Alamo Heights, TX 78209 Frost Dates
78209, near Alamo Heights, TX: the frost window
The last spring frost here typically falls around 02/25, about 181 days from today. Fall's first freeze usually shows up around 11/28, roughly 277 days after the last spring frost.
Zone 9a (20 to 25°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 Alamo Heights, not a forecast for this year.
Stretching the season past the first frost
Alamo Heights's growing season runs out in roughly 13 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
02/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/19 and only about 1 year in 10 sees frost after that.
Alamo Heights against the rest of the dataset
About 277 days separate Alamo Heights's last and first frost, putting it 4,976 of 40,283 ZIP codes nationally. Within TX, it ranks 779 of 2,558.
Learn more
Two guides worth reading on 78209: zone vs. frost date, on why Zone 9a and Alamo Heights's frost date answer different questions, and the frost range, on how to read the range around Alamo Heights's dates instead of trusting one.