Light snow will taper off in the Denver area through the morning, with a forecasted high of only 4 degrees.
Passenger vehicles on I-70 between Golden and Idaho Springs are required to have at least an eighth of an inch of tread on their tires or chains.
A winter storm has brought blowing snow, poor visibility and icy roads to the high country.
The regular temperature was just 0 in Denver at dawn on Wednesday but it felt more like 19 below.
The heaviest snow is expected in the northern and central mountains early Monday afternoon, according to the National Weather Service.
The September hailstorm was the eighth-most-expensive ever in Colorado.