From California to Idaho: America's top wildfire risk states

Wildfire in the U.S. has stopped behaving like a season. One of Colorado's most destructive fires on record ignited on Dec. 30, two days before New Year's Day. Texas set its all-time acreage record in late February. California's worst wind-driven fires have hit in October, November, and January — months once treated as the far edge of the calendar. The states most at risk of wildfires are no longer defined by a summer window or by mountain timber alone.

Federal and state agencies, including the National Interagency Fire Center, gauge danger through a handful of measurable inputs: how much dry vegetation is available to burn, how far relative humidity falls, how hard and how steadily the wind blows, and how close houses sit to untreated wildland. That last variable, the wildland-urban interface, has grown faster than almost any other. Population growth in the West pushed subdivisions into canyon mouths, foothills, and rangeland that burned on a natural cycle long before anyone built there.

The highest-risk states share three conditions. They hold large, continuous stretches of dry forest, brush, or grass. Their fire seasons run longer than they did a generation ago, partly because snowpack melts earlier and autumn rains arrive later. They have also added homes, power lines, and roads to landscapes where fire is a routine ecological event rather than an anomaly.

The differences between them matter. A fire in the Texas Panhandle runs through cured grass at highway speed across flat ground. A fire in central Idaho can smolder for days in roadless wilderness before weather drives it into a run. A fire on the outskirts of Tucson burns through buffelgrass, an African import planted across the Southwest for cattle forage and erosion control. Each demands different equipment, different building codes, and different insurance math.

The 10 states below combine fuel, climate, and development in ways that produce the greatest exposure in the country. Each entry covers the terrain that carries fire there, the fires that defined the modern record, and the regional conditions that keep the risk high.

Illustration: Quartz

California faces the highest combined wildfire risk of any U.S. state. Its size, dry Mediterranean climate and millions of homes built against unmanaged wildland all compound one another. The 2018 Camp Fire, which destroyed most of Paradise in Butte County, remains the deadliest and most destructive fire in state history.

The underlying pattern is a long rainless stretch from late spring into autumn, followed by offshore winds that arrive while vegetation sits at its driest. Southern California gets the Santa Ana winds. The Bay Area and northern coast ranges get the Diablo winds. Both blow from the interior toward the coast, warming and drying as they descend, and both can push flames through chaparral faster than crews can cut containment line.

Terrain compounds the problem. Steep canyons funnel wind and let fire run uphill at speed. In the Sierra Nevada, more than a century of aggressive suppression left forests denser than they were historically, with ladder fuels that carry flame from the ground into the canopy.

Timing has shifted too. The January 2025 Palisades and Eaton fires burned through Los Angeles County neighborhoods during what was once reliably the wet season, after an exceptionally dry start to winter.

Development converts fire danger into disaster. California has a very large population living in the wildland-urban interface. Subdivisions, single access roads and power lines sit inside landscapes that burned on a natural cycle long before anyone built there. Wind-carried embers, not advancing flame fronts, destroy most of the houses lost in these events.

The financial consequences now reach homeowners who never see flames. Several major insurers have pulled back from writing new policies in parts of the state, pushing more properties onto the California FAIR Plan.

The state's response runs on several tracks at once. Cal Fire requires 100 feet of defensible space around structures in designated hazard zones. Chapter 7A of the state building code mandates ignition-resistant roofing, siding, vents and windows for new construction in high-risk areas. Utilities shut off power preemptively during extreme wind warnings. Prescribed burning and forest thinning programs have expanded, though the treated acreage remains a small fraction of the land carrying heavy fuel loads.

Illustration: Quartz

Texas burns mostly grass and brush rather than timber, and those fuels ignite and run faster than forest fuels do. That mix, spread across the second-largest state, produced the Smokehouse Creek Fire of 2024 — the largest wildfire in Texas history.

Smokehouse Creek started in the Panhandle in late February 2024 and burned more than a million acres of ranchland before crossing into Oklahoma. Thousands of cattle died. Homes were lost across Hutchinson and Roberts counties. Xcel Energy $XEL said its facilities appeared to have been involved in igniting the fire.

The state is large enough to hold several fire regimes at once. The Panhandle and Rolling Plains run to cured native grass on open ground with few natural breaks. The Edwards Plateau carries thick stands of ashe juniper, whose oily foliage torches on contact. East Texas sits in the southern pine belt, where the 2011 Bastrop County Complex Fire swept through the Lost Pines and destroyed roughly 1,600 homes, the most destructive fire in state history by structures lost.

