Portland, TX 78404 Frost Dates
78404, near Portland, TX: the frost window
Around 01/15 is the usual last spring frost, about 140 days away. Fall's first freeze usually shows up around 12/30, roughly 353 days after the last spring frost.
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.
Stretching the season past the first frost
Portland's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/15 isn't a guarantee
01/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/11 and only about 1 year in 10 sees frost after that.
Portland against the rest of the dataset
At roughly 353 frost-free days, Portland places 2,229 of 40,283 ZIP codes in this dataset. Within TX, it ranks 69 of 2,558.
Learn more
Two guides worth reading on 78404: local microclimates, on what one yard in Portland can differ from the 78404 normal, and zone vs. frost date, on why Zone 10a and Portland's frost date answer different questions.