SowByZipgarden planner

Wyoming frost dates

Across 129 NOAA climate stations in Wyoming, the median last spring frost (32°F) ranges from Apr 28 at Basin to Jun 24 at Moose 1 Nne; the typical station sees its last frost around May 20 and its first fall frost around Sep 24.

“Median” dates have a 50% chance of a later spring frost or an earlier fall frost. “10% risk” dates are the safer choice for tender plants: only 1 year in 10 has frost beyond them. Source: NOAA NCEI 1991–2020 Climate Normals. Elevation matters: within a state, frost dates can differ by a month or more between valleys and hills.

StationElevationLast frost (median)Last frost (10% risk)First frost (median)First frost (10% risk)Growing season
Afton6,248 ftJun 20Jul 7Sep 1Aug 1271 days
Albin5,345 ftMay 14May 25Oct 2Sep 18142 days
Alta 1 Nnw6,440 ftJun 14Jul 4Sep 11Aug 2885 days
Archer6,010 ftMay 21Jun 6Sep 24Sep 8124 days
Baggs6,319 ftJun 1Jun 18Sep 18Sep 4108 days
Basin3,840 ftApr 28May 11Oct 10Sep 26164 days
Bates Creek #26,042 ftMay 22Jun 6Sep 26Sep 11125 days
Big Horn4,208 ftMay 17May 31Sep 28Sep 13132 days
Billy Creek4,975 ftMay 19May 31Sep 21Sep 6123 days
Bitter Creek 4 Ne6,722 ftJun 1Jun 21Sep 16Sep 2106 days
Black Mtn5,635 ftMay 14Jun 1Oct 3Sep 20140 days
Boysen Dam4,875 ftMay 5May 20Oct 7Sep 24153 days
Buckboard Marina6,080 ftMay 24Jun 8Sep 23Sep 8118 days
Buffalo4,639 ftMay 24Jun 9Sep 21Sep 7118 days
Buffalo Bill Dam5,160 ftMay 17Jun 3Oct 3Sep 18136 days
Buffalo Johnson Co AP4,967 ftMay 13May 28Oct 1Sep 19141 days
Burris6,125 ftJun 1Jun 19Sep 14Sep 1104 days
Carpenter 3N5,437 ftMay 14May 27Sep 26Sep 12133 days
Casper 1SW5,143 ftMay 12May 26Oct 1Sep 18143 days
Casper Natrona Co AP5,338 ftMay 26Jun 10Sep 22Sep 5117 days
Casper Wwtp5,097 ftMay 10May 24Sep 29Sep 14138 days
Centennial 1NE8,170 ftJun 2Jun 20Sep 19Sep 3106 days
Cheyenne6,128 ftMay 12May 26Oct 1Sep 18141 days
Cheyenne Wfo6,119 ftMay 14May 28Oct 1Sep 17139 days
Chugwater5,304 ftMay 18Jun 2Sep 24Sep 9129 days
Church Buttes Gas Plt7,079 ftMay 25Jun 11Sep 27Sep 14124 days
Clark 3NE4,117 ftMay 18Jun 4Sep 22Sep 8125 days
Clearmont 5 Sw3,995 ftMay 24Jun 8Sep 16Sep 3114 days
Cody5,280 ftMay 12May 27Oct 1Sep 17140 days
Cody 12SE5,248 ftMay 24Jun 11Sep 15Sep 1114 days
Cody 21 Sw5,840 ftMay 29Jun 17Sep 18Sep 3110 days
Colony3,480 ftMay 7May 21Oct 3Sep 19149 days
Dayton3,920 ftMay 24Jun 7Sep 18Sep 2114 days
Deaver4,105 ftMay 6May 20Oct 1Sep 19148 days
