Global Extreme Weather and Climate Change Dashboard

A magnitude-integrated companion to North America's event-count index above -- how intense and how long each year's most extreme heat wave was, not just how many qualified. Same HWMId-style construction as the global magnitude index. Unit: magnitude index (dimensionless).

Source: NOAA GHCN-Daily, GCOS Surface Network (GSN) stations, North America subset

Computing trend…

Same construction as the global Heat Waves magnitude index (see Methodology), restricted to GSN stations within North America. 2023 ranks as the single highest year in the record (2.06, about 1.6 times the next-highest year), matching the record 2023 North American summer heat (including Phoenix's 31 consecutive days above 110°F); 2021 stands elevated above its immediate neighbors (2020, 2022), matching the June 2021 Pacific Northwest heat dome. Same borderline continent-density note as the event-count index above.