Altus, OK 73521 Frost Dates
73521, near Altus, OK: the frost window
Typically, the last spring freeze lands around 04/03, roughly 218 days out. Fall's first freeze usually shows up around 11/04, roughly 214 days after the last spring frost.
Altus sits in USDA Zone 7b (5 to 10°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
Altus's growing season runs out in roughly 10 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 Altus's last frost
04/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/21 and only about 1 year in 10 sees frost after that.
Altus against the rest of the dataset
At roughly 214 frost-free days, Altus places 14,230 of 40,283 ZIP codes in this dataset. Within OK, it ranks 368 of 764.
Learn more
Two guides worth reading on 73521: the frost range, on how to read the range around Altus's dates instead of trusting one, and local microclimates, on what one yard in Altus can differ from the 73521 normal.