Timing separates Texas from most other high-risk states. The dangerous stretch opens in winter and peaks in late winter and early spring, before grasses green up. Dormant vegetation is already cured, and passing cold fronts bring the low humidity and sustained wind that turn a roadside spark into a running fire within minutes. A dry La Niña winter sharpens that setup across the southern plains.

Response capacity is a separate problem. The Texas A&M Forest Service coordinates statewide, but first response in rural counties falls largely to volunteer departments running older brush trucks with long drives between water sources.

Ranch country also has little zoning. Houses, barns, and stored hay sit in continuous fuel with no cleared buffer, and one fire can take out the fencing, water wells, and winter feed a ranch needs to keep livestock alive after the flames pass. Grazed pasture, county roads, and plowed fence lines often serve as the only breaks available.

Illustration: Quartz

Colorado's wildfire risk is concentrated along the Front Range, where fast-growing suburbs sit directly against grass-covered foothills and beetle-damaged mountain forest. The Marshall Fire of Dec. 30, 2021, destroyed more than 1,000 homes and structures in Superior, Louisville and unincorporated Boulder County, making it the most destructive fire in state history by property loss.

The fuel is what set that fire apart. It ran through dry grass rather than timber, driven by downslope winds gusting past 100 mph across ground with almost no snow on it in late December. Colorado's foothill grasslands cure out and turn receptive to fire whenever a dry stretch lines up with strong wind, and that combination can occur in any month.

The forested side of the risk looks nothing like it. A mountain pine beetle outbreak that peaked in the 2000s killed lodgepole pine across millions of acres in Colorado and southern Wyoming, leaving standing dead trunks and downed timber behind. Decades of fire suppression thickened the understory beneath them, so large sections of the high country now hold far more burnable material than they did historically.

The 2020 season showed what those conditions can produce. The Cameron Peak Fire west of Fort Collins became the largest wildfire on record in Colorado, and the East Troublesome Fire crossed the Continental Divide in a single night, pushing into the Grand Lake area and the edge of Rocky Mountain National Park.

Terrain magnifies both problems. A fire that starts in lower grassland can climb into timbered slopes above it, and canyons around Boulder and Colorado Springs funnel wind in ways that make the direction of spread hard to forecast hour to hour.

Development remains the variable changing fastest. The corridor running from Fort Collins through Denver to Colorado Springs keeps adding housing in the wildland-urban interface, much of it on ground with a documented history of burning.

Earlier snowmelt and warmer, drier autumns have widened the window further. A fire that leveled two suburbs two days before New Year's left Colorado without a dependable off-season.

Illustration: Quartz

Oregon's wildfire exposure comes from two landscapes that burn in entirely different ways: the dense conifer forests of the Cascades and the open sagebrush and juniper country east of them. Both have produced fires measured in hundreds of thousands of acres, and the state's worst seasons tend to involve both at once.

The Labor Day fires of 2020 remain the clearest illustration. Dry east winds funneled through gaps in the Cascade crest on Sept. 7, pushing several fires down the west slope into populated valleys overnight. The town of Detroit was largely destroyed. In the Rogue Valley, the Almeda Drive Fire burned through neighborhoods in Talent and Phoenix. More than a million acres burned across the state that year.

East of the crest, fire works on a different scale. The Bootleg Fire in Klamath County burned more than 400,000 acres in July 2021 and grew large enough to generate its own weather, including pyrocumulus clouds that disrupted aerial operations. Farther southeast, in Harney and Malheur counties, sagebrush steppe fires cross enormous distances over terrain with almost no roads, no hydrants and few residents.

Western juniper has spread across much of eastern Oregon's rangeland over the past century, adding resinous, high-volatility fuel to country that once carried mostly grass and low shrubs. Ranchers in those counties run Rangeland Fire Protection Associations, volunteer organizations recognized by the state, and they often reach a fire hours before an agency engine arrives.

Smoke is the state's most widely felt wildfire effect. During the September 2020 fires, Portland registered some of the worst air quality readings in the world, and smoke from Oregon blazes regularly degrades air across Washington state, Idaho and southern British Columbia.

Much of Oregon's forestland sits under federal management, which shapes how thinning and prescribed burning get funded and scheduled. The Oregon Department of Forestry handles protection on most private and state-owned forest, so a single large fire often crosses jurisdictions and pulls in federal, state and local crews at once. Treatment work still covers far fewer acres each year than the state's overstocked stands contain, and heavy suppression spending during bad seasons competes for the same dollars.

