Petronila, TX 78417 Frost Dates
78417, near Petronila, 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.
Zone 10a (30 to 35°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 Petronila, not a forecast for this year.
Stretching the season past the first frost
Petronila'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.
The actual range around Petronila's last frost
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.
Petronila against the rest of the dataset
About 353 days separate Petronila's last and first frost, putting it 2,249 of 40,283 ZIP codes nationally. Within TX, it ranks 76 of 2,558.
Learn more
Two guides worth reading on 78417: zone vs. frost date, on why Zone 10a and Petronila's frost date answer different questions, and the frost range, on how to read the range around Petronila's dates instead of trusting one.