Wyoming Frost Dates
Wyoming has 156 NOAA weather stations with freeze records in the 1991–2020 climate normals. The typical last spring frost ranges from April 28 at Basin to June 24 at Moose 1 Nne; at half the stations it has come by May 20. The first fall frost typically arrives between August 28 at Moose 1 Nne and October 10 at Basin, with a median of September 24.
The growing season between the typical frosts runs from 63 days at Moose 1 Nne to 164 days at Basin; 125 days at the median station.
At 28 stations, a freeze is possible in any month.
Every station in Wyoming
Typical dates have a 50% chance of a frost after them in spring, and before them in fall; safer dates, 10%. A garden can differ from its nearest station, especially in a valley or on a hillside: see why your garden may differ.
| Station | Elevation | Last frost | Safer | First frost | Safer | Season (days) |
|---|---|---|---|---|---|---|
| Afton | 6,248 ft | Jun 20 | Jul 7 | Sep 1 | Aug 12 | 71 |
| Albin | 5,345 ft | May 14 | May 25 | Oct 2 | Sep 18 | 142 |
| Alta 1 Nnw | 6,440 ft | Jun 14 | Jul 4 | Sep 11 | Aug 28 | 85 |
| Archer | 6,010 ft | May 21 | Jun 6 | Sep 24 | Sep 8 | 124 |
| Atlantic City | 7,821 ft | A freeze is possible in any month | ||||
| Baggs | 6,319 ft | Jun 1 | Jun 18 | Sep 18 | Sep 4 | 108 |
| Basin | 3,840 ft | Apr 28 | May 11 | Oct 10 | Sep 26 | 164 |
| Bates Creek #2 | 6,042 ft | May 22 | Jun 6 | Sep 26 | Sep 11 | 125 |
| Bedford 3 Se | 6,355 ft | A freeze is possible in any month | ||||
| Big Horn | 4,208 ft | May 17 | May 31 | Sep 28 | Sep 13 | 132 |
| Big Piney Marbleton Ap | 6,970 ft | A freeze is possible in any month | ||||
| Billy Creek | 4,975 ft | May 19 | May 31 | Sep 21 | Sep 6 | 123 |
| Bitter Creek 4 Ne | 6,722 ft | Jun 1 | Jun 21 | Sep 16 | Sep 2 | 106 |
| Black Mtn | 5,635 ft | May 14 | Jun 1 | Oct 3 | Sep 20 | 140 |
| Bondurant | 6,693 ft | A freeze is possible in any month | ||||
| Boulder Rearing Stn | 6,940 ft | A freeze is possible in any month | ||||
| Boysen Dam | 4,875 ft | May 5 | May 20 | Oct 7 | Sep 24 | 153 |
| Buckboard Marina | 6,080 ft | May 24 | Jun 8 | Sep 23 | Sep 8 | 118 |
| Buffalo Bill Dam | 5,160 ft | May 17 | Jun 3 | Oct 3 | Sep 18 | 136 |
| Buffalo Johnson Co Ap | 4,967 ft | May 13 | May 28 | Oct 1 | Sep 19 | 141 |
| Buffalo | 4,639 ft | May 24 | Jun 9 | Sep 21 | Sep 7 | 118 |
| Burgess Junction | 8,060 ft | A freeze is possible in any month | ||||
| Burris | 6,125 ft | Jun 1 | Jun 19 | Sep 14 | Sep 1 | 104 |
