It’s not the weather: it’s a wandering ‘heat dome’

Last week it was Europe’s turn, with a slow-moving ‘heat dome’ that gave almost everybody from the United Kingdom to Poland three consecutive days of record-breaking temperatures. In Germany it hit 41°Celsius. That’s 106° Fahrenheit, if you live in the one country that still clings to British Imperial measures. (Hint: it’s not Britain.)

This week it’s America’s turn, with a similar ‘heat dome’ inflicting comparable temperatures on almost everywhere east of the Mississippi river. Even central...