San Antonio, TX 78237 Frost Dates
When can you plant in San Antonio, TX?
The last spring frost here typically falls around 02/22, about 178 days from today. The first fall frost typically arrives around 12/02, about 284 frost-free days later.
Zone 9a (20 to 25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for San Antonio, not a forecast for this year.
What to do before the first frost
About 14 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 02/22 isn't a guarantee
02/22 is the middle of 30 years of NOAA records, not a promise. Plant by 01/16 and you're betting against frost in roughly 9 years out of 10. 03/12 is the safer bet, historically only a 1-in-10 chance of frost that late.
How San Antonio compares
San Antonio's growing season runs about 284 days, ranking 4,659 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 721 of 2,558.
Learn more
zone vs. frost date covers why Zone 9a and San Antonio's frost date answer different questions. the frost range covers how to read the range around San Antonio's dates instead of trusting one.