“It’s not just a figment of your imagination, and it’s not because everybody now has a smartphone,” said Jeff Berardelli, the chief meteorologist and climate specialist for WFLA News in Tampa. “We’ve seen an increase in extreme weather. This without a doubt is happening.”

It is likely to get more extreme. This year, a powerful El Niño developing in the Pacific Ocean is poised to unleash additional heat into the atmosphere, fueling yet more severe weather around the globe.

“We are going to see stuff happen this year around Earth that we have not seen in modern history,” Mr. Berardelli said.