| NWS Forecast for: Lewistown MT Issued by: National Weather Service Great Falls, MT Last Update: 12:31 pm MDT Aug 18, 2026 |  |
| This Afternoon: A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 80. West northwest wind around 8 mph, with gusts as high as 18 mph. Tonight: A slight chance of showers and thunderstorms before 9pm, then a slight chance of showers between 9pm and midnight. Partly cloudy, with a low around 52. West wind 5 to 10 mph becoming south southeast in the evening. Chance of precipitation is 20%. Wednesday: Patchy smoke after 11am. Sunny, with a high near 83. South wind 5 to 9 mph becoming west northwest in the afternoon. Winds could gust as high as 20 mph. Wednesday Night: Patchy smoke before 9pm. Mostly clear, with a low around 53. Northwest wind 5 to 7 mph becoming calm after midnight. Thursday: Sunny, with a high near 86. Calm wind becoming north northwest around 6 mph in the afternoon. Thursday Night: Mostly clear, with a low around 53. North wind 5 to 7 mph becoming light and variable after midnight. Friday: Sunny, with a high near 86. Light southeast wind becoming east 5 to 10 mph in the afternoon. Winds could gust as high as 20 mph. Friday Night: Mostly cloudy, with a low around 57. East southeast wind 10 to 14 mph, with gusts as high as 20 mph. Saturday: A chance of showers, with thunderstorms also possible after noon. Partly sunny, with a high near 87. Saturday Night: A chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 56. Sunday: Mostly sunny, with a high near 83. Sunday Night: Mostly clear, with a low around 52. Monday: Sunny, with a high near 83. Monday Night: Partly cloudy, with a low around 54. Tuesday: Mostly sunny, with a high near 86. | |
| Lewistown MT 47.07°N 109.43°W (Elev. 3898 ft) | |
Visit your local NWS office at: https://www.weather.gov/tfx |
