Bethel Island, CA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Bethel Island, a community in Contra Costa County, California.

Overnight

50°F

Mostly Clear

Mostly clear, with a low around 50. Northwest wind around 9 mph, with gusts as high as 18 mph.

7-day forecast for Bethel Island

When	Temp	Forecast	Wind	Precip
Overnight	50°F	Mostly Clear	9 mph NW	0%
Wednesday	69°F	Sunny	7 to 13 mph NW	1%
Wednesday Night	50°F	Mostly Cloudy	7 mph W	1%
Thursday	72°F	Mostly Sunny	5 to 9 mph NW	0%
Thursday Night	48°F	Mostly Clear	1 to 5 mph W	0%
Friday	71°F	Sunny	0 to 5 mph NNW	0%
Friday Night	49°F	Mostly Clear	0 mph	0%
Saturday	72°F	Sunny	0 to 3 mph NNE	0%
Saturday Night	50°F	Mostly Clear	2 mph WNW	0%
Sunday	72°F	Sunny	0 to 5 mph NW	0%
Sunday Night	51°F	Partly Cloudy	0 mph	0%
Monday	71°F	Mostly Sunny	0 to 5 mph WNW	0%
Monday Night	51°F	Partly Cloudy	3 mph W	1%
Tuesday	72°F	Patchy Fog then Sunny	0 to 3 mph NW	5%

Forecast source: National Weather Service (api.weather.gov) for Bethel Island (38.028, -121.630). Updated through the day.

Growing snapshot for Bethel Island

Last spring frost

Jan 12

First fall frost

Dec 19

Growing season

343 days

Hardiness zone

More local growing data for Bethel Island: nearby ZIP 94511 weather · frost dates · planting calendar · California frost dates

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Climate data from the nearest NOAA station, Antioch Pumping Plt #3, Ca (7.4 mi from Bethel Island). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.