San Bernardino, CA 92410 Frost Dates
San Bernardino, CA: when does the frost end?
Typically, the last spring freeze lands around 01/27, roughly 152 days out. Fall's first freeze usually shows up around 12/19, roughly 329 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts San Bernardino in Zone 10a (30 to 35°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 16 weeks until San Bernardino's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 01/27 isn't a guarantee
01/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/21 and only about 1 year in 10 sees frost after that.
San Bernardino against the rest of the dataset
About 329 days separate San Bernardino's last and first frost, putting it 3,067 of 40,283 ZIP codes nationally. Within CA, it ranks 1,320 of 2,555.
Learn more
Before leaning on 92410's figures: local microclimates explains what one yard in San Bernardino can differ from the 92410 normal, while zone vs. frost date explains why Zone 10a and San Bernardino's frost date answer different questions.