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

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Hazardous Weather Conditions

Current conditions at

Lewistown, Lewistown Municipal Airport (KLWT)

Lat: 47.04917°NLon: 109.46639°WElev: 4167.0ft.

Clear

30°F

-1°C

Humidity 86%
Wind Speed ESE 3 MPH
Barometer 29.65 in (1004.06 mb)
Dewpoint 27°F (-3°C)
Visibility 10.00 mi
Last update 24 Dec 10:15 PM MST
Extended Forecast for

Lewistown Municipal MT

Dense Fog Advisory December 24, 10:30pm until December 24, 11:00pm
Click here for hazard details and duration
...
  •  
    Dense Fog Advisory December 24, 10:30pm until December 24, 11:00pm

    NOW until 11:00pm Wed

    Dense Fog Advisory

  • Tonight

    Low: 28 °F

    Mostly Cloudy

  • Christmas Day

    Christmas Day: Mostly sunny, with a high near 52. Southwest wind 6 to 9 mph, with gusts as high as 18 mph.

    High: 52 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 35. South southwest wind around 10 mph, with gusts as high as 21 mph.

    Low: 35 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 49. Southwest wind 10 to 16 mph, with gusts as high as 28 mph.

    High: 49 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 12. Southwest wind around 14 mph, with gusts as high as 24 mph.

    Low: 12 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 20. Northwest wind 13 to 17 mph, with gusts as high as 28 mph.

    High: 20 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around -1. West wind 7 to 15 mph, with gusts as high as 24 mph.

    Low: -1 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 31. West wind around 6 mph.

    High: 31 °F

    Sunny

Detailed Forecast

Tonight
Mostly cloudy, with a low around 28. Southeast wind 7 to 9 mph becoming west southwest after midnight.
Christmas Day
Mostly sunny, with a high near 52. Southwest wind 6 to 9 mph, with gusts as high as 18 mph.
Thursday Night
Partly cloudy, with a low around 35. South southwest wind around 10 mph, with gusts as high as 21 mph.
Friday
Mostly sunny, with a high near 49. Southwest wind 10 to 16 mph, with gusts as high as 28 mph.
Friday Night
Partly cloudy, with a low around 12. Southwest wind around 14 mph, with gusts as high as 24 mph.
Saturday
Partly sunny, with a high near 20. Northwest wind 13 to 17 mph, with gusts as high as 28 mph.
Saturday Night
Partly cloudy, with a low around -1. West wind 7 to 15 mph, with gusts as high as 24 mph.
Sunday
Sunny, with a high near 31. West wind around 6 mph.
Sunday Night
Partly cloudy, with a low around 17.
Monday
Mostly sunny, with a high near 45.
Monday Night
Partly cloudy, with a low around 28.
Tuesday
Partly sunny, with a high near 48.
Tuesday Night
Mostly cloudy, with a low around 28.
Wednesday
Mostly sunny, with a high near 48.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Lewistown Municipal MT
 47.04°N 109.45°W (Elev. 4111 ft)
Last Update:
9:43 pm MST Dec 24, 2025
Forecast Valid:
10pm MST Dec 24, 2025-6pm MST Dec 31, 2025
 
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Additional Resources

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