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

88°F

31°C

Humidity 73%
Wind Speed SE 7 mph
Barometer 29.98 in (1015.0 mb)
Dewpoint 78°F (26°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 1 Sep 2:53 pm EDT
Extended Forecast for

30 Miles NNW Long Key FL

  • This Afternoon

    This Afternoon: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 88. Light south wind.

    High: 88 °F

    Chance
    T-storms

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 10pm. Mostly cloudy, with a low around 78. Light northeast wind.

    Low: 78 °F

    Chance
    T-storms then
    Partly Cloudy

  • Wednesday

    Wednesday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 89. Light and variable wind. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 89 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms before 9pm, then a slight chance of showers and thunderstorms after 2am. Partly cloudy, with a low around 79. Light and variable wind becoming east around 5 mph. Chance of precipitation is 20%.

    Low: 79 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: Showers and thunderstorms, mainly between 2pm and 5pm, then showers and possibly a thunderstorm after 5pm. High near 89. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 80%.

    High: 89 °F

    Chance
    T-storms then
    T-storms

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms, mainly after 2am. Low around 79. Southeast wind around 7 mph. Chance of precipitation is 80%.

    Low: 79 °F

    T-storms then
    Chance
    T-storms

  • Friday

    Friday: A chance of showers and thunderstorms before 8am, then showers and possibly a thunderstorm between 8am and 2pm, then showers and thunderstorms after 2pm. High near 88. Southeast wind 5 to 8 mph. Chance of precipitation is 80%.

    High: 88 °F

    T-storms

  • Friday Night

    Friday Night: Showers and thunderstorms, mainly before 8pm. Low around 78. East wind 3 to 6 mph. Chance of precipitation is 80%.

    Low: 78 °F

    T-storms then
    Chance
    T-storms

  • Saturday

    Saturday: Showers likely and possibly a thunderstorm, then showers and thunderstorms after 2pm. High near 89. Light southeast wind. Chance of precipitation is 80%.

    High: 89 °F

    Showers
    Likely then
    T-storms

Detailed Forecast

This Afternoon
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 88. Light south wind.
Tonight
A 30 percent chance of showers and thunderstorms, mainly before 10pm. Mostly cloudy, with a low around 78. Light northeast wind.
Wednesday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 89. Light and variable wind. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
A slight chance of showers and thunderstorms before 9pm, then a slight chance of showers and thunderstorms after 2am. Partly cloudy, with a low around 79. Light and variable wind becoming east around 5 mph. Chance of precipitation is 20%.
Thursday
Showers and thunderstorms, mainly between 2pm and 5pm, then showers and possibly a thunderstorm after 5pm. High near 89. Calm wind becoming south around 5 mph in the afternoon. Chance of precipitation is 80%.
Thursday Night
Showers and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms, mainly after 2am. Low around 79. Southeast wind around 7 mph. Chance of precipitation is 80%.
Friday
A chance of showers and thunderstorms before 8am, then showers and possibly a thunderstorm between 8am and 2pm, then showers and thunderstorms after 2pm. High near 88. Southeast wind 5 to 8 mph. Chance of precipitation is 80%.
Friday Night
Showers and thunderstorms, mainly before 8pm. Low around 78. East wind 3 to 6 mph. Chance of precipitation is 80%.
Saturday
Showers likely and possibly a thunderstorm, then showers and thunderstorms after 2pm. High near 89. Light southeast wind. Chance of precipitation is 80%.
Saturday Night
Showers and thunderstorms, mainly before 8pm. Low around 78. Chance of precipitation is 80%.
Sunday
Showers and thunderstorms likely. Mostly sunny, with a high near 89. Chance of precipitation is 70%.
Sunday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 78. Chance of precipitation is 60%.
Labor Day
Showers and thunderstorms likely. Partly sunny, with a high near 88. Chance of precipitation is 60%.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
30 Miles NNW Long Key FL
 25.22°N 81.01°W
Last Update:
2:31 pm EDT Sep 1, 2026
Forecast Valid:
3pm EDT Sep 1, 2026-6pm EDT Sep 7, 2026
 
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