| Carpenter 3n | 5,437 ft | May 14 | May 27 | Sep 26 | Sep 12 | 133 |
| Casper 1sw | 5,143 ft | May 12 | May 26 | Oct 1 | Sep 18 | 143 |
| Casper Natrona Co Ap | 5,338 ft | May 26 | Jun 10 | Sep 22 | Sep 5 | 117 |
| Casper Wwtp | 5,097 ft | May 10 | May 24 | Sep 29 | Sep 14 | 138 |
| Centennial 1ne | 8,170 ft | Jun 2 | Jun 20 | Sep 19 | Sep 3 | 106 |
| Cheyenne Wfo | 6,119 ft | May 14 | May 28 | Oct 1 | Sep 17 | 139 |
| Cheyenne | 6,128 ft | May 12 | May 26 | Oct 1 | Sep 18 | 141 |
| Chugwater | 5,304 ft | May 18 | Jun 2 | Sep 24 | Sep 9 | 129 |
| Church Buttes Gas Plt | 7,079 ft | May 25 | Jun 11 | Sep 27 | Sep 14 | 124 |
| Clark 3ne | 4,117 ft | May 18 | Jun 4 | Sep 22 | Sep 8 | 125 |
| Clearmont 5 Sw | 3,995 ft | May 24 | Jun 8 | Sep 16 | Sep 3 | 114 |
| Cody 12se | 5,248 ft | May 24 | Jun 11 | Sep 15 | Sep 1 | 114 |
| Cody 21 Sw | 5,840 ft | May 29 | Jun 17 | Sep 18 | Sep 3 | 110 |
| Colony | 3,480 ft | May 7 | May 21 | Oct 3 | Sep 19 | 149 |
| Cora | 7,347 ft | A freeze is possible in any month | ||||
| Daniel Fish Hatchery | 7,341 ft | A freeze is possible in any month | ||||
| Darwin Rch | 8,190 ft | A freeze is possible in any month | ||||
| Dayton | 3,920 ft | May 24 | Jun 7 | Sep 18 | Sep 2 | 114 |
| Deaver | 4,105 ft | May 6 | May 20 | Oct 1 | Sep 19 | 148 |
| Devils Twr #2 | 3,862 ft | May 23 | Jun 6 | Sep 20 | Sep 4 | 118 |
| Dillinger | 4,310 ft | May 25 | Jun 8 | Sep 17 | Sep 3 | 113 |
| Diversion Dam | 5,578 ft | May 21 | Jun 6 | Sep 20 | Sep 5 | 119 |
| Double Four Rch | 6,120 ft | Jun 2 | Jun 25 | Sep 9 | Aug 26 | 99 |
| Douglas 1 Se | 4,870 ft | May 19 | Jun 2 | Sep 23 | Sep 10 | 126 |
| Douglas Converse Co Ap | 4,929 ft | May 23 | Jun 7 | Sep 22 | Sep 9 | 122 |
| Dubois | 6,955 ft | A freeze is possible in any month | ||||
| Dull Ctr 1se | 4,415 ft | May 15 | May 28 | Sep 27 | Sep 13 | 133 |
| Echeta 2 Nw | 4,000 ft | May 21 | Jun 3 | Sep 23 | Sep 8 | 123 |
| Elk Mtn | 7,265 ft | May 28 | Jun 13 | Sep 13 | Aug 30 | 108 |
| Emblem | 4,448 ft | May 12 | May 27 | Sep 28 | Sep 14 | 136 |
| Evanston 1 E | 6,825 ft | Jun 12 | Jul 2 | Sep 12 | Aug 26 | 90 |
| Evanston Burns Fld | 7,163 ft | Jun 3 | Jun 17 | Sep 25 | Sep 11 | 113 |
| Farson 2nne | 6,620 ft | A freeze is possible in any month | ||||
| Fontenelle Dam | 6,485 ft | A freeze is possible in any month | ||||
| Fossil Butte | 6,785 ft | A freeze is possible in any month | ||||
| Gillette 4se | 4,640 ft | May 15 | May 27 | Oct 1 | Sep 15 | 136 |
| Gillette Campbell Ap | 4,354 ft | May 22 | Jun 4 | Sep 25 | Sep 9 | 125 |
