(NewsNation Now) — Widespread dangerous heat is in the forecast for several cities across the west, including Los Angeles, Sacramento, Phoenix, Las Vegas and Denver.
Excessive Heat Warnings and Heat Advisories have been issued through Labor Day Monday for much of California and Arizona.
Sacramento, California is expected to reach 111 degrees on Sunday. That would not only be a daily high temperature record, but the hottest temperature in recorded history in the month of September in Sacramento.
Record heat is also expected Saturday and Sunday for Los Angeles, San Diego and Las Vegas through Labor Day.
Denver is expecting record heat Saturday and Sunday with highs in the upper 90s, ahead of major changes early next week with temperatures tumbling to the 20s by Tuesday night with a chance of a rain and snow mix.
The reason for the dramatic change in the weather pattern is a dip in the jet stream that will bring in the first cold blast of the season for parts of the Rockies, Plains and Midwest.
Accumulating snowfall is possible, especially for the highest elevations, for parts of the Rockies and Front Range early next week.