While Sunday will be a warm day with sunshine and a few clouds across Denver and northeastern Colorado, highs on Monday plunge some 20 degrees colder.
The cold will arrive Sunday night with a sharp cold front. Temperatures will nosedive 30-40 degrees in some areas as lows bottom out in the 20s.
Clouds will keep highs in the upper 30s and low 40s across the region Monday, but a gusty easterly breeze will keep it feeling even colder.
Temperatures will skyrocket again for the day on Tuesday and much of the rest of the week with sunshine and highs near 60.
Be sure to keep your immune system up by dressing appropriately early this week, especially if you are susceptible to getting sick during wild temperature swings.
The 2014 Open Championship begins Thursday, July 17 and lasts through Sunday July 20 at Royal Liverpool Golf Club in Hoylake, England.
Friday night saw two breathtaking phenomoma light up the sky, Manhattanhenge and the Supermoon.
Another visit from the Polar Vortex will deliver unseasonably cool air to the Midwest, preceded by rounds of thunderstorms, including severe weather.
A cooldown is on the way for the Minneapolis area headed into the new week.
Heat-related dangers will be on the rise over the weekend for much of the Northwest as scorching heat settles in.
Starting on Sunday, the Northeast and mid-Atlantic will be faced with severe thunderstorms and flooding downpours on multiple days before the new week ends on a more refreshing note.
Pinellas Co., FL (1992)
A tornado blew a catamaran into a car, injuring six people.
Eastern North Carolina (1842)
Hurricane struck, "the worst in 80 years"; vessels ashore on beaches; village of Portsmouth washed away.
Basin, WY (1900)
114 degrees -- hottest ever for Wyoming.