Lightning strikes in the Arctic tripled from 2010 to 2020, a finding University of Washington researchers attribute to rising temperatures due to human-caused climate change. The results, researchers say, suggest Arctic residents in northern Russia, Canada, Europe and Alaska need to prepare for the danger of more frequent lightning strikes.

The study, published March 22 in Geophysical Research Letters, used data from the UW-based World Wide Lightning Location Network to map lightning strikes across the globe from 2010 to 2020. WWLLN sensors detect the short burst of radio waves emitted during a lightning strike.

The new study found the number of lightning strikes above 65 degrees north latitude during the summer months tripled from 2010 to 2020 as compared to the total number of lightning strikes over the entire globe during the same period.

“With long periods of ice-free ocean and increasing shipping in the Arctic, you’re going to have the same problem you have at lower latitudes — when there’s a lot of people and they don’t know about the lightning threat and it becomes a problem,” said lead author Robert Holzworth, a UW professor emeritus of Earth and space sciences.

Holzworth and his colleagues analyzed the frequency of Arctic lightning strikes occurring during the summer months of June, July and August from 2010 to 2020. They found the percentage of lightning strikes occurring in the Arctic tripled from 0.2% of global lightning strikes in 2010 to 0.6% in 2020. The actual number of lightning strikes above 65 degrees north increased from about 18,000 in 2010 to over 150,000 in 2020.