San Antonio, TX 78204 Frost Dates
Frost dates for San Antonio, TX, ZIP 78204
Typically, the last spring freeze lands around 02/22, roughly 178 days out. 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.
The actual range around San Antonio's last frost
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
About 284 days separate San Antonio's last and first frost, putting it 4,655 of 40,283 ZIP codes nationally. Within TX, it ranks 717 of 2,558.
Learn more
local microclimates explains what one yard in San Antonio can differ from the 78204 normal, and zone vs. frost date explains why Zone 9a and San Antonio's frost date answer different questions.