Fallon, MT Weather & Growing Conditions
Overnight
45°F
Mostly Clear
Mostly clear, with a low around 45. West southwest wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 45°F | Mostly Clear | 5 mph WSW | 0% |
| Tuesday | 73°F | Sunny | 5 to 12 mph W | 0% |
| Tuesday Night | 49°F | Partly Cloudy | 2 to 9 mph SW | 1% |
| Wednesday | 83°F | Mostly Sunny | 3 to 9 mph WSW | 0% |
| Wednesday Night | 54°F | Partly Cloudy | 2 to 7 mph S | 0% |
| Thursday | 90°F | Sunny | 2 to 6 mph W | 0% |
| Thursday Night | 57°F | Mostly Clear | 7 mph N | 0% |
| Friday | 92°F | Sunny | 3 to 8 mph ESE | 0% |
| Friday Night | 60°F | Mostly Clear | 6 to 9 mph NE | 1% |
| Saturday | 93°F | Sunny | 5 to 9 mph NNE | 0% |
| Saturday Night | 61°F | Mostly Clear | 6 to 10 mph NNE | 2% |
| Sunday | 92°F | Mostly Sunny | 6 to 12 mph ENE | 5% |
| Sunday Night | 62°F | Partly Cloudy then Slight Chance Rain Showers | 8 to 12 mph ENE | 21% |
| Monday | 88°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 7 to 13 mph ENE | 17% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Fallon, MT
Last spring frost
May 20
First fall frost
Sep 22
Growing season
124 days
Hardiness zone
4a
Explore more for Fallon, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Mildred 5 N, Mt (4.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.