Illustration: Quartz

Arizona runs fire danger across a wider elevation range than almost any other state, from Sonoran Desert floor below 1,000 feet to ponderosa pine forest above 6,000. That vertical spread means something in the state is usually dry enough to burn, and fire activity rarely stays inside one stretch of the calendar.

Invasive grasses have changed how the low desert burns. Buffelgrass and red brome, neither one native to North America, fill the bare ground between saguaro, palo verde and creosote that once kept flames from carrying. Sonoran Desert plants did not evolve with regular fire and mostly do not survive it. Saguaros die outright. The grasses grow back fast, which pushes the landscape toward repeat burning that converts desert into grassland.

The high country carries a separate problem. Northern Arizona holds one of the largest continuous ponderosa pine forests in North America, running along the Mogollon Rim through the Coconino, Kaibab and Apache-Sitgreaves national forests. A century of suppression let dense young trees crowd stands that once burned at low intensity every few years. The 2002 Rodeo-Chediski Fire moved through that terrain and set a state acreage record, and the 2011 Wallow Fire broke it. Wallow remains the largest wildfire in Arizona history.

Timing follows the monsoon. The driest, windiest stretch of the Arizona year typically falls from April into June, before seasonal moisture arrives. Dry lightning at the leading edge of the monsoon can start fires while the rain behind it is still too light to put them out. Once storms do arrive in force, burned slopes stripped of vegetation turn into flash flood channels, so the hazard shifts from fire to water within weeks.

Development has closed the distance between people and fuel. Growth around Phoenix, Tucson, Prescott and Flagstaff has pushed subdivisions into desert foothills and pine forest alike, placing homes in the wildland-urban interface across several ecosystems at once. Fire agencies in the state have to plan for desert grass runs and crown fires in timber inside the same operational season.

Illustration: Quartz

Washington state's wildfire risk divides along the Cascade crest. The range blocks Pacific moisture, leaving the eastern two-thirds of the state dry enough to support shrub-steppe, wheat country, and open ponderosa pine — the fuels behind nearly every one of the state's largest fires.

The 2014 Carlton Complex burned roughly 250,000 acres in Okanogan County, destroyed homes around Pateros and the Methow Valley, and remains the largest single wildfire recorded in the state. The following summer, the Okanogan Complex burned a larger total area, though as a group of separate fires rather than one.

Eastern Washington's dominant fuel is grass, not timber. Bunchgrass and sagebrush dry out by midsummer and carry fire across rolling, largely unirrigated ground. Downslope winds off the Cascades can push those runs across tens of thousands of acres in an afternoon, far ahead of engine crews limited to gravel county roads.

Labor Day 2020 showed the community-scale version. An east wind event drove the Babb Road Fire into Malden, in Whitman County, and most of the town's structures were gone within hours. Several other fires made major runs the same day across central and southeastern Washington.

Western Washington burns too, on a different timeline. The 2015 Paradise Fire smoldered for months in the Queets rainforest inside Olympic National Park, one of the wettest places in the lower 48 states. Warmer, drier Augusts and thinner mountain snowpack have made late-summer ignition west of the crest more plausible than it was a generation ago.

Timber is a working industry on both sides of the mountains, which puts managed forestland, mill towns, and recreation communities inside the same fuel beds that carry fire. The Washington Department of Natural Resources has expanded its aviation fleet and added year-round firefighting capacity, matching a fire calendar that now opens in June and holds through October.

Illustration: Quartz

New Mexico's largest wildfire on record, the 2022 Hermits Peak-Calf Canyon Fire, grew out of two U.S. Forest Service prescribed burns that escaped containment in Mora and San Miguel counties and merged into a single blaze across more than 340,000 acres. Congress later created a federal compensation fund for residents who lost homes, grazing land and livelihoods.

The fire exposed what sits underneath the state's risk: forests holding far more fuel than they evolved to carry, dried by one of the longest drought runs the Southwest has recorded. Ponderosa pine stands in the Sangre de Cristo and Jemez mountains once burned at low intensity every few years, thinning seedlings and clearing litter. A century of suppression packed those gaps with dense young growth, building a ladder that carries flame from the ground into the crowns. Fire then travels through connected canopy rather than along the forest floor.

