National Weather Service Forecast for: Duncan OK
Issued by: National Weather Service Norman, OK
Updated: 3:37 am CDT Jun 22, 2026
 
Overnight

Overnight: A 30 percent chance of showers and thunderstorms. Some of the storms could be severe. Partly cloudy, with a low around 76. Northeast wind around 9 mph.
Severe
T-Storms

 Monday

Monday: A chance of showers and thunderstorms before 7am, then showers likely and possibly a thunderstorm between 7am and 10am, then a chance of showers and thunderstorms after 10am. Partly sunny, with a high near 90. Heat index values as high as 100. East southeast wind 7 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Showers
Likely then
Chance
T-storms
 Monday
Night
Monday Night: A chance of showers and thunderstorms before 10pm, then showers likely and possibly a thunderstorm between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. East wind 7 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Showers
Likely

 Tuesday

Tuesday: A 30 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 92. Heat index values as high as 101. South wind 7 to 11 mph.
Chance
Showers

 Tuesday
Night
Tuesday Night: A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 75. South southeast wind 9 to 11 mph.
Mostly Clear
then Slight
Chance
T-storms
 Wednesday

Wednesday: Mostly sunny, with a high near 94.
Mostly Sunny

 Wednesday
Night
Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.
Slight Chance
T-storms

 Thursday

Thursday: Mostly sunny, with a high near 94.
Mostly Sunny

 Thursday
Night
Thursday Night: Partly cloudy, with a low around 76.
Partly Cloudy
Lo 76 °F Hi 90 °F Lo 72 °F Hi 92 °F Lo 75 °F Hi 94 °F Lo 74 °F Hi 94 °F Lo 76 °F

Severe Thunderstorm Watch
 

Overnight
 
 A 30 percent chance of showers and thunderstorms. Some of the storms could be severe. Partly cloudy, with a low around 76. Northeast wind around 9 mph.
Monday
 
 A chance of showers and thunderstorms before 7am, then showers likely and possibly a thunderstorm between 7am and 10am, then a chance of showers and thunderstorms after 10am. Partly sunny, with a high near 90. Heat index values as high as 100. East southeast wind 7 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday Night
 
 A chance of showers and thunderstorms before 10pm, then showers likely and possibly a thunderstorm between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. East wind 7 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday
 
 A 30 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 92. Heat index values as high as 101. South wind 7 to 11 mph.
Tuesday Night
 
 A 20 percent chance of showers and thunderstorms after 1am. Mostly clear, with a low around 75. South southeast wind 9 to 11 mph.
Wednesday
 
 Mostly sunny, with a high near 94.
Wednesday Night
 
 A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.
Thursday
 
 Mostly sunny, with a high near 94.
Thursday Night
 
 Partly cloudy, with a low around 76.
Friday
 
 Partly sunny and hot, with a high near 97.
Friday Night
 
 Mostly clear, with a low around 80.
Saturday
 
 Mostly sunny and hot, with a high near 100.
Saturday Night
 
 Mostly clear, with a low around 80.
Sunday
 
 Sunny and hot, with a high near 101. Windy.

 

Forecast from NOAA-NWS for Duncan OK.