Brownsville, TX 78521 Frost Dates
Frost dates for Brownsville, TX, ZIP 78521
Typically, the last spring freeze lands around 01/06, roughly 131 days out. The first fall frost typically arrives around 01/02, about 365 frost-free days later.
The USDA Plant Hardiness Zone Map puts Brownsville in Zone 10a (30 to 35°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 10a around Brownsville has about 18 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.
How much risk comes with planting early here
01/06 is the middle of 30 years of NOAA records, not a promise. Plant by 02/01 and you're betting against frost in roughly 9 years out of 10. 12/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Brownsville compares
Brownsville's growing season runs about 365 days, ranking 359 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 4 of 2,558.
Learn more
the frost range explains how to read the range around Brownsville's dates instead of trusting one, and local microclimates explains what one yard in Brownsville can differ from the 78521 normal.