Portland, TX 78466 Frost Dates
78466, near Portland, TX: the frost window
Typically, the last spring freeze lands around 01/28, roughly 153 days out. Fall's first freeze usually shows up around 12/21, roughly 331 days after the last spring frost.
Portland sits in USDA Zone 10a (30 to 35°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.
Stretching the season past the first frost
Portland's growing season runs out in roughly 16 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/28 isn't a guarantee
01/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/16 and only about 1 year in 10 sees frost after that.
Portland against the rest of the dataset
Portland's growing season runs about 331 days, ranking 2,940 of 40,283 US ZIP codes measured here, longest to shortest. Within TX, it ranks 126 of 2,558.
Learn more
Two guides worth reading on 78466: the frost range, on how to read the range around Portland's dates instead of trusting one, and local microclimates, on what one yard in Portland can differ from the 78466 normal.