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

Dangerous Heat over the South-Central and Southwest U.S. Through Next Week

Dangerous heat persists across the Desert Southwest through this weekend and across the Southern Plains and Lower Mississippi Valley through at least the middle of next week. Numerous daily record high temperatures are expected through at least Tuesday for much of Texas and Oklahoma as well as portions of Louisiana, New Mexico, and Arizona. Read More >

Current conditions at

The Florida Keys - Marathon International Airport (KMTH)

Lat: 24.73°NLon: 81.05°WElev: 13ft.

Fair

89°F

32°C

Humidity 68%
Wind Speed S 8 mph
Barometer 30.03 in (1016.9 mb)
Dewpoint 77°F (25°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 22 Aug 1:53 pm EDT
Extended Forecast for

Marathon FLSimilar City Names

  • This Afternoon

    This Afternoon: A slight chance of showers and thunderstorms. Sunny, with a high near 90. Southeast wind around 5 mph. Chance of precipitation is 10%.

    High: 90 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 83. Southeast wind around 5 mph. Chance of precipitation is 20%.

    Low: 83 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: A slight chance of showers and thunderstorms. Mostly sunny, with a high near 90. Southeast wind around 5 mph. Chance of precipitation is 20%.

    High: 90 °F

    Slight Chance
    T-storms

  • Sunday Night

    Sunday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 82. Southeast wind around 10 mph. Chance of precipitation is 20%.

    Low: 82 °F

    Slight Chance
    T-storms

  • Monday

    Monday: Sunny, with a high near 90. East wind around 10 mph.

    High: 90 °F

    Sunny

  • Monday Night

    Monday Night: A chance of showers and thunderstorms. Mostly clear, with a low around 83. Chance of precipitation is 30%.

    Low: 83 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A slight chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 20%.

    High: 91 °F

    Slight Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 50%.

    Low: 82 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A slight chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 20%.

    High: 91 °F

    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
A slight chance of showers and thunderstorms. Sunny, with a high near 90. Southeast wind around 5 mph. Chance of precipitation is 10%.
Tonight
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 83. Southeast wind around 5 mph. Chance of precipitation is 20%.
Sunday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 90. Southeast wind around 5 mph. Chance of precipitation is 20%.
Sunday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 82. Southeast wind around 10 mph. Chance of precipitation is 20%.
Monday
Sunny, with a high near 90. East wind around 10 mph.
Monday Night
A chance of showers and thunderstorms. Mostly clear, with a low around 83. Chance of precipitation is 30%.
Tuesday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 20%.
Tuesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 50%.
Wednesday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 20%.
Wednesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 50%.
Thursday
A chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 30%.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 83. Chance of precipitation is 50%.
Friday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 20%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Marathon FLSimilar City Names
 24.72°N 81.07°W (Elev. 7 ft)
Last Update:
2:15 pm EDT Aug 22, 2026
Forecast Valid:
2pm EDT Aug 22, 2026-6pm EDT Aug 28, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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