“zombie fires” are rewriting the rules of wildfire season in the arctic

A new type of wildfire is haunting Canada’s northern forests—one that refuses to die even in the depths of winter. These “zombie fires” smolder beneath the snow for months before rising from the permafrost to burn again, fundamentally changing how we understand wildfire seasons in a warming world.

The phenomenon became starkly clear in May 2023 when lightning ignited the Donnie Creek forest in British Columbia. What started as an early-season blaze quickly exploded across the drought-stressed landscape, consuming boreal forest covering an area nearly twice the size of central London. But unlike typical wildfires that end with winter’s arrival, this fire had other plans.

As snow blanketed the region, the flames didn’t extinguish—they went underground. Protected by an insulating layer of snow, the fire continued smoldering in the carbon-rich soil and permafrost throughout the frigid months. When spring returned, so did the fire, erupting from below like something from a horror movie. The zombie fire burned for another full season until August 2024, ultimately destroying over 600,000 hectares (1.5 million acres).

This terrifying new reality reflects a broader crisis unfolding across the Arctic. As climate change warms northern regions and alters precipitation patterns, these overwinter fires are becoming more common, extending fire seasons indefinitely and preventing forests from recovering between burn cycles. The implications are profound: what was once a predictable seasonal threat has become a year-round menace that could fundamentally reshape Arctic ecosystems.