Portland, TX 78401 Frost Dates
Frost dates for Portland, TX, ZIP 78401
Typically, the last spring freeze lands around 01/28, roughly 153 days out. The first fall frost typically arrives around 12/21, about 331 frost-free days later.
The USDA Plant Hardiness Zone Map puts Portland 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 Portland has about 16 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 01/28 isn't a guarantee
01/28 is the middle of 30 years of NOAA records, not a promise. Plant by 02/28 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 Portland compares
Portland's growing season runs about 331 days, ranking 2,930 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 116 of 2,558.
Learn more
local microclimates explains what one yard in Portland can differ from the 78401 normal, and zone vs. frost date explains why Zone 10a and Portland's frost date answer different questions.