Eastern U.S. braces for more long days of dangerous heat

Tens of millions of people across the Midwest and East braced Sunday for another sweltering day of dangerously hot temperatures as a rare June heat wave continued to grip parts of the U.S.

Most of the northeastern quadrant of the country from Minnesota to Maine was under some type of heat advisory Sunday. So were parts of Arkansas, Tennessee, Louisiana and Mississippi, the National Weather Service said Sunday.

Sunday marked the second straight day of extreme heat across the Midwest and East Coast. Heat indices on Saturday hit 103 in Chicago and 101 in Madison, Wisconsin, turning that city’s annual naked bike ride into a sticky and sweaty affair.

The temperature reached 80 degrees in the Chicago area by 7:30 a.m. Sunday. Forecasts called for heat indices of between 100 and 105.

The heat index in Pittsburgh was expected to top 105. The temperature in Columbus, Ohio, was 7 at 8:30 a.m. Highs there were expected to reach 97 with a heat index around 104.


Forecasts called for a heat index of 100 F in Philadelphia on Sunday, with 108 on Monday.

Forecasters warned the heat index in Cromwell, Connecticut, would reach 105 on Sunday, which could make life brutal for golfers during the final round of the Travelers Championship.

In St. Louis, Cincinnati Reds shortstop Elly De La Cruz, and Seattle Mariners reliever Trent Thornton, facing the Cubs in Chicago, got sick Saturday while playing in the extreme heat.

Meteorologists said a phenomenon known as a heat dome, a large area of high pressure in the upper atmosphere that traps heat and humidity, is responsible for the extreme temperatures.

Mark Gehring, a National Weather Service meteorologist in Sullivan, Wisconsin, said this usually takes hold in mid-July or early August. The most unusual facet of this heat wave is the sheer amount of territory sweltering under it.

“It’s basically everywhere east of the Rockies,” he said, referring to the Rocky Mountains. “That is unusual, to have this massive area of high dewpoints and heat.”


MAP: shows the degrees of departure above each area's usually high temperature.  Yellow shows a less than 5 degree departure from normal; light orange 5-10 degrees higher; dark orange 10-15 degrees; red 15-20 degrees above normal. (Nathional Weather Service)