Showers of ash, giant waves, and massive explosions weren't the the only things locals had to worry about when Tonga's Hunga Tonga-Hunga Ha'apai volcano erupted last January in the South Pacific. Lightning also made an appearance, and a whole lot of it—so much, in fact, that the "cataclysmic eruption" smashed "all records." That's according to Vaisala's "Annual Lightning Report," which tracks global lightning events throughout the year. Among the report's findings: After the Jan. 15 eruption, more than 25,500 lightning events were triggered in just five minutes. Over six hours, that number jumped to almost 400,000.
"At the peak of the eruption, half of all global lightning was concentrated around the volcano," the report notes. "It's the most extreme concentration of lightning that we've ever detected," Vaisala meteorologist Chris Vagasky tells CNN. "We've been detecting lightning for 40 years now, and this is really an extreme event." Robert Holzworth of the University of Washington's World Wide Lightning Location Network concurs, adding, "The Hunga eruption was absolutely impressive in its lightning activity." "I can't imagine what the people on the islands would have been going through, with a huge ash cloud overhead, a tsunami flooding everything they own, and cloud-to-ground lightning coming down around them," Vagasky told Reuters in February. "It must have felt apocalyptic."
The US saw its own lightning uptick in 2022, which logged more than 198 million lightning strokes—about 4 million more than the previous year, and 28 million more than in 2020. Researchers are keeping an eye on climate change as a possible factor in the upward trend, as lightning tends to happen in warmer temperatures. "Tends" is the operative word: Last year in Buffalo, New York, a city not exactly known for its tropical weather, Vaisala's team noted 1,100 lightning strokes during a lake-effect snowstorm: a phenomenon in which "cold air blows over warm lake water," causing "extreme instability in the atmosphere" that can lead to excess lightning, per CNN. (Read more volcano stories.)