Devils Twr #23,862 ftMay 23Jun 6Sep 20Sep 4118 days
Dillinger4,310 ftMay 25Jun 8Sep 17Sep 3113 days
Diversion Dam5,578 ftMay 21Jun 6Sep 20Sep 5119 days
Double Four Rch6,120 ftJun 2Jun 25Sep 9Aug 2699 days
Douglas 1 Se4,870 ftMay 19Jun 2Sep 23Sep 10126 days
Douglas Converse Co AP4,929 ftMay 23Jun 7Sep 22Sep 9122 days
Dull Ctr 1SE4,415 ftMay 15May 28Sep 27Sep 13133 days
Echeta 2 Nw4,000 ftMay 21Jun 3Sep 23Sep 8123 days
Elk Mtn7,265 ftMay 28Jun 13Sep 13Aug 30108 days
Emblem4,448 ftMay 12May 27Sep 28Sep 14136 days
Evanston 1 E6,825 ftJun 12Jul 2Sep 12Aug 2690 days
Evanston Burns Fld7,163 ftJun 3Jun 17Sep 25Sep 11113 days
Gillette 4SE4,640 ftMay 15May 27Oct 1Sep 15136 days
Gillette Campbell AP4,354 ftMay 22Jun 4Sep 25Sep 9125 days
Glendo 6NE4,739 ftMay 25Jun 11Sep 15Sep 4112 days
Glendo Rsvr Usbr4,780 ftMay 9May 24Oct 5Sep 21148 days
Green Rvr6,160 ftMay 24Jun 10Sep 22Sep 7120 days
Greybull3,787 ftMay 11May 24Sep 23Sep 11133 days
Greybull S Big Horn AP3,933 ftMay 4May 18Oct 1Sep 18149 days
Guernsey 2NW4,480 ftMay 7May 21Oct 6Sep 23152 days
Guernsey Dam #24,355 ftMay 11May 25Oct 3Sep 19144 days
Heart Mtn4,790 ftMay 15Jun 1Sep 25Sep 11132 days
Hecla 1E6,690 ftMay 27Jun 13Sep 19Sep 3115 days
Hulett3,758 ftMay 17May 30Sep 23Sep 8128 days
Jeffrey City6,319 ftJun 1Jun 16Sep 13Sep 1104 days
Kaycee4,660 ftMay 18May 31Sep 25Sep 11129 days
La Barge6,598 ftJun 9Jun 27Sep 4Aug 2184 days
La Grange4,590 ftMay 14May 29Oct 1Sep 15137 days
Lance Creek 11NNE4,204 ftMay 17Jun 3Sep 25Sep 9129 days
Lander 11 Sse5,773 ftMay 13Jun 1Oct 2Sep 20140 days
Lander Hunt Fld AP5,592 ftMay 18Jun 3Sep 27Sep 13131 days
Laramie 2 Nw7,140 ftJun 7Jun 29Sep 4Aug 1788 days
Laramie 4SE7,390 ftMay 22Jun 4Sep 28Sep 16126 days
Laramie Rgnl AP7,266 ftJun 2Jun 18Sep 15Sep 3102 days
Leiter 9N4,160 ftMay 14May 29Sep 30Sep 17137 days
Leo 6 Sw6,035 ftMay 20Jun 13Sep 28Sep 9128 days
Lingle 2WSW4,158 ftMay 20Jun 7Sep 22Sep 8122 days
Lovell3,847 ftMay 9May 25Sep 29Sep 16142 days
Lusk 2 Sw5,090 ftMay 23Jun 8Sep 20Sep 4119 days
Lusk 25NE4,136 ftMay 14May 27Oct 1Sep 19139 days
Medicine Bow6,635 ftJun 1Jun 19Sep 8Aug 2897 days
Midwest4,860 ftMay 22Jun 6Sep 22Sep 8121 days
Moorcroft 3S4,325 ftMay 22Jun 9Sep 28Sep 11127 days
Moose6,444 ftJun 20Jul 9Aug 31Aug 1270 days
Moose 1 Nne6,466 ftJun 24Jul 11Aug 28Aug 863 days
Mtn View6,800 ftJun 14Jul 1Sep 9Aug 2384 days
Muddy Gap6,248 ftMay 21Jun 10Sep 27Sep 12126 days
Newcastle4,415 ftMay 13May 26Oct 3Sep 17143 days