| Glendo 6ne | 4,739 ft | May 25 | Jun 11 | Sep 15 | Sep 4 | 112 |
| Glendo Rsvr Usbr | 4,780 ft | May 9 | May 24 | Oct 5 | Sep 21 | 148 |
| Green Rvr | 6,160 ft | May 24 | Jun 10 | Sep 22 | Sep 7 | 120 |
| Greybull S Big Horn Ap | 3,933 ft | May 4 | May 18 | Oct 1 | Sep 18 | 149 |
| Greybull | 3,787 ft | May 11 | May 24 | Sep 23 | Sep 11 | 133 |
| Guernsey 2nw | 4,480 ft | May 7 | May 21 | Oct 6 | Sep 23 | 152 |
| Guernsey Dam #2 | 4,355 ft | May 11 | May 25 | Oct 3 | Sep 19 | 144 |
| Heart Mtn | 4,790 ft | May 15 | Jun 1 | Sep 25 | Sep 11 | 132 |
| Hecla 1e | 6,690 ft | May 27 | Jun 13 | Sep 19 | Sep 3 | 115 |
| Hulett | 3,758 ft | May 17 | May 30 | Sep 23 | Sep 8 | 128 |
| Jackson | 6,210 ft | A freeze is possible in any month | ||||
| Jeffrey City | 6,319 ft | Jun 1 | Jun 16 | Sep 13 | Sep 1 | 104 |
| Kaycee | 4,660 ft | May 18 | May 31 | Sep 25 | Sep 11 | 129 |
| Kemmerer 2n | 6,937 ft | A freeze is possible in any month | ||||
| La Barge | 6,598 ft | Jun 9 | Jun 27 | Sep 4 | Aug 21 | 84 |
| La Grange | 4,590 ft | May 14 | May 29 | Oct 1 | Sep 15 | 137 |
| Lake Yellowstone | 7,892 ft | A freeze is possible in any month | ||||
| Lamar Rs | 6,575 ft | A freeze is possible in any month | ||||
| Lance Creek 11nne | 4,204 ft | May 17 | Jun 3 | Sep 25 | Sep 9 | 129 |
| Lander 11 Sse | 5,773 ft | May 13 | Jun 1 | Oct 2 | Sep 20 | 140 |
| Lander Hunt Fld Ap | 5,592 ft | May 18 | Jun 3 | Sep 27 | Sep 13 | 131 |
| Laramie 2 Nw | 7,140 ft | Jun 7 | Jun 29 | Sep 4 | Aug 17 | 88 |
| Laramie 4se | 7,390 ft | May 22 | Jun 4 | Sep 28 | Sep 16 | 126 |
| Laramie Rgnl Ap | 7,266 ft | Jun 2 | Jun 18 | Sep 15 | Sep 3 | 102 |
| Leiter 9n | 4,160 ft | May 14 | May 29 | Sep 30 | Sep 17 | 137 |
| Leo 6 Sw | 6,035 ft | May 20 | Jun 13 | Sep 28 | Sep 9 | 128 |
| Lingle 2wsw | 4,158 ft | May 20 | Jun 7 | Sep 22 | Sep 8 | 122 |
| Lovell | 3,847 ft | May 9 | May 25 | Sep 29 | Sep 16 | 142 |
| Lusk 2 Sw | 5,090 ft | May 23 | Jun 8 | Sep 20 | Sep 4 | 119 |
| Lusk 25ne | 4,136 ft | May 14 | May 27 | Oct 1 | Sep 19 | 139 |
| Medicine Bow | 6,635 ft | Jun 1 | Jun 19 | Sep 8 | Aug 28 | 97 |
| Midwest | 4,860 ft | May 22 | Jun 6 | Sep 22 | Sep 8 | 121 |
| Moorcroft 3s | 4,325 ft | May 22 | Jun 9 | Sep 28 | Sep 11 | 127 |
| Moose 1 Nne | 6,466 ft | Jun 24 | Jul 11 | Aug 28 | Aug 8 | 63 |
| Moose | 6,444 ft | Jun 20 | Jul 9 | Aug 31 | Aug 12 | 70 |
| Moran 5wnw | 6,805 ft | A freeze is possible in any month | ||||
| Mtn View | 6,800 ft | Jun 14 | Jul 1 | Sep 9 | Aug 23 | 84 |
