Norman, OK 73071 Frost Dates
73071, near Norman, OK: the frost window
Around 03/31 is the usual last spring frost, about 215 days away. Fall's first freeze usually shows up around 11/05, roughly 219 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Norman in Zone 7b (5 to 10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Norman'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 Norman's last frost
03/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/17 and only about 1 year in 10 sees frost after that.
Norman against the rest of the dataset
At roughly 219 frost-free days, Norman places 12,923 of 40,283 ZIP codes in this dataset. Within OK, it ranks 216 of 764.
Learn more
Two guides worth reading on 73071: local microclimates, on what one yard in Norman can differ from the 73071 normal, and zone vs. frost date, on why Zone 7b and Norman's frost date answer different questions.