FrostDateCheck

Rio Bravo, TX 78046 Frost Dates

Frost dates for Rio Bravo, TX, ZIP 78046

Zone 9b

Typically, the last spring freeze lands around 01/20, roughly 145 days out. The first fall frost typically arrives around 12/25, about 344 frost-free days later.

Rio Bravo sits in USDA Zone 9b (25 to 30°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 9b around Rio Bravo has about 17 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 01/20 isn't a guarantee

01/20 is the middle of 30 years of NOAA records, not a promise. Plant by 02/26 and you're betting against frost in roughly 9 years out of 10. 12/16 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Rio Bravo compares

At roughly 344 frost-free days, Rio Bravo places 2,459 of 40,283 ZIP codes in this dataset. Within TX, it ranks 93 of 2,558.

Learn more

local microclimates explains what one yard in Rio Bravo can differ from the 78046 normal, and zone vs. frost date explains why Zone 9b and Rio Bravo's frost date answer different questions.