Alvin, TX 77511 Frost Dates
77511, near Alvin, TX: the frost window
The last spring frost here typically falls around 01/31, about 156 days from today. Fall's first freeze usually shows up around 12/27, roughly 328 days after the last spring frost.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Alvin, not a forecast for this year.
Stretching the season past the first frost
Alvin's growing season runs out in roughly 17 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/31 isn't a guarantee
01/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/05 and only about 1 year in 10 sees frost after that.
Alvin against the rest of the dataset
About 328 days separate Alvin's last and first frost, putting it 3,180 of 40,283 ZIP codes nationally. Within TX, it ranks 188 of 2,558.
Learn more
Two guides worth reading on 77511: zone vs. frost date, on why Zone 9b and Alvin's frost date answer different questions, and the frost range, on how to read the range around Alvin's dates instead of trusting one.