Seguin, TX 78123 Frost Dates
Frost dates for Seguin, TX, ZIP 78123
Around 03/01 is the usual last spring frost, about 185 days away. The first fall frost typically arrives around 11/26, about 273 frost-free days later.
Seguin 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 Seguin has about 13 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 03/01 isn't a guarantee
03/01 is the middle of 30 years of NOAA records, not a promise. Plant by 02/03 and you're betting against frost in roughly 9 years out of 10. 03/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Seguin compares
About 273 days separate Seguin's last and first frost, putting it 5,184 of 40,283 ZIP codes nationally. Within TX, it ranks 862 of 2,558.
Learn more
local microclimates explains what one yard in Seguin can differ from the 78123 normal, and zone vs. frost date explains why Zone 9a and Seguin's frost date answer different questions.