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

Extreme Heat Lingers; Severe Thunderstorms for Portions of the Plains and Southeast; Heavy Rainfall Threats

Gusty winds and heavy rainfall may impact the Big Island of Hawaii as a nearby tropical system passes west of the islands. From the Southwest U.S., Rockies and across the Gulf Coast, heavy rainfall could lead to isolated flash flooding. Severe thunderstorms are expected for areas of the Plains, Gulf Coast and Southeast through Tuesday. Extreme heat lingers for the southern Plains and Southwest. Read More >

Hazardous Weather Conditions

Current conditions at

Sherman/Denison, Grayson County Airport (KGYI)

Lat: 33.72°NLon: 96.67°WElev: 748ft.

Fair

100°F

38°C

Humidity 25%
Wind Speed SW 13 mph
Barometer 29.95 in
Dewpoint 59°F (15°C)
Visibility 9.00 mi
Heat Index100°F (38°C)
Last update 24 Aug 12:50 pm CDT
Extended Forecast for

3 Miles ENE Knollwood TX

Extreme Heat Warning August 24, 12:57pm until August 24, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning August 24, 12:57pm until August 24, 09:00pm

    NOW until 9:00pm Mon

    Extreme Heat Warning

  • This Afternoon

    High: 107 °F

    Hot

  • Tonight

    Tonight: Mostly clear, with a low around 83. South wind around 10 mph.

    Low: 83 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny and hot, with a high near 106. South southwest wind 10 to 15 mph.

    High: 106 °F

    Hot

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 80. South southwest wind 5 to 10 mph.

    Low: 80 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny and hot, with a high near 100. South southwest wind around 5 mph becoming north northwest in the afternoon.

    High: 100 °F

    Hot

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 76. Northwest wind around 5 mph becoming calm after midnight.

    Low: 76 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny and hot, with a high near 99. Northeast wind around 5 mph.

    High: 99 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 75. East northeast wind around 5 mph.

    Low: 75 °F

    Mostly Clear

Detailed Forecast

This Afternoon
Mostly sunny and hot, with a high near 107. Southwest wind 10 to 15 mph, with gusts as high as 20 mph.
Tonight
Mostly clear, with a low around 83. South wind around 10 mph.
Tuesday
Mostly sunny and hot, with a high near 106. South southwest wind 10 to 15 mph.
Tuesday Night
Mostly clear, with a low around 80. South southwest wind 5 to 10 mph.
Wednesday
Mostly sunny and hot, with a high near 100. South southwest wind around 5 mph becoming north northwest in the afternoon.
Wednesday Night
Partly cloudy, with a low around 76. Northwest wind around 5 mph becoming calm after midnight.
Thursday
Mostly sunny and hot, with a high near 99. Northeast wind around 5 mph.
Thursday Night
Mostly clear, with a low around 75. East northeast wind around 5 mph.
Friday
Sunny and hot, with a high near 99. Southeast wind around 5 mph.
Friday Night
Mostly clear, with a low around 77.
Saturday
Sunny and hot, with a high near 100.
Saturday Night
Clear, with a low around 79.
Sunday
Sunny and hot, with a high near 101.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles ENE Knollwood TX
 33.71°N 96.57°W (Elev. 673 ft)
Last Update:
6:12 am CDT Aug 24, 2026
Forecast Valid:
12pm CDT Aug 24, 2026-6pm CDT Aug 30, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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