FrostDateCheck

Castle Hills, TX 78213 Frost Dates

Frost dates for Castle Hills, TX, ZIP 78213

Zone 9a

Around 02/26 is the usual last spring frost, about 182 days away. The first fall frost typically arrives around 11/28, about 277 frost-free days later.

Castle Hills 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 Castle Hills 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.

The actual range around Castle Hills's last frost

02/26 is the middle of 30 years of NOAA records, not a promise. Plant by 01/29 and you're betting against frost in roughly 9 years out of 10. 03/17 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Castle Hills compares

Castle Hills's growing season runs about 277 days, ranking 5,013 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 811 of 2,558.

Learn more

the frost range explains how to read the range around Castle Hills's dates instead of trusting one, and local microclimates explains what one yard in Castle Hills can differ from the 78213 normal.