Fallon, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Fallon, a community in Prairie County, Montana.
Overnight
43°F
Mostly Clear
Mostly clear, with a low around 43. West southwest wind around 5 mph.
7-day forecast for Fallon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 43°F | Mostly Clear | 5 mph WSW | 0% |
| Tuesday | 74°F | Sunny | 5 to 12 mph W | 0% |
| Tuesday Night | 48°F | Partly Cloudy | 1 to 9 mph WSW | 1% |
| Wednesday | 84°F | Mostly Sunny | 3 to 8 mph WSW | 0% |
| Wednesday Night | 53°F | Partly Cloudy | 2 to 7 mph SSW | 0% |
| Thursday | 91°F | Sunny | 2 to 6 mph W | 0% |
| Thursday Night | 57°F | Mostly Clear | 7 mph N | 0% |
| Friday | 93°F | Sunny | 3 to 7 mph E | 0% |
| Friday Night | 59°F | Mostly Clear | 3 to 8 mph NNE | 0% |
| Saturday | 94°F | Sunny | 3 to 10 mph NNE | 0% |
| Saturday Night | 60°F | Mostly Clear | 6 to 10 mph NNE | 2% |
| Sunday | 91°F | Mostly Sunny | 6 to 12 mph ENE | 4% |
| Sunday Night | 61°F | Partly Cloudy then Slight Chance Rain Showers | 8 to 12 mph NE | 20% |
| Monday | 89°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 8 to 13 mph ENE | 16% |
Forecast source: National Weather Service (api.weather.gov) for Fallon (46.837, -105.127). Updated through the day.
Growing snapshot for Fallon
Last spring frost
May 20
First fall frost
Sep 22
Growing season
124 days
Hardiness zone
4a
More local growing data for Fallon: nearby ZIP 59326 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mildred 5 N, Mt (4.9 mi from Fallon). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.