Hold On! Denver Weather Set To Go From Record Heat To Possible Record Cold

DENVER (CBS4) - The first snow to accumulate in September in 20 years is expected Tuesday in Denver. Until then, record heat is expected Saturday and Sunday and it will be among the hottest Labor Day weekend's on record in Colorado. Temperatures will reach the lower 90s along the Front Range on Friday which will be the 70th day in 2020 with a high temperature of at least 90 degrees. The record is 73 days from 2012 which will likely be tied on Monday.

Meanwhile, the current record high for Saturday (Sept. 5) is 98 degrees from 2019 and that record should be at least tied. A few locations on the Eastern Plains will be even hotter with 100 degrees possible.

Sunday should be the hottest day of the holiday weekend with high temperatures near 100 degrees in Denver. The record for Sept. 6 is 97 from 2013 and that record is almost guaranteed to be broken.

Labor Day on Monday will also be warm but temperatures will move away from records with highs in the lower 90s similar to Friday.

Then one of the most shocking changes in Colorado's weather history will happen Monday night. Temperatures will drop about 60 degrees from Monday afternoon to Tuesday morning as a vigorous storm races into the Rocky Mountain region.  Snow will blanket the foothills and mountains and snow is also likely to be falling along the entire Front Range urban corridor by midday Tuesday.

The snow will be heavy and wet and could cause downed trees and power outages in at least some areas.

It would not be the earliest snow on record in Denver but it could tie with Sept. 8, 1962 for the second earliest. And it could be the biggest first snow of the season ever recorded in terms of accumulation.

Looking at Denver's weather history back to 1882, snow in September is not unusual but it has become scarce in recent decades. The last measurable snow in Denver in September was 20 years ago on Sept 24, 2000.

The month averages about 1.3" inches with snow occurring once about every 5 years. There have been some very large snow storms in September but they have all occurred much later than September 8. In September 1971 there was 17.2 inches of snow in Denver, in 1936 there was 16.5 inches and in 1959 the city measured 12.9 inches of snow in September.