In early September, a lot of people who live in hurricane-prone parts of the United States started noticing that it had been an eerily quiet summer. On average, there are 14 storms each year in the Atlantic between June 1 and December 1.

But as of August, there had only been three storms.

What was going on, many wondered? Did this mean there would be a welcome respite from recent years of record-breaking storms? After all, there were a whopping 21 total storms in 2021. And, in 2020, there were so many storms that forecasters ran out of letters in the alphabet to name them.

But federal forecasters were adamant: the apparent 2022 lull meant little, they warned, because the number of storms tells you little about the severity of any given hurricane season. It only takes one big storm hitting land to cause major destruction.

Plus, peak hurricane season is in the fall, so there was still time for a glut of storms.

"I urge everyone to remain vigilant as we enter the peak months of hurricane season," said Gina Raimondo, Secretary of the Commerce Department, which includes the National Oceanic and Atmospheric Administration. NOAA updated its hurricane forecast, but only to say that the forecast basically had not changed: scientists were still expecting at least 14 storms in 2022, and people in hurricane-prone areas should stay prepared for storms.

"It was actually, kind of, fear and dread," says Jamie Rhome, the acting director of the National Hurricane Center, thinking back on the quietest part of the Atlantic hurricane season. "I felt like people were letting their guard down."

That dread was justified. By the end of September, two deadly storms had hit the U.S. and killed more than 150 people: Hurricane Fiona in Puerto Rico, and Hurricane Ian in Florida.

In the end, the 2022 Atlantic hurricane season was among the most deadly and damaging in modern history. It was the third-most expensive hurricane season to date, according to estimates by the reinsurance company Munich Re, with total losses of about $110 billion.

The 2022 hurricane season exemplifies some of the most dangerous effects of climate change on storms. Climate change is not causing more storms to form in the Atlantic, according to the latest climate research. Instead, a hotter Earth makes it more likely that the storms that do form will become big and powerful.

"You're getting the same number of storms each year, but they're punching harder," says Rhome.

That makes storms more deadly.

Flooding was the main cause of death and destruction from both Hurricane Ian and Hurricane Fiona. Much of the inland flooding from Ian was caused by extreme rain. "A warming climate holds more moisture, and therefore can produce generally more rain," explains Rhome.

The other major source of flooding was from storm surge – the wall of ocean water that storms push onto land, like an extremely high tide. The more powerful the storm, the more water it pushes inland. "A rising sea level makes the storm surge worse," says Rhome.

That was on full display this year. Sea levels in Florida where Hurricane Ian made landfall have already risen about 1 foot because of global warming. That extra water exacerbated flooding.

In all, 2022 was a sobering reminder that climate change makes the most destructive storms more likely, and that even relatively quiet hurricane seasons can quickly turn deadly.