Weather forecast for 10 daysBig Arm, MT
Weather forecast for the weekend
Sunday Oct 18, 2026
- 61°F
- 34°F
Sunny
- Precip. probability: 2%
- Precipitation: 0"
- Wind: 4mphNE 43°
- Humidity: 66%
- UV index: 3
- Sunrise: 8:01 am MDT
- Sunset: 6:43 pm MDT
- details ▼
On Sunday, October 18, clear and sunny conditions are expected.
The day's temperature range will span from a high of a comfortable 60.8°F to a minimum of an icy 33.8°F.
Expect temperatures to match September's average maximum of 67.6°F rather than October's 51.1°F.
Sunrise will be at 8:01 am and sunset at 6:43 pm; the daylight will last for 10h and 42min.
The day's temperature range will span from a high of a comfortable 60.8°F to a minimum of an icy 33.8°F.
Expect temperatures to match September's average maximum of 67.6°F rather than October's 51.1°F.
Sunrise will be at 8:01 am and sunset at 6:43 pm; the daylight will last for 10h and 42min.
10-day overview
Daily temperatures
Warmest period: Tuesday - Thursday 63°C.
Coldest period: Monday - Tuesday 43°C.
Coldest period: Monday - Tuesday 43°C.
Chance of precipitation
Highest chance: Friday 45%.
Long-term weather forecast
- Sunday
- Oct 18, 2026
- 61°F
- 34°F
Sunny
- Precip. probability: 2%
- Precipitation: 0"
- Wind: 4mphNE 43°
- Humidity: 66%
- UV index: 3
- Sunrise: 8:01 am MDT
- Sunset: 6:43 pm MDT
- details ▼
- Monday
- Oct 19, 2026
- 61°F
- 36°F
Partly Cloudy
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 3mphNE 36°
- Humidity: 68%
- UV index: 3
- Sunrise: 8:02 am MDT
- Sunset: 6:41 pm MDT
- details ▼
- Tuesday
- Oct 20, 2026
- 63°F
- 37°F
Partly Cloudy
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 4mphNE 43°
- Humidity: 70%
- UV index: 2
- Sunrise: 8:04 am MDT
- Sunset: 6:39 pm MDT
- details ▼
- Wednesday
- Oct 21, 2026
- 63°F
- 39°F
Partly Cloudy
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 4mphENE 68°
- Humidity: 66%
- UV index: 2
- Sunrise: 8:05 am MDT
- Sunset: 6:37 pm MDT
- details ▼
- Thursday
- Oct 22, 2026
- 63°F
- 41°F
Mostly Cloudy
- Precip. probability: 24%
- Precipitation: 0.2"
- Wind: 4mphE 94°
- Humidity: 69%
- UV index: 2
- Sunrise: 8:07 am MDT
- Sunset: 6:36 pm MDT
- details ▼
- Friday
- Oct 23, 2026
- 50°F
- 30°F
AM Showers
- Precip. probability: 45%
- Precipitation: 0.04"
- Wind: 9mphWSW 241°
- Humidity: 83%
- UV index: 2
- Sunrise: 8:08 am MDT
- Sunset: 6:34 pm MDT
- details ▼
- Saturday
- Oct 24, 2026
- 48°F
- 30°F
Partly Cloudy
- Precip. probability: 9%
- Precipitation: 0"
- Wind: 6mphSSW 211°
- Humidity: 73%
- UV index: 2
- Sunrise: 8:10 am MDT
- Sunset: 6:32 pm MDT
- details ▼
- Sunday
- Oct 25, 2026
- 45°F
- 28°F
AM Snow Showers
- Precip. probability: 30%
- Precipitation: 0.04"
- Wind: 9mphNNE 23°
- Humidity: 80%
- UV index: 2
- Sunrise: 8:11 am MDT
- Sunset: 6:30 pm MDT
- details ▼
- Monday
- Oct 26, 2026
- 43°F
- 28°F
Partly Cloudy
- Precip. probability: 24%
- Precipitation: 0"
- Wind: 6mphNNE 14°
- Humidity: 79%
- UV index: 2
- Sunrise: 8:13 am MDT
- Sunset: 6:29 pm MDT
- details ▼
- Tuesday
- Oct 27, 2026
- 43°F
- 28°F
Partly Cloudy
- Precip. probability: 24%
- Precipitation: 0"
- Wind: 7mphNW 323°
- Humidity: 85%
- UV index: 2
- Sunrise: 8:14 am MDT
- Sunset: 6:27 pm MDT
- details ▼
Mixed conditions are forecasted for the coming ten days, and a combination of primarily dull and occasionally sunny, rainy and snowy weather is anticipated.
Rain is forecasted for Thursday and Friday.
With a 30% probability, snowfall is forecasted only for next Sunday. The precipitation will be moderate at 0.2".
Temperature variation will be noticeable throughout the forecast window. Highs will range from 42.8°F to 62.6°F, while the lowest night temperatures will vary also significantly, as the overnight lows will vary from 28.4°F to 41°F.
The warmest days in Big Arm will be Tuesday through Thursday, with a maximum of 62.6°F; with a maximum temperature of 42.8°F, next Monday and Tuesday will be the coldest days in Big Arm.
Rain is forecasted for Thursday and Friday.
With a 30% probability, snowfall is forecasted only for next Sunday. The precipitation will be moderate at 0.2".
Temperature variation will be noticeable throughout the forecast window. Highs will range from 42.8°F to 62.6°F, while the lowest night temperatures will vary also significantly, as the overnight lows will vary from 28.4°F to 41°F.
The warmest days in Big Arm will be Tuesday through Thursday, with a maximum of 62.6°F; with a maximum temperature of 42.8°F, next Monday and Tuesday will be the coldest days in Big Arm.
Updated: Oct 18, 2026 @ 12:09:21 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Frequently asked questions
Today, bright and sunny weather is expected.
Today, the maximum temperature in Big Arm will be 60.8°F, while the minimum temperature will be 33.8°F.
The maximum temperature today will be uncommonly higher than the average highest temperature of 51.1°F in October. The lowest temperature will be in line with the average low of 33.1°F.
The maximum temperature today will be uncommonly higher than the average highest temperature of 51.1°F in October. The lowest temperature will be in line with the average low of 33.1°F.
On Sunday, in Big Arm, sunrise will be at 8:01 am and sunset at 6:43 pm (MDT).
In Big Arm, Montana, the length of the day today will be 10h and 42min.
