Record-Breaking Temperatures Mask a Subtler Threat: Chronic Heat
Long-term exposure to high temperatures — even if they’re not abnormally high — is a growing health risk, particularly for outdoor workers and disadvantaged communities.
Phoenix has become a nerve-wracking bellwether for extreme heat. Arizona’s capital recently endured a three-week stretch when every day broke a heat record, with thermometers peaking at 117F (47C) on Sept. 28.
Yet even below the threshold of smashing records, Arizona is also “having hotter days more often, that last a little bit longer,” noted Erinanne Saffell, the state climatologist. Chronic heat at this scale poses its own dangers, without generating nearly as much attention as record-setting extremes. And there have been 92 days in Phoenix this year that were hotter than 95F but didn’t breach 110F.