San Marino, CA 91107 Frost Dates
91107, near San Marino, CA: the frost window
The last spring frost here typically falls around 01/08, about 133 days from today. Fall's first freeze usually shows up around 01/07, roughly 365 days after the last spring frost.
San Marino 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 Marino's growing season runs out in roughly 19 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 Marino's last frost
01/08 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 12/20 and only about 1 year in 10 sees frost after that.
San Marino against the rest of the dataset
At roughly 365 frost-free days, San Marino places 1,697 of 40,283 ZIP codes in this dataset. Within CA, it ranks 827 of 2,555.
Learn more
Two guides worth reading on 91107: zone vs. frost date, on why Zone 10a and San Marino's frost date answer different questions, and the frost range, on how to read the range around San Marino's dates instead of trusting one.