Arctic air is here at least through the week By: Erin Yost - MTN News Posted at 4:33 PM, Feb 09, 2021 and last updated 2021-02-09 20:12:18-05 High pressure will continue to build in from the north allowing a bitterly cold airmass to move into the region. And that's the big weather story moving ahead! Skies will remain mostly cloudy with random flurries at times. Highs will struggle to make it above 0° the next few days for most of the viewing area... this will likely make it into the 'top 10' for longest stretches below 0° in recorded history for Great Falls. Overnight lows? Well, it's best you know that it'll just be downright frigid, but here are the specifics for Great Falls and Helena respectively: