Heat wave and high humidity will blast much of the eastern US this week, meteorologists say06/29/2026(Associated Press) - A heat wave will blast the eastern United States this week. The National Weather Service says temperatures rising ahead of the July Fourth holiday will feel hotter because of the high humidity that’s arriving with it. The weather service says several days of high temperatures will settle in across the lower Great Lakes, the mid-Atlantic and the Mississippi and Ohio River valleys. That's expected to last into next weekend across the Great Plains, Southeast and mid-Atlantic. Temperatures will reach well into the 90s and low 100 degrees F. Some cities could see their highest temperatures of the year so far as they host World Cup matches and celebrations for America’s 250th anniversary.Click here to visit the National Weather Service's HeatRisk map.