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

65°F

Sunny

Sunny. High near 65, with temperatures falling to around 61 in the afternoon. Northwest wind around 7 mph.

7-day forecast for Blackhawk

When	Temp	Forecast	Wind	Precip
This Afternoon	65°F	Sunny	7 mph NW	1%
Tonight	45°F	Mostly Cloudy then Patchy Fog	2 mph NW	1%
Thursday	69°F	Patchy Fog then Sunny	1 to 6 mph NW	0%
Thursday Night	47°F	Mostly Clear	2 mph WSW	0%
Friday	70°F	Sunny	0 to 5 mph N	0%
Friday Night	48°F	Mostly Clear	1 mph N	0%
Saturday	72°F	Sunny	0 to 3 mph NE	0%
Saturday Night	48°F	Mostly Clear	1 mph NNE	0%
Sunday	72°F	Sunny	0 to 3 mph NNW	0%
Sunday Night	50°F	Partly Cloudy	2 mph NNW	0%
Monday	70°F	Mostly Sunny	0 to 3 mph W	0%
Monday Night	49°F	Partly Cloudy	0 to 3 mph W	1%
Tuesday	71°F	Mostly Sunny	0 to 3 mph NW	1%
Tuesday Night	50°F	Partly Cloudy	0 to 3 mph WSW	7%

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 Nov 4, 2026.