Harrison, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harrison, a community in Madison County, Montana.
This Afternoon
69°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely. Mostly cloudy. High near 69, with temperatures falling to around 66 in the afternoon. East northeast wind 3 to 7 mph. Chance of precipitation is 70%.
7-day forecast for Harrison
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Showers And Thunderstorms Likely | 3 to 7 mph ENE | 71% |
| Tonight | 50°F | Showers And Thunderstorms | 1 to 7 mph NW | 100% |
| Saturday | 57°F | Patchy Fog | 1 to 5 mph NNW | 94% |
| Saturday Night | 47°F | Light Rain Likely | 0 to 3 mph WNW | 58% |
| Sunday | 66°F | Areas Of Fog then Partly Sunny | 1 mph NNE | 11% |
| Sunday Night | 46°F | Mostly Clear | 1 mph E | 0% |
| Monday | 73°F | Sunny | 2 mph N | 0% |
| Monday Night | 48°F | Mostly Clear | 1 mph S | 1% |
| Tuesday | 74°F | Mostly Sunny | 1 mph N | 1% |
| Tuesday Night | 49°F | Partly Cloudy | 2 mph SW | 3% |
| Wednesday | 75°F | Sunny | 1 mph WSW | 2% |
| Wednesday Night | 49°F | Mostly Clear | 0 to 3 mph SSW | 1% |
| Thursday | 76°F | Sunny | 1 mph WNW | 2% |
| Thursday Night | 50°F | Mostly Clear | 0 to 6 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Harrison (45.704, -111.784). Updated through the day.
Growing snapshot for Harrison
Last spring frost
Apr 30
First fall frost
Oct 10
Growing season
162 days
Hardiness zone
5a
More local growing data for Harrison: nearby ZIP 59735 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Alder
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Sheridan
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Twin Bridges
Virginia City
Climate data from the nearest NOAA station, Norris Madison Pwr House, Mt (15.3 mi from Harrison). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.