Bark beetle outbreaks have added standing dead timber to the load. Drought in the early 2000s killed broad tracts of piñon pine across the state's lower woodlands, leaving brittle fuel on slopes that drain toward populated canyons.

Timing compounds all of it. The windiest stretch of the New Mexico calendar falls in April and May, weeks ahead of the monsoon moisture that reaches the state in early summer. Relative humidity can drop into the single digits while sustained winds blow for days. Hermits Peak-Calf Canyon ignited in April and did most of its damage before July. The 2011 Las Conchas Fire, which burned near Los Alamos and into Bandelier National Monument, started in late June, still ahead of the rains.

Response capacity is thinnest in the places most exposed. Villages across northern New Mexico sit at the end of narrow mountain roads, depend on volunteer fire departments and draw water from acequias and wells instead of pressurized hydrants.

Burn scars then create a second hazard. Stripped slopes push ash and debris into the same valleys once monsoon storms arrive, a sequence that damaged property and fouled the Gallinas River, the drinking water source for Las Vegas, New Mexico, after the 2022 fire.

Illustration: Quartz

Idaho's defining wildfire problem is access. Much of the state's burnable timber sits inside roadless backcountry with no way to drive an engine to a fire line. Ignitions in the central mountains can grow for days before crews reach them on the ground.

The Frank Church–River of No Return Wilderness covers roughly 2.3 million acres of canyon and timber, and it is the largest contiguous federally designated wilderness in the lower 48 states. With the adjoining Selway-Bitterroot Wilderness, it forms a block of country where suppression depends on smokejumpers, helicopter crews and aerial retardant instead of engines and dozers. Fires there are often managed rather than attacked outright, with crews holding the edges near structures and trailheads while the interior burns.

Lightning starts a large share of those backcountry fires. Summer thunderstorms cross the Salmon River and Clearwater drainages and deliver strikes with little rain behind them. A fire can sit at a few acres in heavy timber for weeks, then make a long run once the wind shifts or the fuels dry out.

Southern Idaho carries the opposite landscape and a separate hazard. Across the Snake River Plain and the Owyhee country, cheatgrass has displaced native sagebrush understory over huge stretches of rangeland. The invasive annual cures by early summer and knits patchy desert into continuous fuel, letting fire move over open ground at speed. Each burn clears more sagebrush and favors more cheatgrass, which shortens the interval between fires and erodes habitat that greater sage grouse and pronghorn depend on.

Development concentrates the human exposure. The Boise foothills and the Wood River Valley near Ketchum have added homes along the seam between subdivision and brush-covered slope — terrain that funnels fire uphill toward whatever sits above it.

Smoke is the state's most widely felt export in an active season. Valley inversions trap haze over Boise, McCall and the Clearwater basin for days at a time, and plumes off the central mountains degrade air quality across the Northern Rockies and out onto the plains.

Illustration: Quartz

Montana carries two separate wildfire problems at once: dense, beetle-damaged timber across its western mountains and open rangeland covering the eastern two-thirds of the state. The 2017 season burned more than a million acres statewide and prompted a fire emergency declaration, a year that remains the reference point for how severe conditions there can get.

Western Montana's forests occupy rugged, lightly roaded country in the Bitterroot, Flathead and Lolo drainages. Bark beetle outbreaks have killed broad stands of lodgepole pine and other conifers across the Northern Rockies, leaving standing dead trees and heavy surface fuel. A fire in that terrain can grow for hours before engines and hand crews arrive, so initial attack often depends on air tankers and the smokejumpers based at Missoula.

East of the mountains the fuel changes entirely. Grass and sagebrush rangeland running toward the Dakotas burns fast and wide in drought years, and the open country offers few natural breaks. These fires hit cattle operations directly, taking pasture, hay stores and fence line across ranches measured in thousands of acres. Replacing miles of burned fence is a cost that lingers long after a fire is out, and lost grazing forces ranchers to cut herd numbers or buy feed.

Montana's burning window has stretched. Heavy fire activity now runs from June into September, pushed by snowpack that melts earlier and leaves soil and vegetation dry weeks ahead of past norms. A dry August following a hot July cures forest and grassland at the same time, which pulls state firefighting resources in two directions at once, from Missoula to Miles City.

Smoke is the statewide consequence. Valley towns such as Missoula and Helena sit in terrain that traps smoke beneath temperature inversions, holding unhealthy air in place for days. In heavy seasons, plumes from Montana fires drift east across the plains and into the upper Midwest, carrying the effects of the state's fire conditions well beyond its borders.