Brentwood, CA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Brentwood, a city in Contra Costa County, California.
Tonight
51°F
Partly Cloudy
Partly cloudy, with a low around 51. Northwest wind around 3 mph.
7-day forecast for Brentwood
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Partly Cloudy | 3 mph NW | 0% |
| Wednesday | 69°F | Sunny | 2 to 8 mph NW | 1% |
| Wednesday Night | 51°F | Mostly Cloudy | 5 mph W | 2% |
| Thursday | 72°F | Mostly Sunny | 2 to 6 mph NW | 0% |
| Thursday Night | 50°F | Clear | 0 to 3 mph W | 0% |
| Friday | 72°F | Sunny | 0 to 3 mph NW | 0% |
| Friday Night | 51°F | Mostly Clear | 2 mph NNW | 0% |
| Saturday | 73°F | Sunny | 2 mph NNE | 0% |
| Saturday Night | 52°F | Mostly Clear | 2 mph NNW | 0% |
| Sunday | 73°F | Sunny | 3 mph NW | 0% |
| Sunday Night | 53°F | Partly Cloudy | 2 mph NNW | 0% |
| Monday | 72°F | Mostly Sunny | 0 to 3 mph WNW | 0% |
| Monday Night | 52°F | Partly Cloudy | 0 to 3 mph W | 1% |
| Tuesday | 71°F | Sunny | 2 mph WNW | 5% |
Forecast source: National Weather Service (api.weather.gov) for Brentwood (37.936, -121.719). Updated through the day.
Growing snapshot for Brentwood
Last spring frost
Jan 12
First fall frost
Dec 19
Growing season
343 days
Hardiness zone
9b
More local growing data for Brentwood: nearby ZIP 94513 weather · frost dates · planting calendar · California frost dates
Nearby towns & communities
Acalanes Ridge
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Alhambra Valley
Antioch
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Benicia
Bethel Island
Blackhawk
Byron
Castle Hill
Clayton
Clyde
Concord
Contra Costa Centre
Crockett
Danville
Diablo
Discovery Bay
East Richmond Heights
El Cerrito
El Sobrante
Hercules
Knightsen
Lafayette
Martinez
Montalvin Manor
Moraga
Mountain View
Norris Canyon
Climate data from the nearest NOAA station, Antioch Pumping Plt #3, Ca (5.4 mi from Brentwood). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.