Frost Dates in Wyoming
Across 129 NOAA weather stations in Wyoming, the average last spring frost falls between April 28 at Basin and June 24 at Moose 1 NNE. At a typical Wyoming station it is around May 20, with the first fall frost around September 24 and a frost-free season of about 125 days.
Find the frost dates for your ZIP code
A typical Wyoming season
What shapes frost dates in Wyoming
- The frost-free season ranges from 63 days at Moose 1 NNE to 164 days at Basin.
- Elevation matters: Centennial 1NE, at 8,170 ft, averages its last frost on June 2, while Colony, at 3,480 ft, averages May 7.
- Gardens in valleys and low spots, where cold air settles, often frost a week or more later in spring than the nearest station.
Frost dates at major airports
| Station | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|
| Buffalo Johnson Co Airport | May 13 | May 28 | Oct 1 | 141 |
| Casper Natrona Co Airport | May 26 | Jun 10 | Sep 22 | 117 |
| Cheyenne | May 12 | May 26 | Oct 1 | 141 |
| Douglas Converse Co Airport | May 23 | Jun 7 | Sep 22 | 122 |
| Evanston Burns Fld | Jun 3 | Jun 17 | Sep 25 | 113 |
| Gillette Campbell Airport | May 22 | Jun 4 | Sep 25 | 125 |
| Greybull S Big Horn Airport | May 4 | May 18 | Oct 1 | 149 |
| Lander 11 SSE | May 13 | Jun 1 | Oct 2 | 140 |
| Lander Hunt Fld Airport | May 18 | Jun 3 | Sep 27 | 131 |
| Laramie Rgnl Airport | Jun 2 | Jun 18 | Sep 15 | 102 |
| Moorcroft 3S | May 22 | Jun 9 | Sep 28 | 127 |
| Moose 1 NNE | Jun 24 | Jul 11 | Aug 28 | 63 |
| Rawlins Muni Airport | Jun 1 | Jun 17 | Sep 15 | 105 |
| Riverton | May 16 | May 31 | Sep 28 | 133 |
| Rock Springs Airport | May 22 | Jun 9 | Sep 28 | 126 |
| Sheridan Co Airport | May 21 | Jun 6 | Sep 23 | 123 |
| Sundance 8 NNW | May 23 | Jun 3 | Sep 24 | 121 |
| Torrington Muni Airport | May 11 | May 26 | Sep 29 | 139 |
| Worland | May 13 | May 27 | Sep 26 | 133 |
All 129 weather stations in Wyoming
| Station | Elevation (ft) | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|---|
| Afton | 6,248 | Jun 20 | Jul 7 | Sep 1 | 71 |
| Albin | 5,345 | May 14 | May 25 | Oct 2 | 142 |
| Alta 1 NNW | 6,440 | Jun 14 | Jul 4 | Sep 11 | 85 |
| Archer | 6,010 | May 21 | Jun 6 | Sep 24 | 124 |
| Baggs | 6,319 | Jun 1 | Jun 18 | Sep 18 | 108 |
| Basin | 3,840 | Apr 28 | May 11 | Oct 10 | 164 |
| Bates Creek #2 | 6,042 | May 22 | Jun 6 | Sep 26 | 125 |
| Big Horn | 4,208 | May 17 | May 31 | Sep 28 | 132 |
| Billy Creek | 4,975 | May 19 | May 31 | Sep 21 | 123 |
| Bitter Creek 4 NE | 6,722 | Jun 1 | Jun 21 | Sep 16 | 106 |
