The Northeast is sweltering in what's expected to become its fiercest heat wave yet this summer, and major cities have issued heat advisories and urged people to take cover in the face of nearly 100-degree heat.
Heat advisories and excessive heat warnings have been issued in New York City, where the temperature reached 94 degrees midday, as well as for all of Connecticut, Philadelphia, Washington, D.C. and parts of the Great Lakes and Ohio Valley regions. Temperatures were expected to reach the mid-90s in Washington and to flirt with 100 in Connecticut.
The National Weather Service said the heat index in New York — the temperature it feels like outside — could reach as high as 105 by Thursday and Friday. It will feel similar in Washington, thanks to a combination of heat and stifling humidity.
A dome of high pressure is to blame, according to forecasters. That dome isn't expected to move until a cold front moves in Friday.
Even the wee hours won't prove a respite from the heat, meteorologists warned. In the middle of the night Monday, Philadelphia will still feel like 90 degrees.
Weather.com meteorologist Jon Erdman noted that such a lack in a break from the heat has often contributed to heat-related deaths, and cities are taking precautions to protect those most vulnerable to the heat.
New York opened cooling centers for residents without air conditioning of their own, while Philadelphia urged people to check on their older friends, relatives and neighbors to ensure their homes were cool enough.
Public health officials urged people to avoid strenuous activity and spending too much time in the heat and to be sure to stay hydrated.
Still, meteorologist Erdman said, it could be much worse.
"If there is a small silver lining in this heat wave, we're not expecting triple-digit heat in most locations," he said.