Brentwood, CA 94514 Frost Dates
94514, near Brentwood, CA: the frost window
Typically, the last spring freeze lands around 01/19, roughly 144 days out. Fall's first freeze usually shows up around 12/10, roughly 330 days after the last spring frost.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Brentwood, not a forecast for this year.
Stretching the season past the first frost
Brentwood's growing season runs out in roughly 15 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Brentwood's last frost
01/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/25 and only about 1 year in 10 sees frost after that.
Brentwood against the rest of the dataset
About 330 days separate Brentwood's last and first frost, putting it 3,000 of 40,283 ZIP codes nationally. Within CA, it ranks 1,313 of 2,555.
Learn more
Two guides worth reading on 94514: local microclimates, on what one yard in Brentwood can differ from the 94514 normal, and zone vs. frost date, on why Zone 9b and Brentwood's frost date answer different questions.