Weather forecast for tomorrowBig Arm, MT

Weather forecast for tomorrow

Monday Oct 19, 2026

  • 61°F
  • 36°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 4%
  • Precipitation: 0"
  • Wind: 3mphNE 35°
  • Humidity: 68%
  • UV index: 3
  • Sunrise: 8:02 am MDT
  • Sunset: 6:41 pm MDT
  • ▼
Tomorrow, on Monday, sunny moments will alternate with patchy cloud cover.
The temperature scale will run from a maximum of an enjoyable 60.8°F to a minimum of an icy 35.6°F.
The anticipated high is warmer and better reflects September's normal temperature profile than that of October.
Sunrise will be at 8:02 am and sunset at 6:41 pm; tomorrow's daylight will last for 10h and 39min.

Hourly overview

Hourly temperatures

Warmest period: 3 pm - 6 pm 57°C.
Coldest hour: 6 am 36°C.

Chance of precipitation

Highest chance: 9 am 4%.

Hourly weather forecast

  • 12 am
  • 41°F
  • Feels like:
    41°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 2%
  • Precipitation: 0"
  • Wind: 2mphNNW 344°
  • Humidity: 78%
  • Pressure: 30"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
  • 2 am
  • 39°F
  • Feels like:
    39°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 3%
  • Precipitation: 0"
  • Wind: 1mphNW 323°
  • Humidity: 82%
  • Pressure: 29.97"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
  • 4 am
  • 37°F
  • Feels like:
    37°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 3%
  • Precipitation: 0"
  • Wind: 1mphNNW 347°
  • Humidity: 85%
  • Pressure: 29.94"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
  • 6 am
  • 36°F
  • Feels like:
    36°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 3%
  • Precipitation: 0"
  • Wind: 1mphNW 323°
  • Humidity: 86%
  • Pressure: 29.94"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
  • 8 am
  • 36°F
  • Feels like:
    36°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 4%
  • Precipitation: 0"
  • Wind: 1mphNW 313°
  • Humidity: 89%
  • Pressure: 29.94"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
Sunrise: 8:02 am
  • 10 am
  • 41°F
  • Feels like:
    41°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 2%
  • Precipitation: 0"
  • Wind: 1mphNNE 14°
  • Humidity: 86%
  • Pressure: 29.94"Hg
  • Visibility: 10mi
  • UV index: 1
  • ▼
  • 12 pm
  • 48°F
  • Feels like:
    48°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 1mphNE 36°
  • Humidity: 69%
  • Pressure: 29.91"Hg
  • Visibility: 10mi
  • UV index: 2
  • ▼
  • 2 pm
  • 54°F
  • Feels like:
    54°F
Mostly Cloudy
Mostly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 2mphENE 71°
  • Humidity: 59%
  • Pressure: 29.85"Hg
  • Visibility: 10mi
  • UV index: 2
  • ▼
  • 4 pm
  • 59°F
  • Feels like:
    59°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 3mphENE 75°
  • Humidity: 49%
  • Pressure: 29.83"Hg
  • Visibility: 10mi
  • UV index: 1
  • ▼
  • 6 pm
  • 57°F
  • Feels like:
    57°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 3mphNE 43°
  • Humidity: 52%
  • Pressure: 29.85"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
Sunset: 6:41 pm
  • 8 pm
  • 50°F
  • Feels like:
    50°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 1%
  • Precipitation: 0"
  • Wind: 2mphN 356°
  • Humidity: 70%
  • Pressure: 29.85"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
  • 10 pm
  • 46°F
  • Feels like:
    46°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 2%
  • Precipitation: 0"
  • Wind: 1mphNNW 341°
  • Humidity: 79%
  • Pressure: 29.88"Hg
  • Visibility: 10mi
  • UV index: 0
  • ▼
Tomorrow, on Monday, primarily cloudy and occasionally sun-filled weather is forecasted.
The temperature will vary between the lowest temperature of 35.6°F and the highest temperature of 59°F. The warmest part of the day will be at 4 pm and 5 pm.
The day’s peak temperature will reflect September's norm of 67.6°F more than October's 51.1°F. The night temperature will be consistent with the standard October low of 33.1°F.
Updated: Oct 18, 2026 @ 09:44:52 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate

Frequently asked questions

Tomorrow, sunny moments will alternate with patchy cloud cover.

Tomorrow, the highest temperature will be 60.8°F, while the lowest temperature will be 35.6°F.
The highest temperature will be noticeably higher than the average maximum of 51.1°F in October. The lowest temperature will be in line with the average low of 33.1°F.

On Monday, in Big Arm, sunrise will be at 8:02 am and sunset at 6:41 pm (MDT).

In Big Arm, the length of the day tomorrow will be 10h and 39min.