DENVER, Colo. – Streetlights flicker through a frosty haze this morning as the Mile High City braces for its coldest air of the season. The National Weather Service has issued a Freeze Warning for much of the Front Range — including Denver, Boulder, Fort Collins, and Aurora — where temperatures will tumble into the lower 20s tonight.
According to the NWS Denver/Boulder office, the freeze takes effect from 10 p.m. this evening through 10 a.m. Wednesday, with lows between 19°F and 25°F expected across the I-25 corridor. The agency warns that the cold will end the growing season for many areas and could damage outdoor plumbing or unprotected irrigation systems. Residents are urged to cover or bring in potted plants, drain sprinkler lines, and let faucets drip lightly to prevent frozen pipes.
Some locations north and east of Denver — including Weld and Larimer Counties — have already recorded a “killing freeze,” but urban neighborhoods remain vulnerable. Patchy frost will likely blanket rooftops and lawns by sunrise Wednesday, marking a definitive turn toward late fall.
The chill eases quickly by Thursday as high pressure rebuilds across the Plains, pushing daytime highs back into the upper 50s and lower 60s by Friday. Halloween looks seasonably mild for trick-or-treaters, with clear skies, light winds, and evening readings in the upper 40s.
Beyond the weekend, early November trends point drier but breezy — typical for Colorado’s winter transition.
And don’t forget — clocks “fall back” early Sunday morning as Daylight Saving Time ends. A chilly November lies ahead.
Five-Day Forecast for Denver, CO:
Wed: 47/26 – Clear and cold early; sunny rebound by afternoon.
Thu: 56/30 – Mostly sunny; lighter winds, milder afternoon.
Fri: 60/34 – Pleasant and dry; great for Halloween evening.
Sat: 62/36 – Sunny and calm; crisp morning start.
Sun: 64/38 – Mild and bright; clocks fall back early Sunday.
