National Weather Service United States Department of Commerce
The May 2020 climate summaries for Big Piney, Buffalo, Casper, Greybull, Lake Yellowstone, Lander, Riverton, Rock Springs, and Worland are now available online.

Big Piney




Lake Yellowstone



Rock Springs


Monthly Summaries

May was a very dry month across western and central Wyoming. Casper and Lander actually tied for the driest May on record, and they have climate records that go quite a ways back. Riverton airport and the town of Riverton were both set to tie for first place as well, but thunderstorms on the 30th and 31st dropped enough rain to knock them out of first. The only precipitation records set in May were at Worland, Buffalo, Riverton and Lake Yellowstone. The temperatures in May were all above normal except for Lake Yellowstone which met their normal temperature of exactly 40 degrees. Every location had some type of temperature record broken in May with the exception of Riverton airport. A majority of the new high temperature records were set on the 29th, 30th and 31st when the Cowboy State had a nice heat wave.

Check the CLMs for more specifics on daily records set at the various locations. See the links above for details for individual sites or click here for Water Year Precipitation summaries for more locations.

If you would like additional, or more in-depth climate information, please refer to our Climate Page. From the Riverton Home Page, hover over the "Climate and Past Weather" tab, and select the "Local" option. You can then find the Daily Climate Report (CLI), the Preliminary Monthly Climate Data (CF6), the Monthly Weather Summary (CLM), and the Regional Summary (RTP). The Daily Climate Report will have the weather data for the day (from midnight to 1159 pm). The Monthly Climate Data (CF6) will have this data for each day of the month, compiling all the daily data into one form. The Regional Summary will have temperature and precipitation data for various locations across the state, updated 3 times a day.