Big Arm, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Big Arm, a community in Lake County, Montana.
Overnight
51°F
Patchy Smoke
Patchy smoke before 5am. Mostly clear, with a low around 51. North northwest wind around 1 mph.
7-day forecast for Big Arm
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 51°F | Patchy Smoke | 1 mph NNW | 0% |
| Tuesday | 76°F | Sunny | 0 to 5 mph NE | 0% |
| Tuesday Night | 55°F | Mostly Clear | 0 to 3 mph NE | 0% |
| Wednesday | 83°F | Sunny | 0 to 5 mph ESE | 0% |
| Wednesday Night | 58°F | Mostly Clear | 0 to 5 mph W | 0% |
| Thursday | 88°F | Sunny | 0 to 5 mph E | 0% |
| Thursday Night | 61°F | Clear | 0 to 5 mph W | 0% |
| Friday | 91°F | Sunny | 0 to 8 mph WSW | 0% |
| Friday Night | 61°F | Clear | 2 to 13 mph SW | 0% |
| Saturday | 88°F | Sunny | 1 to 10 mph SW | 0% |
| Saturday Night | 60°F | Mostly Clear | 1 to 9 mph W | 0% |
| Sunday | 85°F | Sunny | 0 to 5 mph SW | 0% |
| Sunday Night | 59°F | Mostly Clear | 0 to 5 mph NNW | 0% |
| Monday | 83°F | Sunny | 0 to 3 mph ENE | 0% |
Forecast source: National Weather Service (api.weather.gov) for Big Arm (47.794, -114.270). Updated through the day.
Growing snapshot for Big Arm
Last spring frost
May 15
First fall frost
Sep 28
Growing season
134 days
Hardiness zone
6a
More local growing data for Big Arm: nearby ZIP 59910 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Bear Dance
Charlo
Dayton
Elmo
Finley Point
Jette
Kerr
Kicking Horse
Kings Point
Lake Mary Ronan
Lindisfarne
Niarada
Pablo
Polson
Ravalli
Rocky Point
Rollins
Ronan
St. Ignatius
Swan Lake
Turtle Lake
Climate data from the nearest NOAA station, Skq Dam, Mt (9.9 mi from Big Arm). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.