Weather forecast for 10 daysLewistown, MT

Weather forecast for the weekend

Sunday Oct 18, 2026

  • 59°F
  • 39°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 14mphE 98°
  • Humidity: 36%
  • UV index: 3
  • Sunrise: 7:40 am MDT
  • Sunset: 6:25 pm MDT
  • ▼
On Sunday, October 18, patchy clouds will move across the sky, allowing for sunshine at times.
Temperatures will oscillate between a mild 59°F at their highest and a wintry 39.2°F at their lowest.
Today's peak is predicted to be slightly warmer than the regular high for October at 52.2°F.
Sunrise was at 7:40 am and sunset will be at 6:25 pm; the daylight will last for 10h and 44min.

10-day overview

Daily temperatures

Warmest day: Thursday 72°C.
Coldest day: Tuesday 27.10. 41°C.

Chance of precipitation

Highest chance: Friday 80%.

Long-term weather forecast

  • Sunday
  • Oct 18, 2026
  • 59°F
  • 39°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 14mphE 98°
  • Humidity: 36%
  • UV index: 3
  • Sunrise: 7:40 am MDT
  • Sunset: 6:25 pm MDT
  • ▼
  • Monday
  • Oct 19, 2026
  • 70°F
  • 39°F
Sunny
Sunny
  • Precip. probability: 1%
  • Precipitation: 0"
  • Wind: 12mphSSW 212°
  • Humidity: 39%
  • UV index: 3
  • Sunrise: 7:42 am MDT
  • Sunset: 6:23 pm MDT
  • ▼
  • Tuesday
  • Oct 20, 2026
  • 59°F
  • 39°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 2%
  • Precipitation: 0"
  • Wind: 9mphWNW 284°
  • Humidity: 51%
  • UV index: 2
  • Sunrise: 7:43 am MDT
  • Sunset: 6:21 pm MDT
  • ▼
  • Wednesday
  • Oct 21, 2026
  • 68°F
  • 46°F
Sunny
Sunny
  • Precip. probability: 4%
  • Precipitation: 0"
  • Wind: 11mphSSW 200°
  • Humidity: 49%
  • UV index: 3
  • Sunrise: 7:44 am MDT
  • Sunset: 6:19 pm MDT
  • ▼
  • Thursday
  • Oct 22, 2026
  • 72°F
  • 46°F
Mostly Sunny
Mostly Sunny
  • Precip. probability: 2%
  • Precipitation: 0"
  • Wind: 10mphSW 215°
  • Humidity: 44%
  • UV index: 3
  • Sunrise: 7:46 am MDT
  • Sunset: 6:17 pm MDT
  • ▼
  • Friday
  • Oct 23, 2026
  • 50°F
  • 30°F
Rain
Rain
  • Precip. probability: 80%
  • Precipitation: 0.35"
  • Wind: 18mphWNW 286°
  • Humidity: 80%
  • UV index: 1
  • Sunrise: 7:47 am MDT
  • Sunset: 6:16 pm MDT
  • ▼
  • Saturday
  • Oct 24, 2026
  • 46°F
  • 32°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 8%
  • Precipitation: 0"
  • Wind: 12mphWSW 253°
  • Humidity: 57%
  • UV index: 2
  • Sunrise: 7:49 am MDT
  • Sunset: 6:14 pm MDT
  • ▼
  • Sunday
  • Oct 25, 2026
  • 50°F
  • 30°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 10mphSSW 203°
  • Humidity: 60%
  • UV index: 2
  • Sunrise: 7:50 am MDT
  • Sunset: 6:12 pm MDT
  • ▼
  • Monday
  • Oct 26, 2026
  • 45°F
  • 28°F
Mostly Cloudy
Mostly Cloudy
  • Precip. probability: 24%
  • Precipitation: 0"
  • Wind: 9mphWNW 292°
  • Humidity: 67%
  • UV index: 2
  • Sunrise: 7:52 am MDT
  • Sunset: 6:11 pm MDT
  • ▼
  • Tuesday
  • Oct 27, 2026
  • 41°F
  • 28°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 24%
  • Precipitation: 0"
  • Wind: 10mphW 278°
  • Humidity: 75%
  • UV index: 2
  • Sunrise: 7:53 am MDT
  • Sunset: 6:09 pm MDT
  • ▼
For the next ten days, a combination of dull, sunny and showery weather is forecasted.
With a probability of 80%, rainfall is predicted only for Friday. Expected precipitation will be light at 0.35".
The temperature will vary considerably throughout the forecast window. The temperature is expected to swing from 41°F up to 71.6°F, while the variation in nighttime lows will be also notably wide, as the lowest temperatures will be recorded between 28.4°F and 46.4°F.
Thursday is expected to be the warmest, reaching up to 71.6°F; the lowest daytime temperature of the period will be reached on next Tuesday, peaking at 41°F.
Updated: Oct 18, 2026 @ 16:27:14 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate

Frequently asked questions

On Sunday, moments of sunshine will break through the patchy clouds.

Today, the highest temperature will be 59°F, while the lowest temperature will be 39.2°F.
Today, the highest temperature will be moderately higher than the average maximum temperature in October. Today, the lowest temperature will be also slightly warmer than the average low temperature.

On Sunday, in Lewistown, sunrise was at 7:40 am and sunset will be at 6:25 pm (MDT).

Today, the daylight will last for 10h and 44min.