This Halloween could deliver a weather trick, or what some snow lovers may consider a treat.

A storm system is likely to impact Colorado on October 31 this year.

It is rare to get snowfall on Halloween in Denver. There has only been measurable snow ten times since 1940.

The biggest Halloween snowstorm was 8 inches back in 1972 -- just before midnight. It went on to snow another 8.8 inches overnight, into November 1.

This year’s storm will bring a stark contrast to the last couple of Denver Halloweens. We tied a record high temperature of 79 degrees last year, and in 2015 we had a mild temperature of 69 degrees.

The average high temperature in Denver on Halloween is 59 degrees.

On average, Denver gets Halloween snow about every 7 years. It hasn’t snowed since 2004, so you could say we are due.

Computer forecast models are showing a trough developing north of Colorado on Monday. The severity of the storm will depend on where the main piece of vorticity sets up, and whether it stacks down to the surface.

Either way, Colorado will likely be impacted. If it’s just a scrape from an upper low, or if it’s a stacked winter storm system.

Expect some of the lowest Halloween temperatures Denver has seen in several years, and expect to see some snow during peak trick-or-treating hours.