The National Weather Service reports that Lander tied for the driest month this past May since 1891. Only .06 inches of precipitation fell during May, which was 2.14 inches below normal. Additionally Lander’s average temperature during May was 55.6 degrees, 0.8 degrees warmer than average. It was the 14th warmer May on record.
For Riverton, the airport received 0.32 inches of precipitation for the the month, the third driest May there, while the average temperature of 54.5 degrees was the 12th warmest on record since 1996. Downtown Riverton recorded 0.34 inches of precipitation in May, which was 1.11 inches below normal for the ninth lowest on record. The average temperature of 56.2 degrees was the 24th warmest since 1907.
See the graphic below for Western Wyoming highs and lows: