Duncan, OK 73534 Frost Dates
Duncan, OK: when does the frost end?
Around 03/28 is the usual last spring frost, about 212 days away. Fall's first freeze usually shows up around 11/07, roughly 227 days after the last spring frost.
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.
Stretching the season past the first frost
With roughly 10 weeks until Duncan's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Duncan's last frost
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
About 227 days separate Duncan's last and first frost, putting it 10,964 of 40,283 ZIP codes nationally. Within OK, it ranks 68 of 764.
Learn more
Before leaning on 73534's figures: zone vs. frost date explains why Zone 8a and Duncan's frost date answer different questions, while the frost range explains how to read the range around Duncan's dates instead of trusting one.