Dangerous heat wave to grip eastern US this week with high humidity

Much of the central and eastern United States is bracing for a severe and prolonged heat wave this week, according to the National Weather Service. Temperatures are set to climb significantly ahead of the July Fourth holiday, with the added burden of high humidity making the conditions feel substantially hotter.

Millions of Americans are already experiencing intense heat, particularly in the Southwest, with areas like Phoenix and central Texas seeing temperatures around 100°F (38°C) on Sunday. The weather service also issued warnings for severe wildfire conditions across the West, where new fires were igniting. Over 130 million people in southern and Great Plains states were under moderate to severe heat risk conditions, a situation expected to expand and intensify throughout the week.

Forecasters predict several days of temperatures exceeding 100°F (38°C) across the lower Great Lakes, mid-Atlantic, and Mississippi and Ohio River valleys. Some areas, from the lower Great Lakes to New England, could see record-breaking highs later in the week. Major cities like New York, Philadelphia, Washington, Chicago, and St. Louis are expected to experience their highest temperatures of the year so far.

The oppressive heat, combined with high humidity, will create heat indexes ranging from 100°F to 110°F (40°C to 43°C), with potential peaks of 115°F (46°C). Meteorologists emphasize that this level of heat is dangerous for everyone, not just vulnerable populations. The extreme conditions are forecast to last into the following weekend across the Great Plains, Southeast, and mid-Atlantic regions.

“

That's heat that's impactful to anyone. It's not just older adults or younger children or people who are spending a ton of time outdoors, maybe straining themselves a little more than normal. This is heat that really could impact everyone, especially with people outdoors going into the holiday weekend.