| Black Mtn | 5,635 | May 14 | Jun 1 | Oct 3 | 140 |
| Boysen Dam | 4,875 | May 5 | May 20 | Oct 7 | 153 |
| Buckboard Marina | 6,080 | May 24 | Jun 8 | Sep 23 | 118 |
| Buffalo | 4,639 | May 24 | Jun 9 | Sep 21 | 118 |
| Buffalo Bill Dam | 5,160 | May 17 | Jun 3 | Oct 3 | 136 |
| Buffalo Johnson Co Airport | 4,967 | May 13 | May 28 | Oct 1 | 141 |
| Burris | 6,125 | Jun 1 | Jun 19 | Sep 14 | 104 |
| Carpenter 3N | 5,437 | May 14 | May 27 | Sep 26 | 133 |
| Casper 1SW | 5,143 | May 12 | May 26 | Oct 1 | 143 |
| Casper Natrona Co Airport | 5,338 | May 26 | Jun 10 | Sep 22 | 117 |
| Casper Wwtp | 5,097 | May 10 | May 24 | Sep 29 | 138 |
| Centennial 1NE | 8,170 | Jun 2 | Jun 20 | Sep 19 | 106 |
| Cheyenne | 6,128 | May 12 | May 26 | Oct 1 | 141 |
| Cheyenne Wfo | 6,119 | May 14 | May 28 | Oct 1 | 139 |
| Chugwater | 5,304 | May 18 | Jun 2 | Sep 24 | 129 |
| Church Buttes Gas Plt | 7,079 | May 25 | Jun 11 | Sep 27 | 124 |
| Clark 3NE | 4,117 | May 18 | Jun 4 | Sep 22 | 125 |
| Clearmont 5 SW | 3,995 | May 24 | Jun 8 | Sep 16 | 114 |
| Cody | 5,280 | May 12 | May 27 | Oct 1 | 140 |
| Cody 12SE | 5,248 | May 24 | Jun 11 | Sep 15 | 114 |
| Cody 21 SW | 5,840 | May 29 | Jun 17 | Sep 18 | 110 |
| Colony | 3,480 | May 7 | May 21 | Oct 3 | 149 |
| Dayton | 3,920 | May 24 | Jun 7 | Sep 18 | 114 |
| Deaver | 4,105 | May 6 | May 20 | Oct 1 | 148 |
| Devils Twr #2 | 3,862 | May 23 | Jun 6 | Sep 20 | 118 |
| Dillinger | 4,310 | May 25 | Jun 8 | Sep 17 | 113 |
| Diversion Dam | 5,578 | May 21 | Jun 6 | Sep 20 | 119 |
| Double Four Rch | 6,120 | Jun 2 | Jun 25 | Sep 9 | 99 |
| Douglas 1 SE | 4,870 | May 19 | Jun 2 | Sep 23 | 126 |
| Douglas Converse Co Airport | 4,929 | May 23 | Jun 7 | Sep 22 | 122 |
| Dull Ctr 1SE | 4,415 | May 15 | May 28 | Sep 27 | 133 |
| Echeta 2 NW | 4,000 | May 21 | Jun 3 | Sep 23 | 123 |
| Elk Mtn | 7,265 | May 28 | Jun 13 | Sep 13 | 108 |
| Emblem | 4,448 | May 12 | May 27 | Sep 28 | 136 |
| Evanston 1 E | 6,825 | Jun 12 | Jul 2 | Sep 12 | 90 |
| Evanston Burns Fld | 7,163 | Jun 3 | Jun 17 | Sep 25 | 113 |
| Gillette 4SE | 4,640 | May 15 | May 27 | Oct 1 | 136 |
| Gillette Campbell Airport | 4,354 | May 22 | Jun 4 | Sep 25 | 125 |
| Glendo 6NE | 4,739 | May 25 | Jun 11 | Sep 15 | 112 |
| Glendo Rsvr Usbr | 4,780 | May 9 | May 24 | Oct 5 | 148 |
| Green Rvr | 6,160 | May 24 | Jun 10 | Sep 22 | 120 |
| Greybull | 3,787 | May 11 | May 24 | Sep 23 | 133 |
| Greybull S Big Horn Airport | 3,933 | May 4 | May 18 | Oct 1 | 149 |
