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

The Florida Keys - Marathon International Airport (KMTH)

Lat: 24.73°NLon: 81.05°WElev: 13ft.

A Few Clouds

85°F

29°C

Humidity 77%
Wind Speed SE 7 mph
Barometer 29.92 in (1013.0 mb)
Dewpoint 77°F (25°C)
Visibility 10.00 mi
Heat Index96°F (36°C)
Last update 2 Aug 3:53 am EDT
Extended Forecast for

Long Key FL

  • Overnight

    Overnight: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Southeast wind 5 to 10 mph. Chance of precipitation is 20%.

    Low: 83 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: A slight chance of showers and thunderstorms. Partly sunny, with a high near 89. Southeast wind around 5 mph. Chance of precipitation is 20%.

    High: 89 °F

    Slight Chance
    T-storms

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 84. East wind 5 to 10 mph. Chance of precipitation is 30%.

    Low: 84 °F

    Chance
    Showers

  • Monday

    Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 89. South wind around 5 mph. Chance of precipitation is 30%.

    High: 89 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 30%.

    Low: 83 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers and thunderstorms. Mostly sunny, with a high near 88. Chance of precipitation is 40%.

    High: 88 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Chance of precipitation is 50%.

    Low: 83 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Showers and thunderstorms likely. Mostly sunny, with a high near 88. Chance of precipitation is 60%.

    High: 88 °F

    T-storms
    Likely

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 83. Chance of precipitation is 50%.

    Low: 83 °F

    Chance
    T-storms

Detailed Forecast

Overnight
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Southeast wind 5 to 10 mph. Chance of precipitation is 20%.
Sunday
A slight chance of showers and thunderstorms. Partly sunny, with a high near 89. Southeast wind around 5 mph. Chance of precipitation is 20%.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 84. East wind 5 to 10 mph. Chance of precipitation is 30%.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 89. South wind around 5 mph. Chance of precipitation is 30%.
Monday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 30%.
Tuesday
A chance of showers and thunderstorms. Mostly sunny, with a high near 88. Chance of precipitation is 40%.
Tuesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 83. Chance of precipitation is 50%.
Wednesday
Showers and thunderstorms likely. Mostly sunny, with a high near 88. Chance of precipitation is 60%.
Wednesday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 83. Chance of precipitation is 50%.
Thursday
Showers likely and possibly a thunderstorm. Mostly sunny, with a high near 88. Chance of precipitation is 60%.
Thursday Night
Showers likely and possibly a thunderstorm. Partly cloudy, with a low around 82. Breezy. Chance of precipitation is 60%.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 88. Chance of precipitation is 50%.
Friday Night
Showers likely and possibly a thunderstorm. Partly cloudy, with a low around 83. Chance of precipitation is 60%.
Saturday
A chance of showers and thunderstorms. Mostly sunny, with a high near 88. Chance of precipitation is 30%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Long Key FL
 24.83°N 80.81°W (Elev. 0 ft)
Last Update:
4:15 am EDT Aug 2, 2026
Forecast Valid:
4am EDT Aug 2, 2026-6pm EDT Aug 8, 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