This summer, record rainfall fell at the Riverton Airport – 318% of normal – according to the National Weather Service. With 5.59 inches total from June through August, it’s the wettest summer on record since the last record summer rain total in 1997. In Lander, 5.06 inches of rain were recorded, making it the eighth-wettest summer recorded since the record in 1891.
According to the National Weather Service in Riverton, several factors played a role in the rainy summer months, including Wyoming being in a “mean trough position” for much of the season, which tends to “induce lift in the atmosphere, and therefore clouds and showers. The jet stream was also fairly close to the area this summer, which is the focus of weather disturbances riding across the country, and help to produce thunderstorms … we spent much of the time between upper level lows and highs, and the weakness between these systems is where deeper moisture tends to travel,” they wrote. “This was mainly from the Gulf of Mexico early this summer, and from the normal Monsoonal flow later in the summer. In addition, we have had moisture from decaying tropical storms and hurricanes move over the area a couple of times this year.”