Blackhawk, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Blackhawk, a community in Contra Costa County, California.
Tonight
46°F
Patchy Fog
Patchy fog. Partly cloudy, with a low around 46. Northeast wind around 2 mph.
7-day forecast for Blackhawk
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 46°F | Patchy Fog | 2 mph NE | 6% |
| Wednesday | 65°F | Patchy Fog then Sunny | 1 to 7 mph NNW | 1% |
| Wednesday Night | 46°F | Mostly Cloudy then Patchy Fog | 2 mph WNW | 2% |
| Thursday | 69°F | Patchy Fog then Mostly Sunny | 0 to 5 mph N | 0% |
| Thursday Night | 46°F | Mostly Clear | 2 mph NNW | 0% |
| Friday | 71°F | Sunny | 0 to 5 mph N | 0% |
| Friday Night | 48°F | Mostly Clear | 0 mph | 0% |
| Saturday | 72°F | Sunny | 0 to 3 mph NNE | 0% |
| Saturday Night | 48°F | Mostly Clear | 0 mph | 0% |
| Sunday | 72°F | Sunny | 0 to 3 mph N | 0% |
| Sunday Night | 50°F | Partly Cloudy | 0 mph | 0% |
| Monday | 70°F | Mostly Sunny | 0 to 3 mph W | 1% |
| Monday Night | 49°F | Partly Cloudy | 0 to 3 mph NW | 1% |
| Tuesday | 70°F | Sunny | 0 to 3 mph NNW | 5% |
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
9b
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.