Fall First Freeze Statistics

Wondering how long the growing season lasts in your area?

Here are statistics for select climate sites in southeast Wyoming and western Nebraska with long records, based on data from 1951-2025.

We have included the historical probability of a freeze by specific dates. A 50% chance (the median) means half of all years in the record had a freeze before this date, and half after. A 90% chance means in 90% of years, the first freeze occurred on or before this date.

Wyoming Locations

Cheyenne, WY

Average First Fall Freeze: September 30
Last Year's First Freeze: October 13, 2025
Earliest First Freeze: September 7, 2020
Latest First Freeze: October 27, 1963

	36°F	32°F	28°F
10% chance by	Sep 7	Sep 13	Sep 21
50% chance by	Sep 20	Sep 29	Oct 9
90% chance by	Oct 2	Oct 15	Oct 27

Laramie, WY

Average First Fall Freeze: September 13
Last Year's First Freeze: October 7, 2025
Earliest First Freeze: August 18, 1960
Latest First Freeze: October 19, 2024

	36°F	32°F	28°F
10% chance by	Aug 15	Aug 31	Sep 10
50% chance by	Sep 2	Sep 13	Sep 21
90% chance by	Sep 15	Sep 23	Oct 6

Rawlins, WY

Average First Fall Freeze: September 16
Last Year's First Freeze: September 18, 2025
Earliest First Freeze: August 17, 2009
Latest First Freeze: October 8, 1963

	36°F	32°F	28°F
10% chance by	Aug 23	Sep 3	Sep 12
50% chance by	Sep 7	Sep 16	Sep 25
90% chance by	Sep 19	Sep 25	Oct 12

Nebraska Locations

Alliance, NE

Average First Fall Freeze: September 23
Last Year's First Freeze: September 6, 2025
Earliest First Freeze: September 2, 2006
Latest First Freeze: October 17, 1963

	36°F	32°F	28°F
10% chance by	Sep 2	Sep 9	Sep 20
50% chance by	Sep 16	Sep 22	Oct 5
90% chance by	Sep 26	Oct 5	Oct 16

Scottsbluff, NE

Average First Fall Freeze: September 30
Last Year's First Freeze: October 18, 2025
Earliest First Freeze: September 3, 1974
Latest First Freeze: October 27, 1963

	36°F	32°F	28°F
10% chance by	Sep 8	Sep 17	Sep 25
50% chance by	Sep 20	Sep 30	Oct 9
90% chance by	Oct 4	Oct 13	Oct 23

Chadron, NE

Average First Fall Freeze: September 26
Last Year's First Freeze: September 6, 2025
Earliest First Freeze: September 6, 2017 & 2025
Latest First Freeze: October 26, 1963

	36°F	32°F	28°F
10% chance by	Sep 2	Sep 13	Sep 19
50% chance by	Sep 16	Sep 24	Oct 5
90% chance by	Sep 29	Oct 10	Oct 24

Sidney, NE

Average First Fall Freeze: September 27
Last Year's First Freeze: October 7, 2025
Earliest First Freeze: September 2, 2006
Latest First Freeze: October 28, 1963

	36°F	32°F	28°F
10% chance by	Sep 4	Sep 12	Sep 21
50% chance by	Sep 18	Sep 26	Oct 5
90% chance by	Sep 30	Oct 8	Oct 23