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

Dangerous Heat and Possible Flooding

Dangerous heat will persist across the Southwest U.S. through Saturday with daytime highs of 110-115°F. Extreme Heat Warnings remain in effect. Dangerous heat will build across the southern Plains again beginning this weekend. Heavy to excessive rain over the Carolinas Friday may lead to isolated areas of flash flooding. Read More >

Hazardous Weather Conditions

Current conditions at

The Florida Keys - Marathon International Airport (KMTH)

Lat: 24.73°NLon: 81.05°WElev: 13ft.

A Few Clouds

86°F

30°C

Humidity 75%
Wind Speed E 7 mph
Barometer 29.98 in (1015.1 mb)
Dewpoint 77°F (25°C)
Visibility 10.00 mi
Heat Index97°F (36°C)
Last update 29 Aug 3:53 am EDT
Extended Forecast for

Marathon FLSimilar City Names

  • Overnight

    Overnight: A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 30%.

    Low: 83 °F

    Chance
    T-storms

  • Saturday

    Saturday: A chance of showers and thunderstorms. Mostly sunny, with a high near 90. East wind around 10 mph. Chance of precipitation is 50%.

    High: 90 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 50%.

    Low: 83 °F

    Chance
    T-storms

  • Sunday

    Sunday: A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Southeast wind 5 to 10 mph. Chance of precipitation is 50%.

    High: 90 °F

    Chance
    T-storms

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 40%.

    Low: 83 °F

    Chance
    T-storms

  • Monday

    Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 40%.

    High: 91 °F

    Chance
    T-storms

  • Monday Night

    Monday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 40%.

    Low: 82 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Chance of precipitation is 50%.

    High: 90 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Showers and thunderstorms likely. Partly cloudy, with a low around 83. Chance of precipitation is 60%.

    Low: 83 °F

    T-storms
    Likely

Detailed Forecast

Overnight
A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 30%.
Saturday
A chance of showers and thunderstorms. Mostly sunny, with a high near 90. East wind around 10 mph. Chance of precipitation is 50%.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 50%.
Sunday
A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Southeast wind 5 to 10 mph. Chance of precipitation is 50%.
Sunday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 83. East wind around 10 mph. Chance of precipitation is 40%.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 91. Chance of precipitation is 40%.
Monday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 40%.
Tuesday
A chance of showers and thunderstorms. Mostly sunny, with a high near 90. Chance of precipitation is 50%.
Tuesday Night
Showers and thunderstorms likely. Partly cloudy, with a low around 83. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms likely. Mostly sunny, with a high near 90. Chance of precipitation is 70%.
Wednesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 82. Chance of precipitation is 70%.
Thursday
Showers and thunderstorms likely. Partly sunny, with a high near 90. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 82. Chance of precipitation is 60%.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 89. Chance of precipitation is 50%.
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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:
4:21 am EDT Aug 29, 2026
Forecast Valid:
4am EDT Aug 29, 2026-6pm EDT Sep 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