Harman US

Blackhawk, CA Weather & Growing Conditions

Overnight
60°F
Mostly Clear
Mostly clear, with a low around 60. West wind around 2 mph.

7-day forecast

WhenTempForecastWindPrecip
Overnight 60°F Mostly Clear 2 mph W 0%
Tuesday 99°F Sunny 2 to 8 mph WSW 0%
Tuesday Night 59°F Mostly Clear 2 to 7 mph W 0%
Wednesday 95°F Sunny 2 to 7 mph WSW 0%
Wednesday Night 58°F Mostly Clear 2 to 7 mph WSW 0%
Thursday 92°F Sunny 2 to 8 mph WSW 0%
Thursday Night 60°F Mostly Clear 2 to 8 mph WSW 0%
Friday 96°F Sunny 2 to 8 mph WSW 0%
Friday Night 62°F Mostly Clear 2 to 8 mph WSW 0%
Saturday 96°F Sunny 2 to 9 mph WSW 0%
Saturday Night 62°F Mostly Clear 3 to 9 mph SW 0%
Sunday 89°F Sunny 3 to 9 mph SW 0%
Sunday Night 58°F Mostly Clear 9 mph SW 0%
Monday 84°F Sunny 7 to 10 mph SW 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 Aug 4, 2026.