Mertzon, TX 76909 Frost Dates
Frost dates for Mertzon, TX, ZIP 76909
Typically, the last spring freeze lands around 04/01, roughly 216 days out. The first fall frost typically arrives around 11/04, about 215 frost-free days later.
Mertzon sits in USDA Zone 8a (10 to 15°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 8a around Mertzon has about 10 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 Mertzon's last frost
04/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/14 and you're betting against frost in roughly 9 years out of 10. 04/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mertzon compares
Mertzon's growing season runs about 215 days, ranking 14,157 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 2,348 of 2,558.
Learn more
zone vs. frost date explains why Zone 8a and Mertzon's frost date answer different questions, and the frost range explains how to read the range around Mertzon's dates instead of trusting one.