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.

Partly Cloudy

90°F

32°C

Humidity 59%
Wind Speed Calm
Barometer 30.08 in (1018.5 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index99°F (37°C)
Last update 13 Jul 3:53 pm EDT
Extended Forecast for

Long Key FL

  • This Afternoon

    This Afternoon: Showers likely and possibly a thunderstorm. Mostly sunny, with a high near 87. Calm wind. Chance of precipitation is 60%.

    High: 87 °F

    Showers
    Likely

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms after 8pm. Mostly cloudy, with a low around 79. Calm wind becoming northeast around 5 mph. Chance of precipitation is 60%.

    Low: 79 °F

    Showers
    Likely

  • Monday

    Monday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 85. Southwest wind around 5 mph. Chance of precipitation is 70%.

    High: 85 °F

    Showers
    Likely

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 78. North wind around 5 mph becoming south after midnight. Chance of precipitation is 70%.

    Low: 78 °F

    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 85. South wind around 5 mph. Chance of precipitation is 60%.

    High: 85 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 81. Chance of precipitation is 50%.

    Low: 81 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers and thunderstorms. Partly sunny, with a high near 86. Chance of precipitation is 50%.

    High: 86 °F

    Chance
    T-storms

  • Wednesday Night

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

    Low: 82 °F

    Chance
    Showers

  • Thursday

    Thursday: A chance of showers and thunderstorms. Partly sunny, with a high near 86. Chance of precipitation is 40%.

    High: 86 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Showers likely and possibly a thunderstorm. Mostly sunny, with a high near 87. Calm wind. Chance of precipitation is 60%.
Tonight
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms after 8pm. Mostly cloudy, with a low around 79. Calm wind becoming northeast around 5 mph. Chance of precipitation is 60%.
Monday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 85. Southwest wind around 5 mph. Chance of precipitation is 70%.
Monday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 78. North wind around 5 mph becoming south after midnight. Chance of precipitation is 70%.
Tuesday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 85. South wind around 5 mph. Chance of precipitation is 60%.
Tuesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 81. Chance of precipitation is 50%.
Wednesday
A chance of showers and thunderstorms. Partly sunny, with a high near 86. Chance of precipitation is 50%.
Wednesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 82. Chance of precipitation is 40%.
Thursday
A chance of showers and thunderstorms. Partly sunny, with a high near 86. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 30%.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 87. Chance of precipitation is 30%.
Friday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 82. Chance of precipitation is 30%.
Saturday
A chance of showers and thunderstorms. Sunny, with a high near 87. Chance of precipitation is 30%.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Long Key FL
 24.83°N 80.81°W (Elev. 0 ft)
Last Update:
4:15 pm EDT Jul 13, 2025
Forecast Valid:
4pm EDT Jul 13, 2025-6pm EDT Jul 19, 2025
 
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