When is the last frost in Garrett, WY?

Frost is possible in any month at the nearest NOAA station (Shirley Basin, WY), so there is no reliable average last frost date.

When is the first frost in Garrett, WY?

Frost is possible in any month at the nearest NOAA station.

Are these frost dates a forecast?

No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.

Frost dates for 82058Garrett, WY

Frost is possible in any month near Garrett, based on NOAA 1991-2020 records for the Shirley Basin, WY station.

Frost is possible in any month. Even summer nights can drop to freezing at this station, so protect tender plants whenever cold nights are forecast.

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
Temperature	Last spring: 90% / 50% / 10% chance	First fall: 10% / 50% / 90% chance	Growing season (50%)	Years with at least one
Light frost (36°F)	—	—	46 days	100%
Frost / freeze (32°F)	—	—	75 days	100%
Hard freeze (28°F)	May 13 · May 30 · Jun 15	Aug 28 · Sep 12 · Sep 26	104 days	100%

Where these dates come from

ZIP code 82058 is matched to the NOAA station Shirley Basin, WY, 39.7 km away, at 7,057 ft elevation (381 ft lower than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Shirley Basin, WY (used)	7,057 ft	—	—
Double Four Rch, WY	6,120 ft	Jun 2	Sep 9
Sybille Rsch Unit, WY	6,086 ft	May 22	Sep 24
Medicine Bow, WY	6,635 ft	Jun 1	Sep 8

Frost dates near Garrett

Medicine Bow, WY 82329 · last Jun 1, first Sep 8
Rock River, WY 82083 · last Jun 1, first Sep 8
Wheatland, WY 82201 · last May 19, first Sep 22
Glendo, WY 82213 · last May 9, first Oct 5
Glenrock, WY 82637 · last May 10, first Sep 29
Douglas, WY 82633 · last May 19, first Sep 23
Bosler, WY 82051 · last Jun 7, first Sep 4
Guernsey, WY 82214 · last May 11, first Oct 3

Frequently asked questions

When is the last frost in Garrett, WY?: Frost is possible in any month at the nearest NOAA station (Shirley Basin, WY), so there is no reliable average last frost date.
When is the first frost in Garrett, WY?: Frost is possible in any month at the nearest NOAA station.
Are these frost dates a forecast?: No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.