| Guernsey 2NW | 4,480 | May 7 | May 21 | Oct 6 | 152 |
| Guernsey Dam #2 | 4,355 | May 11 | May 25 | Oct 3 | 144 |
| Heart Mtn | 4,790 | May 15 | Jun 1 | Sep 25 | 132 |
| Hecla 1E | 6,690 | May 27 | Jun 13 | Sep 19 | 115 |
| Hulett | 3,758 | May 17 | May 30 | Sep 23 | 128 |
| Jeffrey City | 6,319 | Jun 1 | Jun 16 | Sep 13 | 104 |
| Kaycee | 4,660 | May 18 | May 31 | Sep 25 | 129 |
| La Barge | 6,598 | Jun 9 | Jun 27 | Sep 4 | 84 |
| La Grange | 4,590 | May 14 | May 29 | Oct 1 | 137 |
| Lance Creek 11NNE | 4,204 | May 17 | Jun 3 | Sep 25 | 129 |
| Lander 11 SSE | 5,773 | May 13 | Jun 1 | Oct 2 | 140 |
| Lander Hunt Fld Airport | 5,592 | May 18 | Jun 3 | Sep 27 | 131 |
| Laramie 2 NW | 7,140 | Jun 7 | Jun 29 | Sep 4 | 88 |
| Laramie 4SE | 7,390 | May 22 | Jun 4 | Sep 28 | 126 |
| Laramie Rgnl Airport | 7,266 | Jun 2 | Jun 18 | Sep 15 | 102 |
| Leiter 9N | 4,160 | May 14 | May 29 | Sep 30 | 137 |
| Leo 6 SW | 6,035 | May 20 | Jun 13 | Sep 28 | 128 |
| Lingle 2WSW | 4,158 | May 20 | Jun 7 | Sep 22 | 122 |
| Lovell | 3,847 | May 9 | May 25 | Sep 29 | 142 |
| Lusk 2 SW | 5,090 | May 23 | Jun 8 | Sep 20 | 119 |
| Lusk 25NE | 4,136 | May 14 | May 27 | Oct 1 | 139 |
| Medicine Bow | 6,635 | Jun 1 | Jun 19 | Sep 8 | 97 |
| Midwest | 4,860 | May 22 | Jun 6 | Sep 22 | 121 |
| Moorcroft 3S | 4,325 | May 22 | Jun 9 | Sep 28 | 127 |
| Moose | 6,444 | Jun 20 | Jul 9 | Aug 31 | 70 |
| Moose 1 NNE | 6,466 | Jun 24 | Jul 11 | Aug 28 | 63 |
| Mtn View | 6,800 | Jun 14 | Jul 1 | Sep 9 | 84 |
| Muddy Gap | 6,248 | May 21 | Jun 10 | Sep 27 | 126 |
| Newcastle | 4,415 | May 13 | May 26 | Oct 3 | 143 |
| Old Ft Laramie | 4,250 | May 14 | May 27 | Sep 26 | 134 |
| Pathfinder Dam | 5,923 | May 9 | May 23 | Oct 7 | 148 |
| Pavillion | 5,480 | May 14 | May 29 | Sep 30 | 139 |
| Phillips | 4,982 | May 21 | Jun 7 | Sep 21 | 121 |
| Pine Bluffs 1ESE | 5,058 | May 10 | May 24 | Oct 1 | 142 |
| Pine Bluffs 5W | 5,180 | May 16 | Jun 1 | Sep 27 | 132 |
| Powder River #2 | 5,700 | May 23 | Jun 5 | Sep 20 | 121 |
| Powder Rvr (school) | 5,722 | May 30 | Jun 13 | Sep 22 | 115 |
| Powell Fld Stn | 4,372 | May 19 | Jun 4 | Sep 20 | 123 |
| Rawlins 1N | 6,908 | May 17 | May 31 | Oct 2 | 138 |
| Rawlins Muni Airport | 6,736 | Jun 1 | Jun 17 | Sep 15 | 105 |
| Redbird | 3,890 | May 16 | May 31 | Sep 24 | 130 |
| Riverton | 4,955 | May 12 | May 26 | Sep 24 | 132 |
| Riverton | 5,568 | May 16 | May 31 | Sep 28 | 133 |
| Rochelle 7ENE | 4,239 | May 25 | Jun 11 | Sep 14 | 110 |
| Rock Springs Airport | 6,741 | May 22 | Jun 9 | Sep 28 | 126 |
