San Antonio, FL 34639 Frost Dates
When can you plant in San Antonio, FL?
Typically, the last spring freeze lands around 01/31, roughly 156 days out. The first fall frost typically arrives around 01/08, about 336 frost-free days later.
San Antonio sits in USDA Zone 9b (25 to 30°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 Antonio before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 01/31 isn't a guarantee
01/31 is the middle of 30 years of NOAA records, not a promise. Plant by 01/03 and you're betting against frost in roughly 9 years out of 10. 02/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Antonio compares
At roughly 336 frost-free days, San Antonio places 2,734 of 40,283 ZIP codes in this dataset. Within FL, it ranks 1,101 of 1,609.
Learn more
local microclimates covers what one yard in San Antonio can differ from the 34639 normal. zone vs. frost date covers why Zone 9b and San Antonio's frost date answer different questions.