Portland, TX 78405 Frost Dates
Frost dates for Portland, TX, ZIP 78405
Around 01/28 is the usual last spring frost, about 153 days away. 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.
How much risk comes with planting early here
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 2,933 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 119 of 2,558.
Learn more
local microclimates explains what one yard in Portland can differ from the 78405 normal, and zone vs. frost date explains why Zone 10a and Portland's frost date answer different questions.