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Duncan, OK Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Duncan, a city in Stephens County, Oklahoma.

Today
104°F
Sunny
Sunny, with a high near 104. Heat index values as high as 103. South wind around 10 mph.

7-day forecast for Duncan

WhenTempForecastWindPrecip
Today 104°F Sunny 10 mph S 1%
Tonight 76°F Mostly Clear 7 to 12 mph SSE 2%
Wednesday 103°F Sunny 7 to 13 mph SSW 2%
Wednesday Night 76°F Mostly Clear 8 to 13 mph SSE 1%
Thursday 102°F Mostly Sunny 7 to 12 mph SSW 9%
Thursday Night 75°F Mostly Clear 8 to 12 mph SSE 11%
Friday 100°F Mostly Sunny then Slight Chance Showers And Thunderstorms 7 to 12 mph S 24%
Friday Night 73°F Slight Chance Showers And Thunderstorms then Mostly Clear 8 to 13 mph SSE 24%
Saturday 100°F Sunny 7 to 13 mph S 8%
Saturday Night 74°F Mostly Clear 9 to 14 mph S 6%
Sunday 100°F Sunny 8 to 15 mph S 2%
Sunday Night 74°F Mostly Clear 12 to 15 mph SSE 1%
Monday 100°F Sunny 10 to 16 mph S 2%
Monday Night 75°F Mostly Clear 12 to 16 mph SSE 2%

Forecast source: National Weather Service (api.weather.gov) for Duncan (34.482, -97.961). Updated through the day.

Growing snapshot for Duncan

Last spring frost
Mar 25
First fall frost
Nov 7
Growing season
225 days
Hardiness zone
8a

More local growing data for Duncan: nearby ZIP 73533 weather · frost dates · planting calendar · Oklahoma frost dates

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Climate data from the nearest NOAA station, Duncan, Ok (5.3 mi from Duncan). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.