Frost Dates for Brentwood, CA

Based on data from Antioch Pumping Plt #3 weather station, 5 miles away

Elevation: 79 ft

Frost Dates

Last Spring Frost (50%) A 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. January 12
First Fall Frost (50%) A 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. December 19

30% Probability

Only a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.
Last Spring Frost January 22
First Fall Frost December 10

Hard Freeze (28°F)

Last Spring Hard Freeze January 2
First Fall Hard Freeze December 29
37.93°N, 121.70°W © OpenStreetMap

Growing Season

342 Days January 12 to December 19

USDA Hardiness Zone

Hardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.
Zone 9b

Avg. annual minimum: 25 to 30°F

Learn more

Köppen Climate

The Köppen climate classification system categorizes climates based on temperature and precipitation patterns.
Csa Hot-Summer Mediterranean

Hot, dry summers and mild, wet winters. Classic Mediterranean climate ideal for grapes, olives, tomatoes, and herbs. Summer irrigation is usually necessary.

Köppen climate map

Temperature

Avg High Avg Temp Avg Low
Temperature table
Average monthly temperatures (°F)
Month Avg High Avg Temp Avg Low
January56°48°40°
February61°52°44°
March67°57°47°
April72°61°50°
May79°67°54°
June86°73°59°
July91°76°61°
August90°75°60°
September87°73°59°
October78°66°54°
November65°55°46°
December56°48°40°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January4.3
February4.4
March4.5
April3.0
May0.0
June0.0
July0.0
August0.0
September0.0
October0.0
November3.4
December4.5

Sunrise / Sunset

Daylight Pacific Time (PT) Longest: 14h 38m · Shortest: 9h 22m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (Pacific Time (PT))
Month Sunrise Sunset Daylight
January7:27 AM5:06 PM9h 38m
February7:04 AM5:39 PM10h 35m
March7:25 AM7:08 PM11h 42m
April6:37 AM7:37 PM12h 60m
May6:02 AM8:05 PM14h 03m
June5:49 AM8:26 PM14h 37m
July6:01 AM8:24 PM14h 23m
August6:27 AM7:55 PM13h 28m
September6:55 AM7:08 PM12h 14m
October7:23 AM6:22 PM10h 59m
November6:55 AM4:49 PM9h 54m
December7:22 AM4:44 PM9h 23m

Nearby Stations

Mt Diablo Junction, CA March 8 - December 22 Tracy Pumping Plt, CA January 19 - December 10 Concord Buchanan Fld, CA January 9 - December 14 Concord Wwtp, CA January 7 - December 19 Martinez Wtp, CA February 28 - November 22 Livermore Muni AP, CA February 27 - December 1

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