National Weather Service Forecast for: Lewistown MT
Issued by: National Weather Service Great Falls, MT
Updated: 10:07 pm MST Dec 22, 2025
 
Tonight

Tonight: Mostly cloudy, with a low around 25. East southeast wind around 6 mph.
Mostly Cloudy

Tuesday

Tuesday: A slight chance of rain between 11am and 2pm.  Mostly cloudy, with a high near 46. South southeast wind 3 to 6 mph.  Chance of precipitation is 20%.
Slight Chance
Rain

Tuesday
Night
Tuesday Night: Mostly cloudy, with a steady temperature around 37. Southeast wind around 7 mph.
Mostly Cloudy

Wednesday

Wednesday: Partly sunny, with a high near 52. South southeast wind 7 to 10 mph, with gusts as high as 18 mph.
Partly Sunny

Wednesday
Night
Wednesday Night: A chance of rain after 11pm, mixing with snow after 2am.  Mostly cloudy, with a low around 28. South wind 5 to 8 mph becoming west after midnight.  Chance of precipitation is 40%. New snow accumulation of less than a half inch possible.
Chance Rain
then Chance
Rain/Snow
Christmas
Day
Christmas Day: A slight chance of rain and snow before 11am.  Mostly cloudy, with a high near 47. Southwest wind 3 to 7 mph.  Chance of precipitation is 20%.
Slight Chance
Rain/Snow
then Partly
Sunny
Thursday
Night
Thursday Night: A 10 percent chance of rain after 5am.  Mostly cloudy, with a low around 31. South wind around 7 mph.
Partly Cloudy
then Slight
Chance Rain
Friday

Friday: A slight chance of rain and snow before 11am, then a slight chance of rain after 5pm.  Partly sunny, with a high near 47. South southwest wind 7 to 16 mph, with gusts as high as 28 mph.
Slight Chance
Rain/Snow
then Slight
Chance Rain
Friday
Night
Friday Night: A slight chance of rain and snow before 8pm, then a slight chance of snow.  Mostly cloudy, with a low around 13.
Slight Chance
Rain/Snow
then Slight
Chance Snow
Lo 25 °F Hi 46 °F Lo 37 °F Hi 52 °F Lo 28 °F Hi 47 °F Lo 31 °F Hi 47 °F Lo 13 °F

 

Tonight
 
Mostly cloudy, with a low around 25. East southeast wind around 6 mph.
Tuesday
 
A slight chance of rain between 11am and 2pm. Mostly cloudy, with a high near 46. South southeast wind 3 to 6 mph. Chance of precipitation is 20%.
Tuesday Night
 
Mostly cloudy, with a steady temperature around 37. Southeast wind around 7 mph.
Wednesday
 
Partly sunny, with a high near 52. South southeast wind 7 to 10 mph, with gusts as high as 18 mph.
Wednesday Night
 
A chance of rain after 11pm, mixing with snow after 2am. Mostly cloudy, with a low around 28. South wind 5 to 8 mph becoming west after midnight. Chance of precipitation is 40%. New snow accumulation of less than a half inch possible.
Christmas Day
 
A slight chance of rain and snow before 11am. Mostly cloudy, with a high near 47. Southwest wind 3 to 7 mph. Chance of precipitation is 20%.
Thursday Night
 
A 10 percent chance of rain after 5am. Mostly cloudy, with a low around 31. South wind around 7 mph.
Friday
 
A slight chance of rain and snow before 11am, then a slight chance of rain after 5pm. Partly sunny, with a high near 47. South southwest wind 7 to 16 mph, with gusts as high as 28 mph.
Friday Night
 
A slight chance of rain and snow before 8pm, then a slight chance of snow. Mostly cloudy, with a low around 13.
Saturday
 
Partly sunny, with a high near 29.
Saturday Night
 
Partly cloudy, with a low around 16.
Sunday
 
Partly sunny, with a high near 44.
Sunday Night
 
Mostly clear, with a low around 28.
Monday
 
Mostly sunny, with a high near 52.

 

Forecast from NOAA-NWS for Lewistown MT.