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

91°F

33°C

Humidity 57%
Wind Speed Calm
Barometer 29.90 in (1012.5 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index100°F (38°C)
Last update 18 Aug 2:53 pm EDT
Extended Forecast for

27 Miles NW Long Key FL

  • This Afternoon

    This Afternoon: Sunny, with a high near 88. Heat index values as high as 100. West wind around 6 mph.

    High: 88 °F

    Sunny

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 10pm. Mostly clear, with a low around 80. Northwest wind 5 to 7 mph becoming northeast after midnight.

    Low: 80 °F

    Chance
    T-storms then
    Mostly Clear

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms, mainly after 3pm. Sunny, with a high near 89. Heat index values as high as 100. North wind 7 to 11 mph.

    High: 89 °F

    Sunny then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 50 percent chance of showers and thunderstorms, mainly before 2am. Partly cloudy, with a low around 81. Northwest wind 8 to 11 mph.

    Low: 81 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly after 8am. Mostly sunny, with a high near 88. West wind 8 to 15 mph, with gusts as high as 21 mph.

    High: 88 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly clear, with a low around 82. West wind 10 to 14 mph.

    Low: 82 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms. Sunny, with a high near 87. West wind 10 to 14 mph, with gusts as high as 18 mph.

    High: 87 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 81. West wind 6 to 10 mph.

    Low: 81 °F

    Slight Chance
    T-storms

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms. Sunny, with a high near 88. West wind 6 to 9 mph.

    High: 88 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
Sunny, with a high near 88. Heat index values as high as 100. West wind around 6 mph.
Tonight
A 30 percent chance of showers and thunderstorms, mainly before 10pm. Mostly clear, with a low around 80. Northwest wind 5 to 7 mph becoming northeast after midnight.
Tuesday
A 30 percent chance of showers and thunderstorms, mainly after 3pm. Sunny, with a high near 89. Heat index values as high as 100. North wind 7 to 11 mph.
Tuesday Night
A 50 percent chance of showers and thunderstorms, mainly before 2am. Partly cloudy, with a low around 81. Northwest wind 8 to 11 mph.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly after 8am. Mostly sunny, with a high near 88. West wind 8 to 15 mph, with gusts as high as 21 mph.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly clear, with a low around 82. West wind 10 to 14 mph.
Thursday
A 40 percent chance of showers and thunderstorms. Sunny, with a high near 87. West wind 10 to 14 mph, with gusts as high as 18 mph.
Thursday Night
A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 81. West wind 6 to 10 mph.
Friday
A 30 percent chance of showers and thunderstorms. Sunny, with a high near 88. West wind 6 to 9 mph.
Friday Night
A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 80.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 88.
Saturday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 81.
Sunday
A 30 percent chance of showers and thunderstorms. Sunny, with a high near 88.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
27 Miles NW Long Key FL
 25.13°N 81.08°W
Last Update:
2:36 pm EDT Aug 18, 2025
Forecast Valid:
3pm EDT Aug 18, 2025-6pm EDT Aug 24, 2025
 
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Additional Resources

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