February 24, 2024
U.S. billion-dollar weather disasters set an all-time record in 2023

Led by a record-costly swarm of severe weather episodes, the contiguous United States suffered 28 billion-dollar weather disasters in 2023, the highest number in inflation-adjusted data going back to 1980, according to NOAA. The former record was 22, set in 2020.

“For millions of Americans impacted by a seemingly endless onslaught of weather and climate disasters, 2023 has hit a new record for many extremes,” said NOAA Chief Scientist Sarah Kapnick. “Record warm U.S. temperatures in December, a record-setting number of U.S. billion-dollar disasters in 2023, and potentially the warmest year on record for the planet are just the latest examples of the extremes we now face that will continue to worsen due to climate change.”

The total cost of 2023’s billion-dollar weather disasters, $92.9 billion, was the ninth-highest on record. NOAA’s 2023 billion-dollar weather disaster list included 19 severe storm events, two tropical cyclones, four floods, one winter weather event, one drought, and one wildfire event.

The cost of the 19 severe storm events in 2023 was $54 billion, setting a new record for costliest year on record for that peril (previous record: $44 billion in 2011). The most expensive disaster of 2023, the $14.5 billion drought and heatwave that affected much of the South and Midwest, ranked as the nation’s seventh-costliest drought since 1980. Billion-dollar events now account for over 85% of the total U.S. losses for all weather-related disasters; this fraction was just 75% in 1980-2000.

Billion-dollar weather disasters in the U.S. killed 492 people in 2023, compared to 474 in 2022 and 688 in 2021. The deadliest disaster of 2023 was the summer-long drought and heat wave focused across the southern tier of states, which was blamed for 247 deaths. The second-deadliest was the Maui, Hawai’i firestorm, which killed 100 people on August 8 — the deadliest U.S. wildfire in over a century.

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Billion-dollar disasters are increasing in number

NOAA’s 1980-2023 annual inflation-adjusted average is 8.5 billion-dollar events, but over the past five years (2019-2023), the annual average has more than doubled, to 20.4 events. In a blog post, NOAA said: “The number and cost of weather and climate disasters are increasing in the United States due to a combination of increased exposure (i.e., more assets at risk), vulnerability (i.e., how much damage a hazard of given intensity—wind speed, or flood depth, for example—causes at a location), and the fact that climate change is increasing the frequency of some types of extremes that lead to billion-dollar disasters (Fifth U.S. National Climate Assessment (2023).”

A low-impact hurricane season

As noted in our 2023 hurricane-season roundup, three Atlantic named storms made a U.S. landfall in 2023, with Hurricane Idalia’s landfall in the Florida Big Bend region being the only billion-dollar one ($3.6 billion). The other landfalls were Tropical Storm Harold in South Texas (little damage) and Tropical Storm Ophelia in North Carolina ($375 million in damage, according to Gallagher Re). In addition, Tropical Storm Hilary moved into Southern California after hitting Mexico, causing several hundred million in damage to the U.S., and Typhoon Mawar did over $1 billion in damage to Guam.

While tropical cyclones often wreak more U.S. havoc than severe storms, this year the tables were turned: the 19 billion-dollar severe weather events caused more than 10 times more damage than the single billion-dollar hurricane.

Warmest December on record for the U.S.

NOAA also reported that December 2023 torched the previous record-warm December, set just two years ago, to rank as the nation’s warmest in data going back 129 years. The monthly nationally averaged temperature of 39.97 degrees Fahrenheit was more than 7 degrees Fahrenheit higher than the 20th-century average of 32.68 degrees Fahrenheit and topped the previous record value from December 2021 by 0.63 degrees Fahrenheit. A group of seven states from Montana to Wisconsin had their warmest December on record. Every one of the contiguous states outside the South had its top-ten-warmest December and in many cases a top-five warmest.

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What truly marked December 2023 was an astounding lack of bitter cold. Very few locations managed to get down to zero Fahrenheit, even in traditionally frigid states such as Minnesota. An archive of daily record highs and lows maintained by independent meteorologist Guy Walton sheds light on just how “non-cold” December was. Across the contiguous U.S., there were only 51 daily record lows – the lowest total for any month going back to October 1921 – and the ratio of daily record highs (3,408) to daily record lows (51) was an astonishing 67 to 1, the highest since March 1910. Since there were many fewer observing stations online in the 1910s and 1920s, those older values may be biased on the low side, which makes the lack of cold records in December 2023 even more impressive.

As for moisture, Delaware, Minnesota, and New Jersey had their wettest December on record, and 12 other states had top-ten wettest Decembers. No state had a top-ten-driest December. Despite all the precipitation, it was more of a rainy than a snowy month: the widespread warmth contributed to a lack of snowfall that left the nation with record-low snow cover going into the holiday period.

Fifth-warmest year on record for the U.S.

The year as a whole came in as the fifth warmest on record nationally, 2.4 degrees Fahrenheit above the 20th-century average. It was the warmest year on record for five states in the Southern Plains and New England: Massachusetts, New Hampshire, Mississippi, Louisiana, and Texas. Every state from the Mississippi Valley eastward had a top-ten warmest year, and none of the contiguous states were cooler than average.

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The contiguous U.S. has now warmed by around 2.0 degrees Fahrenheit (1.1 degrees Celsius) since 1895, which is close to the global average. That’s a noteworthy trend given that the U.S. was lagging much of the globe in long-term warming during the late 20th century. The “cooler” years of this century, such as 2013, 2014, and 2019, would have been considered average a few decades ago, while the warmest eight years of the entire record have all occurred since the turn of the century, including the top five: 2012 (55.28°F), 2016 (54.92°F), 2017 (54.55°F), 2021 (54.51°F), and 2023 (54.43°F).

The year as a whole was on the dry side when averaged nationally, ranking as the 43rd driest in the 129-year database. Major drought relief in California and the Southwest from generous winter rains followed by Hurricane Hilary helped vanquish the tail end of widespread dry conditions that were fostered in part by the 2020-23 La Niña. By year’s end, only about a third of the nation was experiencing drought conditions (D1-D4 on the U.S. Drought Monitor scale). It was the eighth driest year on record in Louisiana, and a top-ten wettest year for all six New England states (Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and Maine).

This story was first published Jan. 9, 2024 by Yale Climate Connections. Sign up to receive notices of new postings here.