Jefferson City, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jefferson City, a community in Jefferson County, Montana.
Tonight
30°F
Mostly Cloudy
Mostly cloudy, with a low around 30. Southwest wind around 5 mph.
7-day forecast for Jefferson City
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 30°F | Mostly Cloudy | 5 mph SW | 0% |
| Wednesday | 48°F | Mostly Sunny | 2 mph NNW | 0% |
| Wednesday Night | 29°F | Mostly Clear | 1 to 9 mph SSW | 0% |
| Thursday | 48°F | Mostly Sunny | 1 to 10 mph WSW | 6% |
| Thursday Night | 30°F | Partly Cloudy | 1 to 13 mph WSW | 6% |
| Friday | 49°F | Mostly Sunny | 6 to 16 mph SW | 7% |
| Friday Night | 33°F | Partly Cloudy | 6 to 15 mph SW | 7% |
| Saturday | 51°F | Mostly Sunny | 3 to 14 mph SW | 0% |
| Saturday Night | 36°F | Partly Cloudy | 3 to 20 mph SSW | 0% |
| Sunday | 57°F | Mostly Sunny | 7 to 22 mph SSW | 1% |
| Sunday Night | 36°F | Mostly Cloudy | 7 to 12 mph SW | 1% |
| Monday | 53°F | Partly Sunny | 3 to 9 mph SSW | 2% |
| Monday Night | 36°F | Mostly Cloudy | 3 to 15 mph SSW | 2% |
| Tuesday | 55°F | Mostly Sunny | 6 to 17 mph SSW | 2% |
Forecast source: National Weather Service (api.weather.gov) for Jefferson City (46.378, -112.030). Updated through the day.
Growing snapshot for Jefferson City
Last spring frost
Jun 18
First fall frost
Sep 5
Growing season
81 days
Hardiness zone
4b
More local growing data for Jefferson City: nearby ZIP 59638 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Tizer Gardens, Mt (1.1 mi from Jefferson City). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.