Jefferson City, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jefferson City, a community in Jefferson County, Montana.
Today
57°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy, with a high near 57. North northeast wind 5 to 8 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Jefferson City
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 57°F | Showers And Thunderstorms | 5 to 8 mph NNE | 95% |
| Tonight | 45°F | Chance Light Rain then Mostly Cloudy | 3 mph W | 9% |
| Sunday | 68°F | Mostly Sunny | 3 mph W | 2% |
| Sunday Night | 46°F | Mostly Clear | 2 to 6 mph S | 0% |
| Monday | 73°F | Sunny | 2 to 7 mph SW | 0% |
| Monday Night | 48°F | Mostly Clear | 2 to 6 mph WNW | 0% |
| Tuesday | 74°F | Sunny | 5 mph SSW | 0% |
| Tuesday Night | 49°F | Partly Cloudy | 3 mph WSW | 1% |
| Wednesday | 75°F | Sunny | 7 mph S | 2% |
| Wednesday Night | 50°F | Mostly Clear | 3 to 8 mph S | 3% |
| Thursday | 76°F | Sunny | 8 mph S | 2% |
| Thursday Night | 50°F | Mostly Clear | 5 to 9 mph S | 4% |
| Friday | 75°F | Mostly Sunny | 9 mph SSW | 6% |
| Friday Night | 47°F | Mostly Cloudy | 9 mph WSW | 14% |
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 Sep 19, 2026.