New research shows climate change is fundamentally altering when fires ignite across North America.

In California and the arid West, the fire season is stretching deep into late fall and winter.

Northern boreal forests in Alaska and Canada now face earlier snowmelt, leading to spring fires.

Scientists analyzed NASA satellite data from 2001 to 2020 to map these shifting burn patterns.

Unlike the West, North American prairies have seen minimal changes in their seasonal fire timing.

Predicting these shifts is vital for managing the severe health risks posed by wildfire smoke.

High-emission models suggest California's season could extend by more than a full month.

Canada saw its worst wildfire season in 2023, followed by another severe year in 2025.

While climate drives the season, 85% of wildland fires are still caused by human acts.

Understanding regional shifts helps authorities allocate resources for the worst windows of risk.

Source: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL121153