National Weather Service Riverton WY 418 PM MDT Sun Sep 19 2021 ...FREEZE WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING... Upper Wind River Basin-Wind River Basin-Lander Foothills- Green Mountains and Rattlesnake Range-Star Valley- Upper Green River Basin Foothills-Upper Green River Basin- South Lincoln County-Rock Springs and Green River-Flaming Gorge- East Sweetwater County- Including the cities of Dubois, Riverton, Shoshoni, Lander, Jeffrey City, Afton, Alpine, Star Valley Ranch, Thayne, Pinedale, La Barge, Big Piney, Farson, Kemmerer, Cokeville, Rock Springs, Green River, and Wamsutter 418 PM MDT Sun Sep 19 2021 * WHAT...Low temperatures 27 to 31, with 21 to 26 in the far west valleys and basins. * WHERE...Most lower elevation locations in Fremont, Sweetwater, Sublette, and Lincoln counties. * WHEN...Late Monday night and Tuesday morning. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing. * ADDITIONAL DETAILS...The coldest temperatures will occur in the lower elevations of Sublette and Lincoln counties where a hard freeze across a wide area is possible. In Fremont and Sublette counties, locations near rivers and creeks will be coldest with possible overnight lows around 30. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. To prevent freezing and possible bursting of outdoor water pipes they should be wrapped, drained, or allowed to drip slowly.