Old Ft Laramie4,250 ftMay 14May 27Sep 26Sep 12134 days
Pathfinder Dam5,923 ftMay 9May 23Oct 7Sep 22148 days
Pavillion5,480 ftMay 14May 29Sep 30Sep 18139 days
Phillips4,982 ftMay 21Jun 7Sep 21Sep 8121 days
Pine Bluffs 1ESE5,058 ftMay 10May 24Oct 1Sep 17142 days
Pine Bluffs 5W5,180 ftMay 16Jun 1Sep 27Sep 13132 days
Powder River #25,700 ftMay 23Jun 5Sep 20Sep 7121 days
Powder Rvr (School)5,722 ftMay 30Jun 13Sep 22Sep 8115 days
Powell Fld Stn4,372 ftMay 19Jun 4Sep 20Sep 7123 days
Rawlins 1N6,908 ftMay 17May 31Oct 2Sep 22138 days
Rawlins Muni AP6,736 ftJun 1Jun 17Sep 15Sep 3105 days
Redbird3,890 ftMay 16May 31Sep 24Sep 10130 days
Riverton4,955 ftMay 12May 26Sep 24Sep 11132 days
Riverton5,568 ftMay 16May 31Sep 28Sep 15133 days
Rochelle 7ENE4,239 ftMay 25Jun 11Sep 14Aug 31110 days
Rock Springs AP6,741 ftMay 22Jun 9Sep 28Sep 14126 days
Rock Springs Fire Dept6,270 ftMay 24Jun 9Sep 24Sep 9121 days
Saratoga6,790 ftJun 2Jun 21Sep 12Aug 12101 days
Saratoga 4N6,801 ftJun 12Jun 30Sep 7Aug 2283 days
Seminoe Rsvr Usbr6,975 ftMay 12May 25Oct 4Sep 23143 days
Shell4,242 ftMay 16Jun 3Sep 24Sep 10130 days
Sheridan Co AP3,945 ftMay 21Jun 6Sep 23Sep 9123 days
Sheridan Fld Stn3,750 ftMay 18Jun 2Sep 24Sep 9127 days
Shoshoni4,837 ftMay 7May 18Oct 3Sep 23145 days
Story5,168 ftMay 24Jun 9Sep 23Sep 8120 days
Sundance4,695 ftMay 21Jun 5Sep 25Sep 7124 days
Sundance 8 Nnw5,792 ftMay 23Jun 3Sep 24Sep 7121 days
Sybille Rsch Unit6,086 ftMay 22Jun 5Sep 24Sep 9125 days
Tensleep 16SSE4,680 ftMay 22Jun 7Sep 18Sep 4117 days
Tensleep 4NE4,748 ftMay 10May 26Oct 1Sep 18141 days
Thermopolis4,321 ftMay 5May 19Oct 5Sep 23152 days
Thermopolis 21WNW5,510 ftMay 29Jun 19Sep 17Sep 3110 days
Thermopolis 9NE4,282 ftMay 24Jun 9Sep 16Sep 4112 days
Torrington 29N4,860 ftMay 17May 31Sep 28Sep 15133 days
Torrington Exp Farm4,098 ftMay 14May 28Sep 24Sep 10130 days
Torrington Muni AP4,205 ftMay 11May 26Sep 29Sep 16139 days
Upton4,320 ftMay 20Jun 4Sep 23Sep 7123 days
Wamsutter6,740 ftJun 5Jun 23Sep 14Sep 1101 days
Wapiti 1WSW5,558 ftMay 27Jun 12Sep 25Sep 7121 days
Weston 1 E3,738 ftMay 23Jun 5Sep 18Sep 1118 days
Whalen Dam Usbr4,294 ftMay 7May 24Oct 3Sep 21146 days
Wheatland 4 N4,638 ftMay 19Jun 2Sep 22Sep 8125 days
Worland4,058 ftMay 4May 18Oct 1Sep 21149 days
Worland4,172 ftMay 13May 27Sep 26Sep 14133 days
Wright 12W5,020 ftMay 25Jun 8Sep 23Sep 8120 days
Yellowstone Park Mammoth6,195 ftJun 3Jun 19Sep 14Aug 31102 days
Yoder 5 W4,330 ftMay 15Jun 2Sep 27Sep 12132 days
Advertisement