Montana averages 6 tornadoes per year. Most occur in the eastern plains where Great Plains conditions extend into the state. Western Montana's mountain terrain essentially eliminates tornado formation. Population density is very low, so most tornadoes strike open country.
Eastern Montana extends the Great Plains north. Similar conditions to Wyoming and North Dakota.
Occasional Gulf moisture reaches during summer, triggering severe weather.
Rocky Mountains limit tornado activity to central and eastern Montana.
Billings, Miles City area. Great Plains extension. Highest tornado density.
Great Falls area. Moderate risk.
Missoula, Kalispell. Very rare tornadoes due to mountain terrain.