Harman US

Hercules, CA Weather & Growing Conditions

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

This Afternoon
70°F
Sunny
Sunny, with a high near 70. Southwest wind 8 to 12 mph.

7-day forecast for Hercules

WhenTempForecastWindPrecip
This Afternoon 70°F Sunny 8 to 12 mph SW 0%
Tonight 58°F Mostly Clear 7 to 10 mph SW 0%
Saturday 71°F Sunny 7 to 10 mph SSW 0%
Saturday Night 59°F Partly Cloudy 9 mph SSW 0%
Sunday 64°F Partly Sunny 10 mph SW 1%
Sunday Night 58°F Mostly Cloudy 10 mph SW 1%
Monday 66°F Mostly Sunny 9 to 13 mph SW 0%
Monday Night 58°F Partly Cloudy 8 to 13 mph SW 0%
Tuesday 72°F Sunny 7 to 12 mph SW 0%
Tuesday Night 58°F Mostly Clear 3 to 12 mph SSW 0%
Wednesday 82°F Sunny 2 to 7 mph SW 0%
Wednesday Night 60°F Mostly Clear 3 to 7 mph SW 0%
Thursday 82°F Sunny 2 to 9 mph SW 0%
Thursday Night 61°F Partly Cloudy 6 to 9 mph SW 0%

Forecast source: National Weather Service (api.weather.gov) for Hercules (38.021, -122.289). Updated through the day.

Growing snapshot for Hercules

Last spring frost
Jan 4
First fall frost
Jan 2
Growing season
365 days
Hardiness zone
9b

More local growing data for Hercules: nearby ZIP 94564 weather · frost dates · planting calendar · California frost dates

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Climate data from the nearest NOAA station, Richmond, Ca (7.5 mi from Hercules). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.