An early snowfall struck the Rocky Mountains on September 8-9, 2020, dropping both temperatures and snow across the region. The Weather Channel reports that at least nine locations experienced their earliest snowfall on record. These were: Casper and Cheyenne, Wyoming; Rapid City, South Dakota, Fort Collins, Yuma, and Pueblo, Colorado; North Platte, Nebraska; Goodland Kansas; and Las Vegas, New Mexico.
As snow fell, so did the temperatures. Many states had been sweltering under a heat wave through August. Denver, Colorado reported at least 73 days of 90˚F (32.2˚C} in a row by September 6 and an all-time record high of 101˚F (38.3˚C) on September 5. Fort Collins, Colorado, reported a high of 99˚F (37.2˚C) on September, but by September 8, that town was shivering with a high of 41˚F (5˚C) and had 2 inches of snow to clear. Denver’s temperature had also plunged to a high of 41˚F (5˚C) and had 1 inch (2.5 cm) accumulation.
On September 8, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of snow across the Rocky Mountains. The image has captured parts of Idaho (west), Montana (north), and Wyoming (southeast).