Jefferson City, MT Weather & Growing Conditions
This Afternoon
45°F
Mostly Sunny
Mostly sunny. High near 45, with temperatures falling to around 38 in the afternoon. South wind around 3 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 45°F | Mostly Sunny | 3 mph S | 0% |
| Tonight | 29°F | Mostly Cloudy | 2 to 6 mph S | 0% |
| Wednesday | 45°F | Mostly Sunny | 3 mph N | 0% |
| Wednesday Night | 29°F | Mostly Clear | 1 to 10 mph SSW | 0% |
| Thursday | 45°F | Mostly Sunny | 2 to 10 mph SW | 6% |
| Thursday Night | 30°F | Partly Cloudy | 2 to 14 mph WSW | 6% |
| Friday | 45°F | Mostly Sunny | 6 to 15 mph SW | 7% |
| Friday Night | 33°F | Partly Cloudy | 6 to 16 mph SW | 7% |
| Saturday | 48°F | Mostly Sunny | 3 to 14 mph SW | 0% |
| Saturday Night | 35°F | Partly Cloudy | 3 to 18 mph SSW | 0% |
| Sunday | 54°F | Mostly Sunny | 7 to 20 mph SSW | 1% |
| Sunday Night | 35°F | Mostly Cloudy | 7 to 12 mph SW | 1% |
| Monday | 50°F | Partly Sunny | 3 to 9 mph SSW | 2% |
| Monday Night | 36°F | Mostly Cloudy | 3 to 15 mph SSW | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Jefferson City, MT
Last spring frost
Jun 18
First fall frost
Sep 5
Growing season
81 days
Hardiness zone
4b
Explore more for Jefferson City, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Tizer Gardens, Mt (1.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.