San Marino, CA 91108 Frost Dates
When can you plant in San Marino, CA?
Around 01/08 is the usual last spring frost, about 133 days away. The first fall frost typically arrives around 01/07, about 365 frost-free days later.
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.
What to do before the first frost
About 19 weeks of growing season left in San Marino before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
01/08 is the middle of 30 years of NOAA records, not a promise. Plant by 02/17 and you're betting against frost in roughly 9 years out of 10. 12/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Marino compares
About 365 days separate San Marino's last and first frost, putting it 1,698 of 40,283 ZIP codes nationally. Within CA, it ranks 828 of 2,555.
Learn more
the frost range covers how to read the range around San Marino's dates instead of trusting one. local microclimates covers what one yard in San Marino can differ from the 91108 normal.