| Muddy Gap | 6,248 ft | May 21 | Jun 10 | Sep 27 | Sep 12 | 126 |
| Newcastle | 4,415 ft | May 13 | May 26 | Oct 3 | Sep 17 | 143 |
| Old Faithful | 7,351 ft | A freeze is possible in any month | ||||
| Old Ft Laramie | 4,250 ft | May 14 | May 27 | Sep 26 | Sep 12 | 134 |
| Pahaska | 6,692 ft | A freeze is possible in any month | ||||
| Pathfinder Dam | 5,923 ft | May 9 | May 23 | Oct 7 | Sep 22 | 148 |
| Pavillion | 5,480 ft | May 14 | May 29 | Sep 30 | Sep 18 | 139 |
| Phillips | 4,982 ft | May 21 | Jun 7 | Sep 21 | Sep 8 | 121 |
| Pine Bluffs 1ese | 5,058 ft | May 10 | May 24 | Oct 1 | Sep 17 | 142 |
| Pine Bluffs 5w | 5,180 ft | May 16 | Jun 1 | Sep 27 | Sep 13 | 132 |
| Pinedale | 7,210 ft | A freeze is possible in any month | ||||
| Powder River #2 | 5,700 ft | May 23 | Jun 5 | Sep 20 | Sep 7 | 121 |
| Powder Rvr (School) | 5,722 ft | May 30 | Jun 13 | Sep 22 | Sep 8 | 115 |
| Powell Fld Stn | 4,372 ft | May 19 | Jun 4 | Sep 20 | Sep 7 | 123 |
| Rawlins 1n | 6,908 ft | May 17 | May 31 | Oct 2 | Sep 22 | 138 |
| Rawlins Muni Ap | 6,736 ft | Jun 1 | Jun 17 | Sep 15 | Sep 3 | 105 |
| Redbird | 3,890 ft | May 16 | May 31 | Sep 24 | Sep 10 | 130 |
| Riverton | 4,955 ft | May 12 | May 26 | Sep 24 | Sep 11 | 132 |
| Riverton | 5,568 ft | May 16 | May 31 | Sep 28 | Sep 15 | 133 |
| Rochelle 7ene | 4,239 ft | May 25 | Jun 11 | Sep 14 | Aug 31 | 110 |
| Rock Springs Ap | 6,741 ft | May 22 | Jun 9 | Sep 28 | Sep 14 | 126 |
| Rock Springs Fire Dept | 6,270 ft | May 24 | Jun 9 | Sep 24 | Sep 9 | 121 |
| Sage 4 Nnw | 6,210 ft | A freeze is possible in any month | ||||
| Saratoga 4n | 6,801 ft | Jun 12 | Jun 30 | Sep 7 | Aug 22 | 83 |
| Saratoga | 6,790 ft | Jun 2 | Jun 21 | Sep 12 | Aug 12 | 101 |
| Seminoe Rsvr Usbr | 6,975 ft | May 12 | May 25 | Oct 4 | Sep 23 | 143 |
| Shell | 4,242 ft | May 16 | Jun 3 | Sep 24 | Sep 10 | 130 |
| Sheridan Co Ap | 3,945 ft | May 21 | Jun 6 | Sep 23 | Sep 9 | 123 |
| Sheridan Fld Stn | 3,750 ft | May 18 | Jun 2 | Sep 24 | Sep 9 | 127 |
| Shirley Basin | 7,057 ft | A freeze is possible in any month | ||||
| Shoshoni | 4,837 ft | May 7 | May 18 | Oct 3 | Sep 23 | 145 |
| Snake Rvr | 6,882 ft | A freeze is possible in any month | ||||
| South Pass City | 7,840 ft | A freeze is possible in any month | ||||
| Story | 5,168 ft | May 24 | Jun 9 | Sep 23 | Sep 8 | 120 |
| Sundance 8 Nnw | 5,792 ft | May 23 | Jun 3 | Sep 24 | Sep 7 | 121 |
| Sundance | 4,695 ft | May 21 | Jun 5 | Sep 25 | Sep 7 | 124 |
