Weather forecast for 10 daysBig Arm, MT
Weather forecast for the weekend
Sunday Oct 18, 2026
- 61°F
- 34°F
Partly Cloudy
- Precip. probability: 6%
- Precipitation: 0"
- Wind: 4mphNE 44°
- Humidity: 68%
- UV index: 3
- Sunrise: 8:01 am MDT
- Sunset: 6:43 pm MDT
- details ▼
Tomorrow, on Sunday, October 18, clouds will come and go, but expect bright periods in between.
Temperature changes will be remarkable, ranging from a high of an enjoyable 60.8°F to a low of a wintry 33.8°F.
The temperature of 60.8°F aligns more with what is typical in September than what is normal in October.
Sunrise will be at 8:01 am and sunset at 6:43 pm; tomorrow's daylight will last for 10h and 42min.
Temperature changes will be remarkable, ranging from a high of an enjoyable 60.8°F to a low of a wintry 33.8°F.
The temperature of 60.8°F aligns more with what is typical in September than what is normal in October.
Sunrise will be at 8:01 am and sunset at 6:43 pm; tomorrow's daylight will last for 10h and 42min.
10-day overview
Daily temperatures
Warmest period: Tuesday - Thursday 63°C.
Coldest day: Sunday 25.10. 45°C.
Coldest day: Sunday 25.10. 45°C.
Chance of precipitation
Highest chance: Friday 44%.
Long-term weather forecast
- Saturday
- Oct 17, 2026
- min.
- 36°F
Partly Cloudy
- Precip. probability: 3%
- Precipitation: 0"
- Wind: 5mphW 264°
- Humidity: 77%
- UV index: 0
- Sunrise: 7:59 am MDT
- Sunset: 6:45 pm MDT
- details ▼
- Sunday
- Oct 18, 2026
- 61°F
- 34°F
Partly Cloudy
- Precip. probability: 6%
- Precipitation: 0"
- Wind: 4mphNE 44°
- Humidity: 68%
- 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: 3%
- Precipitation: 0"
- Wind: 4mphNE 37°
- Humidity: 68%
- UV index: 2
- Sunrise: 8:02 am MDT
- Sunset: 6:41 pm MDT
- details ▼
- Tuesday
- Oct 20, 2026
- 63°F
- 36°F
Partly Cloudy
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 4mphNE 36°
- Humidity: 68%
- 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: 6%
- Precipitation: 0"
- Wind: 4mphE 81°
- Humidity: 65%
- UV index: 2
- Sunrise: 8:05 am MDT
- Sunset: 6:37 pm MDT
- details ▼
- Thursday
- Oct 22, 2026
- 63°F
- 41°F
PM Showers
- Precip. probability: 39%
- Precipitation: 0.24"
- Wind: 4mphS 171°
- Humidity: 68%
- 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: 44%
- Precipitation: 0.08"
- Wind: 9mphWSW 247°
- Humidity: 83%
- UV index: 2
- Sunrise: 8:08 am MDT
- Sunset: 6:34 pm MDT
- details ▼
- Saturday
- Oct 24, 2026
- 46°F
- 30°F
Partly Cloudy
- Precip. probability: 12%
- Precipitation: 0.04"
- Wind: 6mphSSW 208°
- Humidity: 71%
- UV index: 2
- Sunrise: 8:10 am MDT
- Sunset: 6:32 pm MDT
- details ▼
- Sunday
- Oct 25, 2026
- 45°F
- 28°F
AM Ice
- Precip. probability: 24%
- Precipitation: 0.04"
- Wind: 7mphNNE 28°
- Humidity: 75%
- UV index: 2
- Sunrise: 8:11 am MDT
- Sunset: 6:30 pm MDT
- details ▼
- Monday
- Oct 26, 2026
- 46°F
- 30°F
Mostly Sunny
- Precip. probability: 13%
- Precipitation: 0"
- Wind: 6mphNNE 20°
- Humidity: 73%
- UV index: 2
- Sunrise: 8:13 am MDT
- Sunset: 6:29 pm MDT
- details ▼
The weather will be unstable for the next ten days, and a mix of cloudy, rainy, mixed-precipitation and sunny weather is forecasted.
Rainfall is expected on Thursday through next Sunday.
Temperature differences will be noticeable in the next ten days. Forecast highs will fluctuate between 44.6°F and 62.6°F, while the lowest nightly temperature differences will be also quite pronounced, as the minimum temperature is expected to range between 28.4°F and 41°F.
Tuesday through Thursday, with the highest temperature of 62.6°F, will be the warmest days; the lowest daytime temperature of the period will be reached on next Sunday, peaking at 44.6°F.
Rainfall is expected on Thursday through next Sunday.
Temperature differences will be noticeable in the next ten days. Forecast highs will fluctuate between 44.6°F and 62.6°F, while the lowest nightly temperature differences will be also quite pronounced, as the minimum temperature is expected to range between 28.4°F and 41°F.
Tuesday through Thursday, with the highest temperature of 62.6°F, will be the warmest days; the lowest daytime temperature of the period will be reached on next Sunday, peaking at 44.6°F.
Updated: Oct 18, 2026 @ 05:26:45 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
Tomorrow, moments of sunshine will break through the patchy clouds.
Tomorrow, the highest temperature will be 60.8°F, while the lowest temperature will be 33.8°F.
Tomorrow, the maximum temperature will be noticeably higher than the average highest temperature of 51.1°F in October. Tomorrow, the lowest temperature will be in line with the average low temperature.
Tomorrow, the maximum temperature will be noticeably higher than the average highest temperature of 51.1°F in October. Tomorrow, the lowest temperature will be in line with the average low temperature.
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 tomorrow will be 10h and 42min.
