Share of Wildfires Caused by Humans by State 2025

What this chart shows. The share of wildfires listed as human-caused in each state in 2025, for the 34 states with at least 500 fires. Iowa, Kentucky and Missouri reported no lightning fires at all, so their share is 100 per cent; Colorado had the lowest share at 51.5 per cent.

How the data is collected. The NICC annual report places every fire in its state table in one of two cause columns, human or lightning. Nationally, 69,556 of the 77,850 fires were in the human column, 89.3 per cent.

Background. Human-caused fires burned 2,274,333 acres, 44.3 per cent of the land burned nationally, against 2,857,141 acres for lightning fires: lightning started far fewer fires but burned more land. All 9 states below 70 per cent on this chart are in the West.

Limits. The state table has no separate column for fires whose cause is undetermined, even though the same report lists several of its largest fires as undetermined, and it does not say how such fires are assigned. States with fewer than 500 fires are left out because a handful of lightning strikes could swing their share.