San Antonio, TX 78226 Frost Dates
Frost dates for San Antonio, TX, ZIP 78226
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.
San Antonio sits in USDA Zone 9a (20 to 25°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
Zone 9a around San Antonio has about 14 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
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 4,658 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 720 of 2,558.
Learn more
local microclimates explains what one yard in San Antonio can differ from the 78226 normal, and zone vs. frost date explains why Zone 9a and San Antonio's frost date answer different questions.