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

86°F

30°C

Humidity 77%
Wind Speed SE 6 mph
Barometer 29.93 in (1013.6 mb)
Dewpoint 78°F (26°C)
Visibility 10.00 mi
Heat Index98°F (37°C)
Last update 2 Aug 5:53 am EDT
Extended Forecast for

23 Miles NNW Long Key FL

  • Today

    Today: A 50 percent chance of showers and thunderstorms, mainly between 8am and 4pm. Partly sunny, with a high near 90. Heat index values as high as 103. South wind 5 to 7 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 90 °F

    Chance
    T-storms

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms before 9pm. Mostly cloudy, with a low around 79. Light and variable wind becoming southeast 5 to 7 mph after midnight.

    Low: 79 °F

    Slight Chance
    T-storms then
    Mostly Cloudy

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Partly sunny, with a high near 90. Heat index values as high as 103. South wind 6 to 8 mph.

    High: 90 °F

    Chance
    T-storms

  • Monday Night

    Monday Night: A 30 percent chance of showers and thunderstorms, mainly before 8pm. Mostly cloudy, with a low around 79. Light and variable wind.

    Low: 79 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: Showers and thunderstorms likely, mainly after 2pm. Partly sunny, with a high near 90. South wind 3 to 5 mph. Chance of precipitation is 60%.

    High: 90 °F

    Chance
    T-storms then
    T-storms
    Likely

  • Tuesday Night

    Tuesday Night: Showers and thunderstorms likely, mainly before 8pm. Mostly cloudy, with a low around 77. East wind around 6 mph. Chance of precipitation is 60%.

    Low: 77 °F

    T-storms
    Likely

  • Wednesday

    Wednesday: Showers and thunderstorms likely, mainly before 2pm. Mostly sunny, with a high near 89. East wind 6 to 10 mph. Chance of precipitation is 70%.

    High: 89 °F

    T-storms
    Likely

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 80. East wind around 14 mph, with gusts as high as 18 mph.

    Low: 80 °F

    Chance
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before 2pm, then showers and thunderstorms likely after 2pm. Mostly sunny, with a high near 88. East wind 13 to 15 mph, with gusts as high as 18 mph. Chance of precipitation is 70%.

    High: 88 °F

    Showers
    Likely then
    T-storms
    Likely

Detailed Forecast

Today
A 50 percent chance of showers and thunderstorms, mainly between 8am and 4pm. Partly sunny, with a high near 90. Heat index values as high as 103. South wind 5 to 7 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A 20 percent chance of showers and thunderstorms before 9pm. Mostly cloudy, with a low around 79. Light and variable wind becoming southeast 5 to 7 mph after midnight.
Monday
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Partly sunny, with a high near 90. Heat index values as high as 103. South wind 6 to 8 mph.
Monday Night
A 30 percent chance of showers and thunderstorms, mainly before 8pm. Mostly cloudy, with a low around 79. Light and variable wind.
Tuesday
Showers and thunderstorms likely, mainly after 2pm. Partly sunny, with a high near 90. South wind 3 to 5 mph. Chance of precipitation is 60%.
Tuesday Night
Showers and thunderstorms likely, mainly before 8pm. Mostly cloudy, with a low around 77. East wind around 6 mph. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms likely, mainly before 2pm. Mostly sunny, with a high near 89. East wind 6 to 10 mph. Chance of precipitation is 70%.
Wednesday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 80. East wind around 14 mph, with gusts as high as 18 mph.
Thursday
Showers likely and possibly a thunderstorm before 2pm, then showers and thunderstorms likely after 2pm. Mostly sunny, with a high near 88. East wind 13 to 15 mph, with gusts as high as 18 mph. Chance of precipitation is 70%.
Thursday Night
Showers and thunderstorms likely, mainly before 8pm. Partly cloudy, with a low around 79. Chance of precipitation is 60%.
Friday
Showers and thunderstorms likely. Mostly sunny, with a high near 87. Chance of precipitation is 70%.
Friday Night
Showers and thunderstorms likely. Partly cloudy, with a low around 79. Chance of precipitation is 60%.
Saturday
A 50 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
23 Miles NNW Long Key FL
 25.14°N 80.92°W
Last Update:
4:06 am EDT Aug 2, 2026
Forecast Valid:
6am 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