Wildfires in the winter: A common sight. Here’s why

A wildfire burns through a development Thursday, Dec. 30, 2021, in Superior, Colo.

David Zalubowski, Associated Press

Strong winds led two wildfires to erupt in Northern Colorado on Thursday afternoon, destroying 600 homes and forcing thousands to evacuate, per The Guardian.

• “This is the kind of fire we can’t fight head on,” Boulder County Sheriff Joe Pelle said, per the report. “We actually had deputy sheriffs and firefighters in areas that had to pull out because they just got overrun.”

Wildfires in winter have become a new normal.

• “Wildfire season has become longer based on conditions that allow fires to start and to burn— winter snows are melting earlier and rain is coming later in the fall. What was once a four-month fire season now lasts six to eight months,” said the Department of Agriculture.
• Other contributing factors are drought, tree mortality from invasive species and aggressive fire suppression which make these longer-lasting fires harder to control.

How can there be fires in the snow?

Burning timber slash in the fall is a common forestry management practice, per Frontline Wildfire Defense.

If an area doesn’t get rain in the fall and the first snow of the year is dry snow, meaning that the surface air temperature is below freezing. Here, the controlled burns can still spread under the snow because the tree litter buried under the snow is still dry enough to burn.

Additionally, dry snow has enough air to fuel fire, but not enough water to quench it. Frontline Wildfire Defense stated that snow does help extinguish fires but there are situations where it can make it worse. The organization advises being careful with controlled fires, even in the winters.

Those who live in fire-prone areas must create defensible spaces, structural hardening and family plans for evacuation to stay safe, per the Department of Agriculture.