Wyoming’s dry high desert air felt crisp early, but the heat built fast across Riverton by late morning as bright sunshine reflected off open fields and foothill terrain. Temperatures climbed steadily toward the low 80s, signaling the start of a much warmer stretch for central Wyoming.
According to the National Weather Service, Riverton is expected to reach 85 degrees by Memorial Day afternoon under mostly sunny skies. Light southwest winds strengthen later in the day, with occasional gusts topping 20 mph. Isolated thunderstorms remain possible near the Wind River Mountains and surrounding higher terrain through the afternoon hours.
The warmup stretches across much of Wyoming as broad western high pressure keeps conditions mainly dry through early Tuesday. Casper, Lander, and Thermopolis should also see highs climbing into the 80s, creating ideal travel weather along U.S. 26 and Wyoming Highway 789.
By Tuesday afternoon, the weather pattern starts shifting. Increasing moisture and stronger southwest winds could spark scattered thunderstorms across central Wyoming. Some storms may produce brief heavy rain, small hail, and wind gusts approaching 28 mph, especially west of Riverton and along mountain corridors.
Wednesday turns more unsettled statewide. Showers and thunderstorms become more widespread as cooler Pacific energy moves into the northern Rockies. Temperatures remain warm near 80 degrees, but changing skies and breezy conditions may impact outdoor holiday travel and recreation plans.
Long-range outlooks suggest temperatures could remain slightly above average heading into early June, though periodic Rocky Mountain storm systems may keep afternoon thunderstorm chances active across Wyoming through late next week.
Five Day Forecast for Riverton, Wyoming:
- Monday: Sunny and warm, high near 85°F
- Tuesday: Mostly sunny with slight thunderstorm chances, high near 84°F
- Wednesday: Chance of showers and thunderstorms, high near 80°F
- Thursday: Mostly sunny with isolated storms possible, high near 81°F
- Friday: Sunny and breezy, high near 81°F
