When to plant in Missoula, MT
USDA Zone 5bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Missoula, Montana — all computed from Missoula's nearest NOAA weather station.
In zone 5b, Missoula gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
The average last spring frost in Missoula is now 7 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
MISSOULA 2 NE · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Missoula’s own odds, recorded at MISSOULA 2 NE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 24 | Jun 1 | May 12 | Sep 3 | Sep 19 | Oct 2 |
| 32°F | May 28 | May 10 | Apr 27 | Sep 16 | Oct 1 | Oct 15 |
| 28°F | May 11 | Apr 28 | Apr 12 | Sep 28 | Oct 12 | Oct 25 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Missoula, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 7 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Missoula planting FAQ
When is the last spring frost in Missoula, MT?
On average, the last spring frost in Missoula is around May 10 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Missoula, MT?
In Missoula, the first 32°F freeze of fall lands around October 1 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Missoula in?
Missoula is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Missoula?
Missoula has about 144 frost-free days — a short growing season — between the average last spring frost (May 10) and first fall frost (October 1).
When should I plant tomatoes in Missoula?
For Missoula, sow tomatoes indoors about March 15–March 29 and move the seedlings out around May 17, after the last spring frost.
Never miss a window in Missoula
An email when it’s time to start seeds, transplant, and sow — timed to Missoula’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Kalispell · 151 km
- Butte-Silver Bow · 151 km
- Helena · 156 km
- Great Falls · 218 km
- Moscow · 227 km
- Coeur d'Alene · 228 km
- Hayden · 232 km
- Lewiston · 233 km
Frost dates recorded at MISSOULA 2 NE, 5 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Missoula, MT — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00245735. Retrieved from https://blissgarden.com/montana/missoula.