| Rock Springs Fire Dept | 6,270 | May 24 | Jun 9 | Sep 24 | 121 |
| Saratoga | 6,790 | Jun 2 | Jun 21 | Sep 12 | 101 |
| Saratoga 4N | 6,801 | Jun 12 | Jun 30 | Sep 7 | 83 |
| Seminoe Rsvr Usbr | 6,975 | May 12 | May 25 | Oct 4 | 143 |
| Shell | 4,242 | May 16 | Jun 3 | Sep 24 | 130 |
| Sheridan Co Airport | 3,945 | May 21 | Jun 6 | Sep 23 | 123 |
| Sheridan Fld Stn | 3,750 | May 18 | Jun 2 | Sep 24 | 127 |
| Shoshoni | 4,837 | May 7 | May 18 | Oct 3 | 145 |
| Story | 5,168 | May 24 | Jun 9 | Sep 23 | 120 |
| Sundance | 4,695 | May 21 | Jun 5 | Sep 25 | 124 |
| Sundance 8 NNW | 5,792 | May 23 | Jun 3 | Sep 24 | 121 |
| Sybille Rsch Unit | 6,086 | May 22 | Jun 5 | Sep 24 | 125 |
| Tensleep 16SSE | 4,680 | May 22 | Jun 7 | Sep 18 | 117 |
| Tensleep 4NE | 4,748 | May 10 | May 26 | Oct 1 | 141 |
| Thermopolis | 4,321 | May 5 | May 19 | Oct 5 | 152 |
| Thermopolis 21WNW | 5,510 | May 29 | Jun 19 | Sep 17 | 110 |
| Thermopolis 9NE | 4,282 | May 24 | Jun 9 | Sep 16 | 112 |
| Torrington 29N | 4,860 | May 17 | May 31 | Sep 28 | 133 |
| Torrington Exp Farm | 4,098 | May 14 | May 28 | Sep 24 | 130 |
| Torrington Muni Airport | 4,205 | May 11 | May 26 | Sep 29 | 139 |
| Upton | 4,320 | May 20 | Jun 4 | Sep 23 | 123 |
| Wamsutter | 6,740 | Jun 5 | Jun 23 | Sep 14 | 101 |
| Wapiti 1WSW | 5,558 | May 27 | Jun 12 | Sep 25 | 121 |
| Weston 1 E | 3,738 | May 23 | Jun 5 | Sep 18 | 118 |
| Whalen Dam Usbr | 4,294 | May 7 | May 24 | Oct 3 | 146 |
| Wheatland 4 N | 4,638 | May 19 | Jun 2 | Sep 22 | 125 |
| Worland | 4,058 | May 4 | May 18 | Oct 1 | 149 |
| Worland | 4,172 | May 13 | May 27 | Sep 26 | 133 |
| Wright 12W | 5,020 | May 25 | Jun 8 | Sep 23 | 120 |
| Yellowstone Park Mammoth | 6,195 | Jun 3 | Jun 19 | Sep 14 | 102 |
| Yoder 5 W | 4,330 | May 15 | Jun 2 | Sep 27 | 132 |
No station matches that name. Try a nearby town, or look up your ZIP code above.
Last frost and first frost are averages (a 50% chance of frost later in spring or earlier in fall). Safer date is the spring date with only a 10% chance of a later frost.
Using these dates
Plant hardy crops like peas and spinach several weeks before your last frost, and tender crops like tomatoes and peppers after it, once nights stay above 50°F. The Seed Starting Calculator turns your frost date into sowing and planting dates, and When to Plant Tomatoes explains the timing in detail.
Data: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, 32°F threshold.
Frost dates in other states
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