National Weather Service United States Department of Commerce
The April 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

April started off with quite a bang. A strong cold front on the 2nd and 3rd brought widespread snow and temperatures 20 to 30 degrees below normal across the Cowboy State. The 3rd was also quite a popular day for the lowest daily temperature for the month. Four locations actually set new all-time record lows for the entire month of April; Casper, Greybull, Riverton and Worland. The month was so much on the cold side that on the 12th and 13th locations set new daily records for the coldest High temperature. This included Casper, Lander and Worland, all of which have records that date back quite a ways. April did decide to end on a warm tone, with the 29th and 30th the favorites for warmest day. High temperatures were above normal during those last few days and some new daily records were set. Precipitation averages across the climate locations were a mix of above and below normal values. There were a few daily records broken throughout the month. You can read about them in the CLMs linked above. Snowfall for the month was above normal at the 3 locations that report snow. The town of Riverton is not included as a monthly climate site for this program, however it did have its 7th snowiest April on record since 1907. The Riverton airport reported the 5th snowiest April since records started in 1999.

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.