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.

Fair

90°F

32°C

Humidity 66%
Wind Speed E 8 mph
Barometer 30.07 in (1018.2 mb)
Dewpoint 77°F (25°C)
Visibility 10.00 mi
Heat Index103°F (39°C)
Last update 7 Jul 4:53 pm EDT
Extended Forecast for

25 Miles NNW Long Key FL

  • This Afternoon

    This Afternoon: A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 89. Heat index values as high as 102. East wind around 9 mph.

    High: 89 °F

    Chance
    T-storms

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms before 7pm. Partly cloudy, with a low around 81. East wind around 9 mph.

    Low: 81 °F

    Chance
    T-storms then
    Partly Cloudy

  • Wednesday

    Wednesday: A slight chance of showers and thunderstorms before 9am, then a slight chance of showers and thunderstorms after 11am. Mostly sunny, with a high near 89. Heat index values as high as 103. Southeast wind 8 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    High: 89 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 82. East wind around 14 mph, with gusts as high as 18 mph.

    Low: 82 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 90. Breezy, with an east wind 13 to 17 mph, with gusts as high as 22 mph.

    High: 90 °F

    Mostly Sunny
    then Sunny
    and Breezy

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 81. Breezy, with an east wind 14 to 16 mph, with gusts as high as 21 mph.

    Low: 81 °F

    Slight Chance
    T-storms and
    Breezy

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89. Breezy, with an east wind 14 to 18 mph, with gusts as high as 22 mph.

    High: 89 °F

    Chance
    T-storms and
    Breezy

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 81. Breezy, with an east wind 13 to 16 mph, with gusts as high as 21 mph.

    Low: 81 °F

    Chance
    T-storms and
    Breezy

  • Saturday

    Saturday: A slight chance of showers and thunderstorms between 8am and 2pm. Mostly sunny, with a high near 89. Southeast wind 11 to 14 mph. Chance of precipitation is 20%.

    High: 89 °F

    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 89. Heat index values as high as 102. East wind around 9 mph.
Tonight
A 30 percent chance of showers and thunderstorms before 7pm. Partly cloudy, with a low around 81. East wind around 9 mph.
Wednesday
A slight chance of showers and thunderstorms before 9am, then a slight chance of showers and thunderstorms after 11am. Mostly sunny, with a high near 89. Heat index values as high as 103. Southeast wind 8 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Wednesday Night
Partly cloudy, with a low around 82. East wind around 14 mph, with gusts as high as 18 mph.
Thursday
Mostly sunny, with a high near 90. Breezy, with an east wind 13 to 17 mph, with gusts as high as 22 mph.
Thursday Night
A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 81. Breezy, with an east wind 14 to 16 mph, with gusts as high as 21 mph.
Friday
A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89. Breezy, with an east wind 14 to 18 mph, with gusts as high as 22 mph.
Friday Night
A 40 percent chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 81. Breezy, with an east wind 13 to 16 mph, with gusts as high as 21 mph.
Saturday
A slight chance of showers and thunderstorms between 8am and 2pm. Mostly sunny, with a high near 89. Southeast wind 11 to 14 mph. Chance of precipitation is 20%.
Saturday Night
Partly cloudy, with a low around 81.
Sunday
Mostly sunny, with a high near 89.
Sunday Night
Mostly clear, with a low around 81.
Monday
Sunny, with a high near 90.
Monday Night
Mostly clear, with a low around 81.
Tuesday
A slight chance of showers and thunderstorms. Sunny, with a high near 90.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
25 Miles NNW Long Key FL
 25.17°N 80.94°W
Last Update:
4:48 pm EDT Jul 7, 2026
Forecast Valid:
5pm EDT Jul 7, 2026-6pm EDT Jul 14, 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