Hercules, CA Weather & Growing Conditions
Tonight
56°F
Mostly Cloudy
Mostly cloudy, with a low around 56. South southwest wind around 9 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 56°F | Mostly Cloudy | 9 mph SSW | 0% |
| Sunday | 69°F | Mostly Cloudy | 7 to 10 mph SSW | 0% |
| Sunday Night | 56°F | Mostly Cloudy | 9 mph SSW | 0% |
| Monday | 68°F | Mostly Sunny | 9 to 13 mph SW | 1% |
| Monday Night | 56°F | Partly Cloudy | 8 to 13 mph SW | 1% |
| Tuesday | 71°F | Mostly Sunny | 7 to 10 mph SW | 0% |
| Tuesday Night | 56°F | Mostly Clear | 3 to 10 mph SW | 0% |
| Wednesday | 83°F | Sunny | 2 to 7 mph WSW | 0% |
| Wednesday Night | 58°F | Mostly Clear | 2 to 7 mph SW | 0% |
| Thursday | 86°F | Sunny | 2 to 8 mph WSW | 0% |
| Thursday Night | 59°F | Mostly Clear | 5 to 8 mph SW | 0% |
| Friday | 78°F | Mostly Sunny | 6 to 10 mph SW | 0% |
| Friday Night | 58°F | Partly Cloudy | 7 to 10 mph SW | 1% |
| Saturday | 72°F | Sunny | 7 to 10 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Hercules, CA
Last spring frost
Jan 17
First fall frost
Dec 27
Growing season
346 days
Hardiness zone
9b
Explore more for Hercules, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Vallejo, Ca (7.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.