Blackhawk, CA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Blackhawk, a community in Contra Costa County, California.

This Afternoon

81°F

Sunny

Sunny, with a high near 81. West wind around 8 mph.

7-day forecast for Blackhawk

When	Temp	Forecast	Wind	Precip
This Afternoon	81°F	Sunny	8 mph W	0%
Tonight	55°F	Mostly Clear then Patchy Fog	2 to 7 mph SW	0%
Saturday	86°F	Patchy Fog then Sunny	1 to 7 mph WSW	0%
Saturday Night	55°F	Mostly Cloudy	2 to 6 mph SW	0%
Sunday	76°F	Partly Sunny	2 to 7 mph SW	3%
Sunday Night	54°F	Mostly Cloudy	2 to 7 mph SW	3%
Monday	79°F	Mostly Sunny	2 to 8 mph WSW	0%
Monday Night	54°F	Mostly Clear	2 to 8 mph WSW	0%
Tuesday	83°F	Patchy Fog then Sunny	2 to 7 mph WSW	0%
Tuesday Night	56°F	Mostly Clear	0 to 7 mph SW	0%
Wednesday	94°F	Sunny	0 to 5 mph WNW	0%
Wednesday Night	61°F	Mostly Clear	0 to 5 mph W	0%
Thursday	94°F	Sunny	0 to 7 mph WSW	0%
Thursday Night	60°F	Mostly Clear	0 to 7 mph WSW	0%

Forecast source: National Weather Service (api.weather.gov) for Blackhawk (37.810, -121.913). Updated through the day.

Growing snapshot for Blackhawk

Last spring frost

Mar 8

First fall frost

Dec 22

Growing season

282 days

Hardiness zone

More local growing data for Blackhawk: nearby ZIP 94506 weather · frost dates · planting calendar · California frost dates

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