On July 13, 2025, a fire ignited near Willowdale, Oregon, in the remote grasslands of Jefferson County. In the days that followed, it exploded across the region, forcing evacuations, destroying buildings, and blackening the skies. Now spanning more than 95,000 acres, the Cram Fire is on the verge of becoming the first U.S. “megafire” of the year.
But what exactly does that term mean? And is it a helpful label—or a misleading one?
As megafires become more frequent across the globe, scientists are still debating the best way to define and describe them. The outcome of this debate matters—not just to researchers and fire officials, but to anyone living in fire-prone regions or breathing smoke from hundreds of miles away.
The Cram Fire: 2025’s First “Megafire”?
As of July 21, 2025, the Cram Fire in Oregon has scorched over 95,000 acres, making it the largest wildfire in the United States this year.1
First reported on July 13 near U.S. Route 97, the blaze prompted the Governor of Oregon to invoke the Emergency Conflagration Act, allowing state agencies to assist overwhelmed local crews. So far, the fire has:
- Triggered evacuations in multiple zones
- Threatened hundreds of structures
- Required the mobilization of federal and state firefighting teams
If it crosses the 100,000-acre mark, it will officially be considered a megafire under the most common U.S. definition. But even now, its impact is being felt beyond the fire line: smoke from the Cram Fire and surrounding blazes has triggered air quality alerts across the Pacific Northwest.
It’s a sobering reminder that wildfire is not just a local issue, entire regions are often impacted. As these massive fires grow, so do their consequences—for human health, ecosystems, and the global climate.
What Is a “Megafire”?
The term “megafire” is most commonly used to describe wildfires that exceed 100,000 acres in size (roughly 40,000 hectares), especially when they are intense, fast-moving, and destructive.
But there’s no single, universal definition.
In fact, a 2022 study published in Global Ecology and Biogeography found that the term is used inconsistently in scientific literature around the world.2 The researchers reviewed over 100 studies and discovered that “megafire” thresholds ranged anywhere from 10,000 to 100,000 hectares (~25,000 to ~250,000 acres). Most agreed that the term involves extreme size, but some emphasized impacts on people and ecosystems over raw acreage.
To bring clarity, the authors proposed a tiered structure:
- Megafire: >10,000 hectares (≈ 25,000 acres)
- Gigafire: >100,000 hectares (≈ 250,000 acres)
- Terafire: >1,000,000 hectares (≈ 2.5 million acres)
Their aim was to standardize how scientists talk about increasingly large fires in a warming world—and to prepare for a future where even bigger, more destructive fires are possible.
A Firestorm of Disagreement
But not everyone agrees that “megafire” is a useful term at all. In fact, the authors of the 2022 study who proposed a tiered definition for fire size—introducing “megafire,” “gigafire,” and “terafire”—and explicitly encouraged further debate to refine these terms as the world adapts to a new fire reality and that is exactly what happened.
A 2023 paper titled Megafire: A Term to Avoid (Nimmo et al.) followed, arguing that the label is vague, emotionally loaded, and potentially misleading.3 According to these authors, “megafire” implies that fire itself is inherently catastrophic—ignoring the crucial ecological role it plays in many landscapes.
They also warn that the term encourages simplified media narratives that can lead to poor policy decisions, like aggressive fire suppression in ecosystems that actually depend on fire to remain healthy. Not all large fires are bad, they say—and not all small fires are good.
While the authors of this paper took issue with the term itself, they asserted that their response wasn’t meant to dismiss the crisis—it was a call to reframe how we talk about fire. Instead of using “megafire,” they advocate for more precise, descriptive language based on metrics like:
- Fire size
- Fire severity (ecological and human impacts)
- Fire duration
- Type of vegetation affected
Their core message: When it comes to wildfires, context matters more than categories. Or in their precise words: “Redefining megafire to a one-size-fits-all approach limited to fire size does not capture its rich and diverse use and has the risk of creating a disconnect between science.”
Where the Experts Agree
Despite their differing views on terminology, both teams share crucial areas of agreement—areas that should shape public understanding, policy, and preparedness moving forward:
- Wildfires are getting bigger and more destructive, largely due to human activity and climate change.
- Clear communication is essential for public understanding, emergency response, and scientific progress.
- Fire impacts must be evaluated in terms of ecological function, human health, and community vulnerability, not just acreage.
- There’s a pressing need to prepare for a future where extreme fire events are more common.
In other words, whether you call them “megafires” or not, these massive wildfires are becoming more frequent, more intense, and more disruptive to life across the globe. What matters now is that we understand the risks—and respond with clarity, compassion, and science-informed action.
What This Means for All of Us
You don’t have to live in Oregon or California to be affected by megafires. Their smoke can travel thousands of miles, aggravating asthma, heart disease, and other health conditions far beyond the fireline. Their carbon emissions accelerate climate feedback loops, setting the stage for even more frequent and intense fires. And their costs—emotional, financial, and ecological—don’t stop at state lines. They ripple outward across regions, borders, and generations.
We know this isn’t the first time we’ve written about wildfires—and it probably won’t be the last. But we’re not trying to sound like a broken record. We’re just pro-safety, pro-science, and pro-human-health, and we believe this message can’t be shared enough.
With wildfires growing in both size and reach, repetition isn’t redundancy—it’s reinforcement. We want this guidance to feel familiar before you ever need it in an emergency.
Some groups are especially vulnerable to wildfire smoke—including young children, older adults, pregnant people, and anyone with pre-existing health conditions. Children breathe more air per pound of body weight than adults, and their lungs are still developing, making them particularly susceptible to the effects of smoke and air pollution.
So what can you do?
- Stay informed: Follow local air quality alerts and wildfire reports.
- Create a clean air space: Use HEPA and activated carbon filtration (like those in the Austin Air HealthMate Plus) to reduce your exposure to wildfire smoke indoors.
- Support policies that prioritize resilience: From forest restoration to emergency planning, strong public policy is essential for protecting communities.
- Spread awareness: Talk to friends, neighbors, and loved ones. Share accurate information—not panic—about the realities of fire in a changing world.
You don’t have to be near the flames to be part of the solution. Every small step you take now helps protect the people most at risk—and builds a safer, healthier future for everyone.
REFERENCES
1 Sherratt, M. (2025 July 21). Huge Oregon wildfire could become ‘megafire’ after blaze covers 95,000 acres. The Independent. https://www.the-independent.com/news/world/americas/oregon-cram-wildfire-megafire-b2792895.html.
2 Linley GD, Jolly CJ, Doherty TS, et al. (2022 March 19). What do you mean, ‘megafire’? Global Ecology and Biogeography, 31(10), 1906–1922. doi: 10.1111/geb.13499.
3 Stoof CR, De Vries JR, Ribau MC, et al. (2023 December 1). Megafire: An ambiguous and emotive term best avoided by science. Global Ecology and Biogeography, 33(2), 341–351. doi: 10.1111/geb.13791.