| Sunshine 3ne | 6,224 ft | A freeze is possible in any month | ||||
| Sybille Rsch Unit | 6,086 ft | May 22 | Jun 5 | Sep 24 | Sep 9 | 125 |
| Tensleep 16sse | 4,680 ft | May 22 | Jun 7 | Sep 18 | Sep 4 | 117 |
| Tensleep 4ne | 4,748 ft | May 10 | May 26 | Oct 1 | Sep 18 | 141 |
| Thermopolis 21wnw | 5,510 ft | May 29 | Jun 19 | Sep 17 | Sep 3 | 110 |
| Thermopolis 9ne | 4,282 ft | May 24 | Jun 9 | Sep 16 | Sep 4 | 112 |
| Thermopolis | 4,321 ft | May 5 | May 19 | Oct 5 | Sep 23 | 152 |
| Torrington 29n | 4,860 ft | May 17 | May 31 | Sep 28 | Sep 15 | 133 |
| Torrington Exp Farm | 4,098 ft | May 14 | May 28 | Sep 24 | Sep 10 | 130 |
| Torrington Muni Ap | 4,205 ft | May 11 | May 26 | Sep 29 | Sep 16 | 139 |
| Tower Falls | 6,275 ft | A freeze is possible in any month | ||||
| Upton | 4,320 ft | May 20 | Jun 4 | Sep 23 | Sep 7 | 123 |
| Wamsutter | 6,740 ft | Jun 5 | Jun 23 | Sep 14 | Sep 1 | 101 |
| Wapiti 1wsw | 5,558 ft | May 27 | Jun 12 | Sep 25 | Sep 7 | 121 |
| Weston 1 E | 3,738 ft | May 23 | Jun 5 | Sep 18 | Sep 1 | 118 |
| Whalen Dam Usbr | 4,294 ft | May 7 | May 24 | Oct 3 | Sep 21 | 146 |
| Wheatland 4 N | 4,638 ft | May 19 | Jun 2 | Sep 22 | Sep 8 | 125 |
| Worland | 4,058 ft | May 4 | May 18 | Oct 1 | Sep 21 | 149 |
| Worland | 4,172 ft | May 13 | May 27 | Sep 26 | Sep 14 | 133 |
| Wright 12w | 5,020 ft | May 25 | Jun 8 | Sep 23 | Sep 8 | 120 |
| Yellowstone Lake | 7,835 ft | A freeze is possible in any month | ||||
| Yellowstone Park Mammoth | 6,195 ft | Jun 3 | Jun 19 | Sep 14 | Aug 31 | 102 |
| Yoder 5 W | 4,330 ft | May 15 | Jun 2 | Sep 27 | Sep 12 | 132 |
Plan your garden with these dates
Enter your ZIP code in the planner: it picks the nearest of these stations and dates every crop in your beds from its frosts. Free, in your browser.
Questions
When is the last frost in Wyoming?
It depends on where you are. The typical last spring frost at Wyoming's NOAA stations ranges from April 28 to June 24, and half of them have had it by May 20. Enter your ZIP code above for the station nearest you.
When is the first frost in Wyoming?
Typically between August 28 and October 10, depending on the station; the median is September 24. Plan fall crops back from your own station's date.
What do "typical" and "safer" mean?
With the typical (50%) last-frost date, half of years still have a frost after it. With the safer (10%) date, only one year in ten does. In fall it's the other way around: the safer date is the earlier one.
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