National Weather Service Forecast for: Great Falls MT
Issued by: National Weather Service Great Falls, MT
Updated: 12:31 am MDT Aug 20, 2026
 
Overnight

Overnight: Mostly clear, with a low around 56. South wind around 6 mph.
Mostly Clear


 Thursday

Thursday: Patchy smoke before 2pm. Sunny, with a high near 93. Southwest wind 5 to 9 mph becoming northwest in the afternoon. Winds could gust as high as 20 mph.
Patchy Smoke


 Thursday
Night
Thursday Night: Patchy smoke between 11pm and 4am. Mostly clear, with a low around 57. North northwest wind 5 to 8 mph becoming southeast after midnight.
Patchy Smoke


 Friday

Friday: Mostly sunny, with a high near 89. West wind 5 to 7 mph becoming calm.
Mostly Sunny


 Friday
Night
Friday Night: Partly cloudy, with a low around 59. East northeast wind 5 to 9 mph becoming calm after midnight.
Partly Cloudy


 Saturday

Saturday: Partly sunny, with a high near 92. Calm wind becoming east southeast around 6 mph in the afternoon.
Partly Sunny


 Saturday
Night
Saturday Night: A slight chance of showers and thunderstorms before 9pm, then a slight chance of showers between 9pm and midnight. Mostly cloudy, with a low around 60. South southwest wind around 8 mph. Chance of precipitation is 20%.
Slight Chance
T-storms then
Mostly Cloudy

 Sunday

Sunday: A slight chance of showers and thunderstorms after noon. Mostly sunny, with a high near 90. Breezy, with a south southwest wind 7 to 12 mph increasing to 18 to 23 mph in the afternoon. Winds could gust as high as 33 mph.
Mostly Sunny
then Slight
Chance
T-storms and
Breezy
 Sunday
Night
Sunday Night: Mostly clear, with a low around 55.
Mostly Clear
Lo 56 °F Hi 93 °F Lo 57 °F Hi 89 °F Lo 59 °F Hi 92 °F Lo 60 °F Hi 90 °F Lo 55 °F

 

Overnight
 
 Mostly clear, with a low around 56. South wind around 6 mph.
Thursday
 
 Patchy smoke before 2pm. Sunny, with a high near 93. Southwest wind 5 to 9 mph becoming northwest in the afternoon. Winds could gust as high as 20 mph.
Thursday Night
 
 Patchy smoke between 11pm and 4am. Mostly clear, with a low around 57. North northwest wind 5 to 8 mph becoming southeast after midnight.
Friday
 
 Mostly sunny, with a high near 89. West wind 5 to 7 mph becoming calm.
Friday Night
 
 Partly cloudy, with a low around 59. East northeast wind 5 to 9 mph becoming calm after midnight.
Saturday
 
 Partly sunny, with a high near 92. Calm wind becoming east southeast around 6 mph in the afternoon.
Saturday Night
 
 A slight chance of showers and thunderstorms before 9pm, then a slight chance of showers between 9pm and midnight. Mostly cloudy, with a low around 60. South southwest wind around 8 mph. Chance of precipitation is 20%.
Sunday
 
 A slight chance of showers and thunderstorms after noon. Mostly sunny, with a high near 90. Breezy, with a south southwest wind 7 to 12 mph increasing to 18 to 23 mph in the afternoon. Winds could gust as high as 33 mph.
Sunday Night
 
 Mostly clear, with a low around 55.
Monday
 
 Sunny, with a high near 84.
Monday Night
 
 Mostly clear, with a low around 54.
Tuesday
 
 Sunny, with a high near 86.
Tuesday Night
 
 Partly cloudy, with a low around 56.
Wednesday
 
 Mostly sunny, with a high near 88.

 

Forecast from NOAA-NWS for Great Falls MT.