National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Areas of Extreme Heat and Excessive Rainfall Potential

Dangerous and extreme heat will remain across portions of the central U.S. this week, persisting across the mid to lower Mississippi Valley, Gulf Coast, southern Plains and portions of Texas. A heat wave over the Southwest U.S. will peak this weekend. Heavy to excessive rainfall may produce flash flooding from the Delmarva Peninsula north into the Hudson Valley today and tonight. Read More >

Hazardous Weather Conditions

Current conditions at

Sherman/Denison, Grayson County Airport (KGYI)

Lat: 33.72°NLon: 96.67°WElev: 748ft.

Fair

99°F

37°C

Humidity 37%
Wind Speed SE 12 mph
Barometer 29.83 in
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index105°F (41°C)
Last update 28 Jul 5:50 pm CDT
Extended Forecast for

Denison TX

Heat Advisory July 28, 06:39pm until July 29, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory July 28, 06:39pm until July 29, 08:00pm

    NOW until 8:00pm Wed

    Heat Advisory

  • Tonight

    Low: 80 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny and hot, with a high near 101. Heat index values as high as 109. South wind around 5 mph.

    High: 101 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 80. South wind around 5 mph.

    Low: 80 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny and hot, with a high near 101. Heat index values as high as 109. South wind around 5 mph.

    High: 101 °F

    Hot

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 80. South southeast wind around 5 mph.

    Low: 80 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny and hot, with a high near 103. Southwest wind 5 to 10 mph.

    High: 103 °F

    Hot

  • Friday Night

    Friday Night: Partly cloudy, with a low around 80. South southwest wind around 5 mph becoming north northwest after midnight.

    Low: 80 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 97. North wind around 10 mph.

    High: 97 °F

    Sunny

Detailed Forecast

Tonight
Partly cloudy, with a low around 80. South wind 5 to 10 mph.
Wednesday
Mostly sunny and hot, with a high near 101. Heat index values as high as 109. South wind around 5 mph.
Wednesday Night
Mostly clear, with a low around 80. South wind around 5 mph.
Thursday
Mostly sunny and hot, with a high near 101. Heat index values as high as 109. South wind around 5 mph.
Thursday Night
Partly cloudy, with a low around 80. South southeast wind around 5 mph.
Friday
Mostly sunny and hot, with a high near 103. Southwest wind 5 to 10 mph.
Friday Night
Partly cloudy, with a low around 80. South southwest wind around 5 mph becoming north northwest after midnight.
Saturday
Sunny, with a high near 97. North wind around 10 mph.
Saturday Night
Mostly clear, with a low around 72. North northeast wind 5 to 10 mph.
Sunday
Sunny, with a high near 95.
Sunday Night
Clear, with a low around 73.
Monday
Sunny, with a high near 97.
Monday Night
Mostly clear, with a low around 76.
Tuesday
Sunny and hot, with a high near 99.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Denison TX
 33.75°N 96.55°W (Elev. 758 ft)
Last Update:
6:11 pm CDT Jul 28, 2026
Forecast Valid:
6pm CDT Jul 28, 2026-6pm CDT Aug 4, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation