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.

Mostly Cloudy

79°F

26°C

Humidity 72%
Wind Speed Calm
Barometer 29.94 in (1013.9 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 15 May 3:53 am EDT
Extended Forecast for

Long Key FL

  • Today

    Today: Sunny, with a high near 85. Northwest wind 5 to 10 mph becoming west in the afternoon.

    High: 85 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 80. Calm wind becoming southeast around 5 mph after midnight.

    Low: 80 °F

    Mostly Clear

  • Saturday

    Saturday: A slight chance of showers and thunderstorms. Mostly sunny, with a high near 85. East wind around 10 mph. Chance of precipitation is 20%.

    High: 85 °F

    Slight Chance
    T-storms

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 80. East wind 10 to 15 mph. Chance of precipitation is 40%.

    Low: 80 °F

    Chance
    Showers

  • Sunday

    Sunday: A chance of showers and thunderstorms. Mostly sunny, with a high near 85. East wind around 10 mph. Chance of precipitation is 40%.

    High: 85 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 81. Chance of precipitation is 40%.

    Low: 81 °F

    Chance
    Showers

  • Monday

    Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 85. Chance of precipitation is 40%.

    High: 85 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 81. Breezy. Chance of precipitation is 20%.

    Low: 81 °F

    Slight Chance
    T-storms and
    Breezy

  • Tuesday

    Tuesday: A slight chance of showers and thunderstorms. Sunny, with a high near 85. Chance of precipitation is 20%.

    High: 85 °F

    Slight Chance
    T-storms

Detailed Forecast

Today
Sunny, with a high near 85. Northwest wind 5 to 10 mph becoming west in the afternoon.
Tonight
Mostly clear, with a low around 80. Calm wind becoming southeast around 5 mph after midnight.
Saturday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 85. East wind around 10 mph. Chance of precipitation is 20%.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 80. East wind 10 to 15 mph. Chance of precipitation is 40%.
Sunday
A chance of showers and thunderstorms. Mostly sunny, with a high near 85. East wind around 10 mph. Chance of precipitation is 40%.
Sunday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 81. Chance of precipitation is 40%.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 85. Chance of precipitation is 40%.
Monday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 81. Breezy. Chance of precipitation is 20%.
Tuesday
A slight chance of showers and thunderstorms. Sunny, with a high near 85. Chance of precipitation is 20%.
Tuesday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 81. Breezy. Chance of precipitation is 20%.
Wednesday
A slight chance of showers and thunderstorms. Sunny, with a high near 85. Chance of precipitation is 20%.
Wednesday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 81. Chance of precipitation is 20%.
Thursday
A slight chance of showers. Sunny, with a high near 86. Chance of precipitation is 10%.
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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 May 15, 2026
Forecast Valid:
4am EDT May 15, 2026-6pm EDT May 21, 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