National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Tracking Late Season Winter Storms; Unusual Early-Season Heat Wave in the Southwest

Heavy snow and high winds continue in the Great Lakes and Northeast. A moderate atmospheric river will continue to bring heavy precipitation to the Pacific Northwest and northern Rockies. A major winter storm will develop across the northern High Plains tonight into Saturday and rapidly strengthen as it moves into the Great Lakes on Sunday. Above-average temperatures expected in the Southwest. Read More >

Current conditions at

The Florida Keys - Marathon International Airport (KMTH)

Lat: 24.73°NLon: 81.05°WElev: 13ft.

A Few Clouds

81°F

27°C

Humidity 72%
Wind Speed S 7 mph
Barometer 29.96 in (1014.5 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index85°F (29°C)
Last update 13 Mar 3:53 pm EDT
Extended Forecast for

Long Key FL

  • This Afternoon

    This Afternoon: A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Southeast wind around 5 mph. Chance of precipitation is 30%.

    High: 80 °F

    Chance
    Showers

  • Tonight

    Tonight: A chance of showers and thunderstorms. Partly cloudy, with a low around 74. Southeast wind around 5 mph. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    Showers

  • Saturday

    Saturday: A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Southeast wind around 10 mph. Chance of precipitation is 50%.

    High: 80 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 75. East wind 10 to 15 mph. Chance of precipitation is 50%.

    Low: 75 °F

    Chance
    Showers

  • Sunday

    Sunday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 80. Southeast wind around 15 mph. Chance of precipitation is 60%.

    High: 80 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Chance of precipitation is 50%.

    Low: 75 °F

    Chance
    Showers

  • Monday

    Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Chance of precipitation is 50%.

    High: 80 °F

    Chance
    Showers

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 68. Chance of precipitation is 70%.

    Low: 68 °F

    Showers
    Likely

  • Tuesday

    Tuesday: A chance of showers and thunderstorms. Cloudy, with a high near 73. Windy. Chance of precipitation is 50%.

    High: 73 °F

    Chance
    Showers and
    Windy

Detailed Forecast

This Afternoon
A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Southeast wind around 5 mph. Chance of precipitation is 30%.
Tonight
A chance of showers and thunderstorms. Partly cloudy, with a low around 74. Southeast wind around 5 mph. Chance of precipitation is 30%.
Saturday
A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Southeast wind around 10 mph. Chance of precipitation is 50%.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 75. East wind 10 to 15 mph. Chance of precipitation is 50%.
Sunday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 80. Southeast wind around 15 mph. Chance of precipitation is 60%.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Chance of precipitation is 50%.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 80. Chance of precipitation is 50%.
Monday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 68. Chance of precipitation is 70%.
Tuesday
A chance of showers and thunderstorms. Cloudy, with a high near 73. Windy. Chance of precipitation is 50%.
Tuesday Night
Showers likely and possibly a thunderstorm. Cloudy, with a low around 63. Windy. Chance of precipitation is 60%.
Wednesday
Showers likely and possibly a thunderstorm. Cloudy, with a high near 71. Windy. Chance of precipitation is 60%.
Wednesday Night
A chance of showers and thunderstorms. Cloudy, with a low around 66. Windy. Chance of precipitation is 40%.
Thursday
A chance of showers. Partly sunny, with a high near 74. Windy. Chance of precipitation is 30%.
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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 Mar 13, 2026
Forecast Valid:
4pm EDT Mar 13, 2026-6pm EDT Mar 19, 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