Duncan, OK 73536 Frost Dates
73536, near Duncan, OK: the frost window
The last spring frost here typically falls around 03/28, about 212 days from today. Fall's first freeze usually shows up around 11/07, roughly 227 days after the last spring frost.
Zone 8a (10 to 15°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 Duncan, not a forecast for this year.
Stretching the season past the first frost
Duncan'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.
How much risk comes with planting early here
03/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/18 and only about 1 year in 10 sees frost after that.
Duncan against the rest of the dataset
At roughly 227 frost-free days, Duncan places 10,965 of 40,283 ZIP codes in this dataset. Within OK, it ranks 69 of 764.
Learn more
Two guides worth reading on 73536: local microclimates, on what one yard in Duncan can differ from the 73536 normal, and zone vs. frost date, on why Zone 8a and Duncan's frost date answer different questions.