National Drought Mitigation Center

Freeze Free Period

Freeze-free periods range from 60 to 90 days in North Dakota to 210 to 240 days in south-central Texas through the semiarid and sub-humid climate regions.

Most of the semiarid region in Montana, North Dakota, South Dakota, and Nebraska has a freeze-free period of 110 to 130 days.

Freeze free period map of Great Plains
Freeze free map legend

Freeze Free Period:  You have a 90% chance of having this many days or longer with temperatures above 32 degrees F.