Aftermath of Hurricane Ida in Louisiana

2021’s deadliest, coldest, most expensive U.S. disasters, by the numbers

In yet another year of extremes, the United States in 2021 faced the “second highest number of billion-dollar weather and climate disasters on record,” and suffered the largest number of disaster-related deaths in the contiguous U.S. in a decade, the National Oceanic and Atmospheric Administration said Monday.

Tropical cyclones racked up the highest total cost compared to other severe weather events, adding up to a total of $78.5 billion, according to the 2021 Annual U.S. Climate Report. Hurricane Ida alone, which dealt a particularly devastating blow to Louisiana, caused $75 billion worth of damage, making it the “most costly event of 2021,” as well as one of the top five most expensive hurricanes since 1980, when record keeping began. Extreme heat, related to drought, caused the most deaths, followed by the winter storm that hit Texas and other states in February.

READ MORE: Louisianans are living in tents and cars after losing homes to storms

“2021 is another example of warmer extremes becoming increasingly frequent,” said Becky Bolinger, a climatologist based at Colorado State University. And the rise in the number of these billion-dollar events shows just how vulnerable we are to climate extremes.

noaa billions disasters

Graphic by Megan McGrew/PBS NewsHour

It’s no secret that, as our planet warms, conditions on the ground have become increasingly ripe for weather-driven catastrophe. (Think severe drought in the West that dries out vegetation, creating ample fuel for out-of-control wildfires.) Severe weather events don’t always directly correlate to climate change — although researchers have gotten better at connecting specific events to climate change through attribution science. This report adds to scientists’ understanding of how our climate system has changed over time, and the growing consequences we can expect to see in the U.S. due to unchecked global warming.

WATCH: Climate change is making extreme weather events more common

Here’s a look at some of the main takeaways from the report.

The human toll of severe weather

Twenty different so-called “billion-dollar” events collectively killed a known total of 688 people — that’s the highest number of disaster-related deaths in the contiguous U.S. since 2011 (if counting U.S. territories, the deadliest year by this measure was 2017, when hurricanes devastated Puerto Rico).

Recovery efforts following last year’s disasters cost the nation around $145 billion, which NOAA’s National Centers for Environmental Information characterized as the third-highest cost on record.

Regions of the country were affected differently by these billion-dollar disasters, and few evaded them entirely.

  • The snowstorm and cold snap that hit a large swath of the Great Plains, Texas and Mississippi River Valley in February was the most costly winter storm on record, clocking in at $24 billion. It was also “the coldest event observed across the contiguous U.S.” in more than three decades, according to NOAA.
  • Not only did tropical cyclones overall wreak the most damage in dollars, but 2021 had the “third-most active Atlantic hurricane season” ever recorded.
  • 1,376 tornadoes were reported in the contiguous United States in 2021, a higher than average number. In the final month of the year, there were 193 confirmed tornadoes, the largest number for any December on record.
2021 billion dollar disasters

Map of the U.S. plotted with 20 separate billion dollar disasters that occurred in 2021. Map courtesy of NOAA

Andrew Joyner, who serves as Tennessee’s state climatologist, told the PBS NewsHour in an email that his state contended with at least three billion-dollar disasters.

Joyner, also an associate professor of geosciences at Eastern Tennessee State University, noted the impact of severe weather events that don’t make the annual billion-dollar list but still cause significant damage in the communities they hit. Joyner said Tennessee’s previous 24-hour rainfall record was “shattered” last summer, causing major flooding and loss of life in parts of the state.

“Not only is this a new state record, it is also the highest 24-hour rainfall amount for any non-coastal state in the country,” Joyner added.

noaa billions disasters cost

Graphic by Megan McGrew/PBS NewsHour

Severe winter storms will continue to pose a major threat even as the planet warms. Bolinger, who also serves as Colorado’s assistant state climatologist, told the PBS NewsHour over email that February’s billion-dollar winter storm is evidence that “cold extremes can still happen in a warming climate and are something we still need to prepare for.”

Nearly one in three Americans have been personally affected by an extreme weather event in the last two years, according to an Oct. 2021 poll from the PBS NewsHour, NPR and Marist. These events can destroy homes and businesses, as well as threaten the socioeconomic stability of those affected. People who don’t have the financial resources to recover from these events when they’re affected, particularly marginalized groups, including communities of color, low-income and rural communities, are most vulnerable in the face of their fallout.

Rising temperatures

Since national record keeping on temperature began in 1895, the national temperature trend has been warming at a rate of 0.16°F per decade, or 1.6°F per century, Karin Gleason, a meteorologist at NOAA, wrote in an email. But in the last few decades, that trend has increased to 0.49°F per decade or almost 5°F per century.

This “upward trend” is consistent with global averaged temperatures as well, which have risen at more than twice their previously recorded per decade rate since 1981, according to NOAA. Around the world, scientists have offered dire warnings about expected consequences for humanity — like more droughts, heat waves and heavy precipitation — if global temperatures rise more than 1.5° Celsius above pre-industrial levels – a threshold we are expected to reach within the next eight to 30 years if we fail to collectively reduce our greenhouse gas emissions.

According to the new report:

  • The six warmest years on record have occurred since 2012.
  • 2021 ranked overall as the fourth-warmest year since record-keeping began 127 years ago.
  • December was the warmest on record for the contiguous U.S., replacing the previous record holder, December of 2015.
  • Around 14.6 percent of the contiguous U.S. saw its warmest recorded June in 2021, which NCEI characterized as “the largest extent of record warm temperatures on record for the U.S.” during that month.

Bolinger said that “December continues to be one of the months most sensitive to that warming, with 10 states experiencing their warmest December on record.”

noaa temp

Map courtesy of NOAA’s National Centers for Environmental Information

But an overall trend of warming doesn’t mean that cooler years aren’t possible or expected. Gleason cited 2019 as an example of a recent comparatively “cooler” year where temperatures were still around 0.7°F above average. Still, in the future, researchers expect to see more warmer years than cooler ones.

Quality weather and climate data sets are “critical” for scientists’ understanding of “how our climate system has changed over the years,” Gleason said in an email, adding that they “expect to see more frequent extremes in heat waves, droughts, floods and warmer overnight temperatures as a result of global warming.”