Heat was gripping nearly the entire contiguous United States on Wednesday, with parts of 34 states under some kind of heat-related advisory, watch or warning.
Across the Pacific Northwest, temperatures are forecast to soar 10-20 degrees above average, resulting in highs in the 90s to 100s for coastal as well as inland cities. Seattle, Portland, Oregon, and Spokane, Washington, were all under heat alerts with the high heat expected to last through Friday.
This is the sixth heat wave for the region which just experienced its hottest June and July combination on record, and this relentless heat continues to fuel wildfires. Over 100 large wildfires are burning across more than a dozen states, with California's Dixie Fire as the largest in the nation at over half a million acres
California, specifically, is closing in on 1 million acres burned already this year. This is on the heels of 2020 which set the new state record at 4.3 million acres.
For the center of the country from the Gulf Coast to the Great Lakes, high heat combined with high humidity will lead to heat index values of 105-115 degrees. Chicago, St. Louis, Nashville, Tennessee, and Houston could all experience dangerous heat over the next several days.
This heat and humidity across the Midwest and the Great Lakes will fuel the risk for severe thunderstorms Wednesday afternoon and evening capable of producing damaging winds in excess of 60 mph, large hail and isolated tornadoes. For Chicago, this is the third straight day of severe weather.
And for the mid-Atlantic, Northeast and New England the rest of the week will face stifling heat where exceptionally high humidity will make temperatures in the 90s feel as hot as 100-110. This includes Washington, D.C., New York and Boston.
For New York City, where the heat index is forecast to reach 100 degrees Thursday, the excessive heat warning issued is a rare one for the month of August. The last time it was issued in August was five years ago, in 2016. They typically happen in June and July.
For the nation's capital, the heat index forecast for Thursday is 109 degrees. That heat could be deadly for anyone without access to air conditioning. And in Philadelphia on Thursday, the temperature will feel like 106 degrees.
Philadelphia, like most of America's cities, is getting distinctly hotter due to climate change. Summers have warmed in Philadelphia 3 degrees since 1970, and it now has five more days a year hitting 95 degrees or higher compared to 50 years ago.
And it's not just summer days that are getting hotter, but also summer nights. Summer nights are warming at an even faster rate compared to daytime temperatures, being linked to higher instances of heat-related illnesses.