The Critical Flaw in Single-Event Hurricane Climate Attribution

Less than a month has passed since the official end of the 2025 hurricane season for the Northern Hemisphere. Interestingly, 2025 statistics show that Accumulated Cyclone Energy (ACE) in the northern hemisphere was roughly 20% below the 1991-2020 mean while the number of major hurricanes and major hurricane days were down about 27% and 36%, respectively, compared to their 30-year averages (shown in parentheses).1