Harman US

Blackhawk, CA Weather & Growing Conditions

Overnight
55°F
Patchy Fog
Patchy fog after 3am. Partly cloudy, with a low around 55. Southwest wind around 2 mph.

7-day forecast

WhenTempForecastWindPrecip
Overnight 55°F Patchy Fog 2 mph SW 0%
Saturday 85°F Patchy Fog then Sunny 2 to 7 mph SW 0%
Saturday Night 54°F Partly Cloudy 2 to 6 mph SW 0%
Sunday 76°F Mostly Cloudy 2 to 7 mph WSW 3%
Sunday Night 54°F Mostly Cloudy 2 to 7 mph WSW 3%
Monday 78°F Mostly Sunny 3 to 8 mph WSW 0%
Monday Night 54°F Partly Cloudy 1 to 8 mph WSW 0%
Tuesday 82°F Patchy Fog then Sunny 1 to 7 mph WSW 0%
Tuesday Night 54°F Mostly Clear 0 to 7 mph SW 0%
Wednesday 92°F Sunny 0 to 6 mph WNW 0%
Wednesday Night 60°F Mostly Clear 0 to 6 mph W 0%
Thursday 93°F Sunny 0 to 7 mph WSW 0%
Thursday Night 58°F Mostly Clear 1 to 7 mph WSW 0%
Friday 85°F Mostly Sunny 1 to 8 mph WSW 0%

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

Growing snapshot for Blackhawk, CA

Last spring frost
Mar 8
First fall frost
Dec 22
Growing season
282 days
Hardiness zone
9b

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

Climate data from the nearest NOAA station, Mt Diablo Junction, Ca (5.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.