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

Tracking a Winter Storm; Unusual Early-Season Heat Wave in the Southwest

A major winter storm will organize across the Northern Plains today and then rapidly strengthen as it moves into the Great Lakes on Sunday. Heavy snow and blowing snow are likely to persist over the Great Lakes into Monday night. Dry and gusty winds will produce a critical fire risk across the central/southern Plains. An early heatwave will begin to intensify over the western U.S. into next week. Read More >

Hazardous Weather Conditions

Current conditions at

The Florida Keys - Marathon International Airport (KMTH)

Lat: 24.73°NLon: 81.05°WElev: 13ft.

A Few Clouds

79°F

26°C

Humidity 82%
Wind Speed SE 8 mph
Barometer 30.02 in (1016.6 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 15 Mar 12:53 am EDT
Extended Forecast for

Key Colony Beach FL

  • Overnight

    Overnight: A chance of showers and thunderstorms. Mostly cloudy, with a low around 77. Southeast wind around 10 mph. Chance of precipitation is 40%.

    Low: 77 °F

    Chance
    T-storms

  • Sunday

    Sunday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 80. Southeast wind 10 to 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. Southeast wind 10 to 15 mph. Chance of precipitation is 50%.

    Low: 75 °F

    Chance
    T-storms

  • Monday

    Monday: A chance of showers and thunderstorms. Mostly sunny, with a high near 81. South wind around 10 mph. Chance of precipitation is 50%.

    High: 81 °F

    Chance
    T-storms

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 68. Southwest wind around 10 mph. Chance of precipitation is 70%.

    Low: 68 °F

    Showers
    Likely

  • Tuesday

    Tuesday: A chance of showers and thunderstorms. Cloudy, with a high near 74. Chance of precipitation is 50%.

    High: 74 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms. Cloudy, with a low around 65. Chance of precipitation is 50%.

    Low: 65 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 73. Chance of precipitation is 60%.

    High: 73 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely. Cloudy, with a low around 67. Chance of precipitation is 60%.

    Low: 67 °F

    Showers
    Likely

Detailed Forecast

Overnight
A chance of showers and thunderstorms. Mostly cloudy, with a low around 77. Southeast wind around 10 mph. Chance of precipitation is 40%.
Sunday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 80. Southeast wind 10 to 15 mph. Chance of precipitation is 60%.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Southeast wind 10 to 15 mph. Chance of precipitation is 50%.
Monday
A chance of showers and thunderstorms. Mostly sunny, with a high near 81. South wind around 10 mph. Chance of precipitation is 50%.
Monday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 68. Southwest wind around 10 mph. Chance of precipitation is 70%.
Tuesday
A chance of showers and thunderstorms. Cloudy, with a high near 74. Chance of precipitation is 50%.
Tuesday Night
A chance of showers and thunderstorms. Cloudy, with a low around 65. Chance of precipitation is 50%.
Wednesday
Showers likely and possibly a thunderstorm. Cloudy, with a high near 73. Chance of precipitation is 60%.
Wednesday Night
Showers likely. Cloudy, with a low around 67. Chance of precipitation is 60%.
Thursday
A chance of showers. Mostly cloudy, with a high near 75. Chance of precipitation is 40%.
Thursday Night
A chance of showers. Partly cloudy, with a low around 66. Chance of precipitation is 30%.
Friday
A slight chance of showers. Sunny, with a high near 74. Chance of precipitation is 10%.
Friday Night
A slight chance of showers. Partly cloudy, with a low around 67. Chance of precipitation is 10%.
Saturday
Sunny, with a high near 74.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Key Colony Beach FL
 24.74°N 81.02°W (Elev. 0 ft)
Last Update:
1:15 am EDT Mar 15, 2026
Forecast Valid:
1am EDT Mar 15, 2026-6pm EDT Mar 21, 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