Duncan, OK Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Duncan, a city in Stephens County, Oklahoma.
Tonight
74°F
Mostly Clear
Mostly clear, with a low around 74. Heat index values as high as 97. South southeast wind 8 to 13 mph, with gusts as high as 20 mph.
7-day forecast for Duncan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 74°F | Mostly Clear | 8 to 13 mph SSE | 0% |
| Saturday | 99°F | Sunny | 8 to 13 mph S | 1% |
| Saturday Night | 75°F | Mostly Clear | 9 to 13 mph S | 11% |
| Sunday | 98°F | Showers And Thunderstorms Likely | 9 to 13 mph S | 59% |
| Sunday Night | 67°F | Showers And Thunderstorms Likely | 5 to 9 mph ESE | 68% |
| Monday | 91°F | Chance Rain Showers | 6 to 9 mph NE | 35% |
| Monday Night | 65°F | Mostly Clear then Slight Chance Rain Showers | 10 mph NE | 15% |
| Tuesday | 87°F | Slight Chance Rain Showers then Mostly Sunny | 13 mph NE | 15% |
| Tuesday Night | 63°F | Partly Cloudy | 9 to 13 mph NE | 7% |
| Wednesday | 88°F | Mostly Sunny | 10 mph ENE | 12% |
| Wednesday Night | 64°F | Partly Cloudy | 9 mph ENE | 5% |
| Thursday | 89°F | Slight Chance Rain Showers | 8 mph E | 20% |
| Thursday Night | 66°F | Partly Cloudy | 9 mph ENE | 8% |
| Friday | 90°F | Partly Sunny | 9 mph ESE | 10% |
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
Nearby towns & communities
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 Sep 19, 2026.