Duncan, OK 73533 Frost Dates
Frost dates for Duncan, OK, ZIP 73533
The last spring frost here typically falls around 03/28, about 212 days from today. The first fall frost typically arrives around 11/07, about 227 frost-free days later.
The USDA Plant Hardiness Zone Map puts Duncan in Zone 8a (10 to 15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 8a around Duncan has about 10 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
03/28 is the middle of 30 years of NOAA records, not a promise. Plant by 03/06 and you're betting against frost in roughly 9 years out of 10. 04/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Duncan compares
Duncan's growing season runs about 227 days, ranking 10,963 of 40,283 US ZIP codes measured here, longest to shortest. Within OK, it ranks 67 of 764.
Learn more
the frost range explains how to read the range around Duncan's dates instead of trusting one, and local microclimates explains what one yard in Duncan can differ from the 73533 normal.