Isahultila Fire

2015192,663 acresAlaska

The Isahultila Fire burned 192,663 acres, about 301 square miles, across Yukon-Koyukuk Census Area. It began on June 22, 2015.

Watch how it happened

Isahultila Fire · 2015

How it happened

Watch it burn in the order satellites saw it, coloured by how severely each place burned.

About this replay

Date (UTC)—Historical replay

Burned so far—acres

High severity—of the area so far

Detections6,906satellite fire pixels

Fire milestones

Burn severityHigh, Moderate, Low, Unburned to low, Increased greenness

Burning nowAreas reached in the last half day of satellite passes

Chicago, to scale228 square miles of land, drawn at the fire’s scale

Timing: NASA FIRMS satellite fire detections (5,557 VIIRS and 1,349 MODIS) inside the final perimeter; each place takes the time of its nearest detection, so the order is satellite-observed but interpolated between passes, roughly every 12 hours. Severity: Monitoring Trends in Burn Severity (USGS, U.S. Forest Service), mapped from Landsat after the fire.

How severely it burned

Burn severity inside the final perimeter, classified from Landsat images taken before and after the fire.

Map of burn severity across the Isahultila Fire

Burn severity by class
Severity	Share	Acres
Highmost vegetation consumed, soils altered	24%	46,138
Moderatemixed: many trees killed, some survive	31%	59,087
Lowsurface fire, most trees survive	20%	38,253
Unburned to lowislands inside the perimeter, little change	13%	25,367
Not mappedcloud, shadow or water in the satellite images	12%	23,767

24% of the area inside the perimeter burned at high severity, about 46,138 acres; 55% burned at moderate or high severity.

Monitoring Trends in Burn Severity (U.S. Geological Survey and USDA Forest Service). Classes come from the change in a Landsat burn index (dNBR) between images before and after the fire; acres are each class’s share of the fire’s mapped area.

Where it burned

Acres inside each county, measured from the satellite-mapped perimeter.

Acres burned by county

Yukon-Koyukuk Census Area	AK	192,796

Other large fires in Alaska in 2015

Middle Yukon Fires407,220 acres
Tobatokh Fire220,037 acres
Holtnakatna Fire180,199 acres
Tanana Area Fires176,773 acres
Rock Fire142,933 acres
Big Mud River 1 Fire140,914 acres
Munsatli 2 Fire124,572 acres
Blazo Fire123,916 acres

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.