San Bernardino, CA 92405 Frost Dates
92405, near San Bernardino, CA: the frost window
The last spring frost here typically falls around 01/27, about 152 days from today. Fall's first freeze usually shows up around 12/19, roughly 329 days after the last spring frost.
San Bernardino sits in USDA Zone 10a (30 to 35°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
San Bernardino's growing season runs out in roughly 16 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 San Bernardino's last frost
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
At roughly 329 frost-free days, San Bernardino places 3,066 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,319 of 2,555.
Learn more
Two guides worth reading on 92405: local microclimates, on what one yard in San Bernardino can differ from the 92405 normal, and zone vs. frost date, on why Zone 10a and San Bernardino's frost date answer different questions.