Harman US

Hillsborough, CA Weather & Growing Conditions

Today
75°F
Sunny
Sunny. High near 75, with temperatures falling to around 70 in the afternoon. West wind 3 to 14 mph, with gusts as high as 20 mph.

7-day forecast

WhenTempForecastWindPrecip
Today 75°F Sunny 3 to 14 mph W 0%
Tonight 56°F Partly Cloudy 6 to 13 mph WSW 1%
Sunday 69°F Mostly Cloudy 6 to 10 mph W 3%
Sunday Night 57°F Mostly Cloudy 3 to 10 mph W 3%
Monday 72°F Mostly Sunny 3 to 12 mph WSW 2%
Monday Night 56°F Partly Cloudy 3 to 12 mph WSW 2%
Tuesday 74°F Mostly Sunny 3 to 10 mph WSW 1%
Tuesday Night 56°F Mostly Clear 2 to 10 mph WSW 0%
Wednesday 82°F Sunny 1 to 9 mph SW 0%
Wednesday Night 58°F Mostly Clear 0 to 9 mph WSW 0%
Thursday 84°F Sunny 0 to 10 mph WSW 0%
Thursday Night 58°F Mostly Clear 5 to 10 mph WSW 0%
Friday 78°F Mostly Sunny 5 to 13 mph WSW 0%
Friday Night 57°F Partly Cloudy 5 to 13 mph WSW 2%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Hillsborough, CA

Last spring frost
Dec 29
First fall frost
Dec 26
Growing season
365 days
Hardiness zone
10a

Explore more for Hillsborough, CA: full frost dates · planting calendar · California frost dates

Climate data from the nearest NOAA station, San Francisco Intl Ap, Ca (3.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.