A combination of an arctic air mass, a clear sky, a long early January night and a deep, fresh snow pack brought frigid temperatures to much of western and central Wyoming. Four different counties recorded low temperatures under minus 40, including a low of minus 45 East of Rock Springs.
Every event with a place to put it; 15 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS RIW wrote it up.
A combination of an arctic air mass, a clear sky, a long early January night and a deep, fresh snow pack brought frigid temperatures to much of western and central Wyoming. Four different counties recorded low temperatures under minus 40, including a low of minus 45 East of Rock Springs. All eleven counties in the County Warning Area recorded a temperatures of -30 or lower on the night of January 5-6, 2017.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Riverton, WY wrote its last area forecast discussion before the first event at Jan 5, 2:18 PM MST, 6 hours 42 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
15 extreme cold/wind chill. Local standard time, as filed.
Frigid temperatures occurred in Yellowstone Park. Some of the low temperatures included minus 41 degrees at the Lamar Ranger Station and -35 degrees at the northeast entrance to Yellowstone Park.
The temperature dropped to minus 30 degrees at Greybull.
A weather station 9 miles northeast of Thermopolis recorded a low temperatures of minus 33 degrees.
The COOP observer at Kaycee recorded a low temperature of minus 30 degrees.
Frigid temperatures occurred throughout the Jackson Valley. Some of the coldest lows included minus 36 degrees at the Jackson Hole Airport and minus 32 degrees at Moose.
Brutally cold temperatures occurred on the morning of January 6th. Some of the coldest lows included minus 38 degrees, two miles south of Riverton, minus 33 degrees at the COOP observer and minus 32 degrees at Hudson.
A trained spotter reported a low temperature of minus 31 degrees at Lander.
The COOP observer reported a low temperature of minus 33 degrees at Jeffrey City.
A weather sensor at Independence Rock recorded a low temperature of minus 41 degrees.
Very cold temperatures occurred through the Star Valley. Among the coldest temperatures recorded was minus 35 degrees at the Afton airport.
Frigid temperatures occurred throughout the region. Some of the coldest temperatures included minus 44 degrees at Bondurant and minus 36 degrees at the Pinedale airport.
Extreme cold occurred through the Upper Green River Basin, including minus 32 degrees at the Farson COOP.
Frigid temperatures were common across Southern Lincoln County. Some of the lowest temperatures included minus 40 degrees south of Cokeville and minus 32 degrees at Kemmerer.
Temperatures of minus 30 or below were commonplace across the region, including minus 35 degrees, three miles northwest of Rock Springs.
Frigid temperatures occurred across the region. Three locations east of Rock Springs experienced low temperatures of minus 40 degrees or below, including minus 45 degrees at a site 8 miles East of Rock Springs.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2017Every state in 2017This day in weather historyWarnings in Wyoming, January 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 669758, 669759, 669760, 669761, 669762, 669763, 669764, 669765, 669766, 669767, 669768, 669769, 669770, 669771, 669772.