It won't be quite so bad in the Northeast — but it won't be comfortable, either.
New York is expected to top 90 degrees for the third day in a row, meeting the definition of a heat wave, and the heat index around Washington will be close to 100. In New York, 20,000 customers lost power Monday as the grid struggled to keep up.
In the Midwest, behind a cold front, it's a different story. Chicago is expected to top out at a pleasant 79 degrees.
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That cold front will sweep through the Northeast and drop into the South at midweek, lowering temperatures, but the South will bake again this weekend: By Sunday, the heat index in some places could approach 115.