climate in Cupertino is temperate. The average annual temperature is 14°C and approximately 580mm of precipitation falls per year. January is the wettest month, receiving around 126mm of rainfall. Cupertino is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: September, August, October. The coldest months are February, December, January, when temperatures can drop to 9°C.

Cupertino sees moderate temperature variation throughout the year, ranging from 9°C to 23°C. September is the warmest month, though highs remain moderate at 23°C with a mean of 18°C. February is the coolest month, with minimum temperatures around 9°C and an average of 12°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between October and November, with a 3°C shift in average temperatures.

Cupertino is a relatively dry area, receiving approximately 580mm of precipitation annually, which averages out to around 48mm per month. The wettest month is January, averaging 126mm of rainfall. December and February also tend to see above-average precipitation. The driest month is August, with just 0mm. That's 125mm less than January, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Cupertino is mildly breezy, with an average annual wind speed of 15km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 17km/h, though still comfortable for most outdoor activities. The calmest conditions occur in November, with average winds dropping to 13km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 4km/h between the calmest and windiest months.

It is currently spring in Cupertino, which began on March 20, 2026. Cupertino is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in September at around 23°C, while the coldest stretch bottoms out in February near 9°C. Summer is next, beginning on June 21, 2026 — 88 days from now.

The best time to visit Cupertino is during June, July, August, September and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 6mm per month. By contrast, February can be quite cold with temperatures dropping to 9°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Cupertino based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.