National Weather Service Forecast for: Duncan OK
Issued by: National Weather Service Norman, OK
Updated: 9:32 pm CDT Jun 18, 2026
 
Tonight

Tonight: Showers and possibly a thunderstorm. Low around 67. Northeast wind 10 to 14 mph, with gusts as high as 21 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Showers

 Juneteenth

Juneteenth: Showers likely, mainly before 7am. Mostly cloudy, with a high near 84. East northeast wind 8 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Showers
Likely then
Chance
Showers
 Friday
Night
Friday Night: A 40 percent chance of showers and thunderstorms. Increasing clouds, with a low around 70. East southeast wind 5 to 9 mph.
Chance
T-storms

 Saturday

Saturday: A 20 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 88. South southeast wind 5 to 9 mph.
Slight Chance
T-storms

 Saturday
Night
Saturday Night: Partly cloudy, with a low around 74. South southeast wind 10 to 13 mph, with gusts as high as 20 mph.
Partly Cloudy

 Sunday

Sunday: Mostly sunny and hot, with a high near 98.
Hot

 Sunday
Night
Sunday Night: A chance of showers, with thunderstorms also possible after 1am. Mostly clear, with a low around 75. Chance of precipitation is 50%.
Chance
Showers then
Chance
T-storms
 Monday

Monday: A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 90.
Chance
T-storms

 Monday
Night
Monday Night: Showers and thunderstorms likely before 1am, then showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 70. Chance of precipitation is 70%.
T-storms
Likely
Lo 67 °F Hi 84 °F Lo 70 °F Hi 88 °F Lo 74 °F Hi 98 °F Lo 75 °F Hi 90 °F Lo 70 °F

Flood Watch
 

Tonight
 
 Showers and possibly a thunderstorm. Low around 67. Northeast wind 10 to 14 mph, with gusts as high as 21 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Juneteenth
 
 Showers likely, mainly before 7am. Mostly cloudy, with a high near 84. East northeast wind 8 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
 
 A 40 percent chance of showers and thunderstorms. Increasing clouds, with a low around 70. East southeast wind 5 to 9 mph.
Saturday
 
 A 20 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 88. South southeast wind 5 to 9 mph.
Saturday Night
 
 Partly cloudy, with a low around 74. South southeast wind 10 to 13 mph, with gusts as high as 20 mph.
Sunday
 
 Mostly sunny and hot, with a high near 98.
Sunday Night
 
 A chance of showers, with thunderstorms also possible after 1am. Mostly clear, with a low around 75. Chance of precipitation is 50%.
Monday
 
 A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 90.
Monday Night
 
 Showers and thunderstorms likely before 1am, then showers likely and possibly a thunderstorm after 1am. Partly cloudy, with a low around 70. Chance of precipitation is 70%.
Tuesday
 
 A 40 percent chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 88.
Tuesday Night
 
 A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 71.
Wednesday
 
 A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 89.
Wednesday Night
 
 A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 71.
Thursday
 
 A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 91.

 

Forecast from NOAA-NWS for Duncan OK.