The number of billion-dollar weather disasters in the United States has more than doubled in recent years, as devastating hurricanes and ferocious wildfires that experts suspect are fueled in part by climate change have ravaged swaths of the country, according to data released by the federal government Wednesday.

Since 1980, the United States has experienced 241 weather and climate disasters where the overall damage reached or exceeded $1 billion, when adjusted for inflation, according to data from the National Oceanic and Atmospheric Administration. Between 1980 and 2013, according to NOAA, the nation averaged roughly half a dozen such disasters a year. Over the most recent five years, that number has jumped to more than 12.

"We had about twice the number of billion dollar disasters than we have in an average year over the last 40 years or so,” Deke Arndt, chief of the monitoring branch at NOAA’s National Centers for Environmental Information, told reporters Wednesday.

NOAA said 14 separate weather and climate disasters, costing at least $1 billion each, hit the United States during 2018. The disasters killed at least 247 people and cost the nation an estimated $91 billion. The bulk of that damage, about $73 billion, was attributable to three events: Hurricanes Michael and Florence and the collection of wildfires that raged across the West.

Yet 2018 did not set the record for the most expensive year for such disasters. That distinction belongs to 2017, when Hurricanes Harvey, Irma and Maria combined with devastating Western wildfires and other natural catastrophes caused $306 billion in total damage. They were part of a historic year that saw 16 separate events that cost more than $1 billion each.

But the most recent numbers continue what some experts call an alarming trend toward an increasing number of billion-dollar disasters, fueled, at least in part, by the warming climate.

“There’s this knot in your stomach where you know there is some big piece of this that is probably coming from climate change, but at the same time, there are a lot of moving parts,” said Solomon Hsiang, a public policy professor at the University of California at Berkeley, who has studied how natural disasters affect societies.

Many factors contribute to the cost of any one disaster. For instance, a hurricane that hits a heavily populated area, such as Hurricane Sandy in 2012 or Hurricane Harvey in 2017, is likely to have a far higher economic impact than one that hits a less crowded part of the country. The nation’s growing population, inconsistent building codes and the fact that many cities and infrastructure sit near coasts or along rivers also play a role. But increasingly, experts say, so does climate change.

“The recent past is likely prologue,” said Mark Muro, a senior fellow at the Brookings Institution, who has studied the economic impact climate change is likely to have on different parts of the country in the coming decades.

Separately on Wednesday, the National Aeronautics and Space Administration and NOAA released data that officially made 2018 the fourth-warmest year since 1880. The last four years have been the warmest on record, and nine of the 10 warmest years have been since 2005. Analyses from NASA and NOAA also show that in most or all of these years, the Earth was at least 1 degree Celsius, or 1.8 degree Fahrenheit, warmer than it was in the preindustrial era of the middle to late 1800s.

“It was quite clearly the fourth warmest year in our record, which goes back to 1880, and probably was warmer than many hundreds of years before that,” said Gavin Schmidt, director of the Goddard Institute for Space Studies at NASA, which produces the temperature record.

The agencies' data also showed that 2018 was the wettest in the past 35 years in the U.S., and the third wettest since record keeping began in 1895.

Hsiang said that climate models predict that the country can expect more of the most catastrophic and costly events over time — namely, more powerful hurricanes slamming into the East and Gulf coasts and more intense wildfires in the West. Scientists also have predicted that a warming climate will fuel more severe droughts, longer wildfire seasons and more frequent floods.

Climate change has helped to shape the severity of at least some of the natural disasters in recent years, said Kerry Emanuel, a top hurricane expert at the Massachusetts Institute of Technology. For instance, Emanuel has published research suggesting the enormous rainfall Hurricane Harvey dumped on Houston was made more possible because of climate change.

However, that’s different than saying that the overall aggregate damage figures are definitely rising because of climate change. That hasn’t been proven to a 95 percent certainty, Emanuel said, but there are reasons to suspect climate change is playing a notable role.

“If you’re assessing a risk, a risk you have every reason to think exists, nobody would ever require that certainty,” Emanuel continued. “Generals in the battlefield would never wait for 95 percent certainty.”

There are also projections that the impact of climate change should soon be making itself felt in the cost of at least some disasters. A 2014 analysis by the Rhodium Group, for instance, projected that by 2030, the average damage from hurricanes and nor’easters, to the East and Gulf coasts in particular, should be $3 billion to $7.3 billion higher each year. That’s if climate change continues unabated.

The trend itself is an unsustainable one, Hsiang said.

“These costs are enormous. If we really continue to sustain costs like this going forward, many elements of the way we’ve managed resources in society are just not financially sustainable,” he said. “We are spending huge amounts of money on disaster relief . . . We’re always responding to a disaster by picking up the pieces after they occur.”

The distribution of damages from billion-dollar disasters has long been dominated by hurricanes, which can wreak havoc over multiple large states and millions of people in a matter of hours. Since 1980, hurricanes traditionally have caused more than half the total losses tallied by the government. But the Camp Fire in the fall, which became the deadliest and most destructive wildfire in California history, also fueled a historically damaging wildfire season. NOAA estimated that wildfires accounted for $24 billion of damage last year, well in excess of the record of $18 billion, set in 2017.

While fires and hurricanes are responsible for the bulk of disaster-related damages — and also disaster-related headlines — a number of other events also routinely have surpassed the billion-dollar mark over the years. They include droughts, hailstorms, winter storms and tornadoes.

And while calamities have struck nearly every corner of the country, climate change is likely to make the impact disproportionate going forward — not just from hurricanes and other storms, but also from economic losses associated with an ever-growing number of hotter days.

“There’s no doubt, the Southwest is the epicenter of negative economic impacts in coming decades,” Muro said. “In the big picture, the Southeast and the Gulf Coast are the center of climate harm in the United States.”