Millions of Americans are being advised to stay out of the sun this week as a widespread heatwave is expected to bring dangerous conditions to 14 states. The National Weather Service (NWS) has issued Heat Advisories, warning that the heat index, often referred to as the 'feels like' temperature, will surpass 100°F in many areas, particularly on Thursday and Friday.
The heat index accounts for humidity, making it feel hotter than the actual air temperature. In regions with high humidity, a 90°F day can feel like 105°F. AccuWeather meteorologists indicate that humid air from the Gulf of Mexico is contributing to the rising temperatures in the central U.S., while the Northeast will also experience extreme humidity pushing the heat index as high as 103°F.
Specific areas under advisories include New York, New Jersey, Connecticut, Delaware, Massachusetts, Vermont, and parts of eastern Pennsylvania. The Midwest, including Indiana, Michigan, and Ohio, is expected to experience these dangerous conditions starting Wednesday afternoon. In the South, Texas, Oklahoma, and Kansas are anticipated to face the brunt of the heat, with 'feels like' temperatures ranging from 105°F to 108°F on Wednesday and Thursday. Large portions of Central California, the Sacramento Valley, and the Bay Area could see temperatures reach 105°F from Thursday into the weekend.
Forecasters predict that some daily record highs may be set across multiple locations for several days. In Maryland and North Carolina, daily temperature records are expected to fall on Friday, with Raleigh potentially breaking a record from 2002 if temperatures reach 99°F. 'Feels like' temperatures are projected to exceed 100°F in Maryland, Virginia, and the Carolinas on Friday.
Overall, warmer and more humid air is anticipated to affect over 200 million people across more than 27 states, stretching from Colorado to New York and from the Gulf Coast to the Canadian border. The NWS advises residents in affected areas to drink plenty of fluids, stay in air-conditioned spaces, avoid direct sun exposure, and check on vulnerable relatives and neighbors.
High heat index values can lead to heat-related illnesses such as heat exhaustion and heat stroke. Heat exhaustion symptoms include heavy sweating, fatigue, cool and clammy skin, a fast and weak pulse, muscle cramps, dizziness, nausea, and headaches. Heat stroke, a more severe and potentially deadly condition, can develop rapidly and may present with symptoms such as a throbbing headache, confusion, slurred speech, nausea, dizziness, a fever above 103°F, and potentially red, dry, or damp skin, a rapid pulse, or loss of consciousness. Immediate medical attention is recommended for individuals experiencing heat stroke symptoms.
Simultaneously, severe thunderstorms are forecast for the Upper Midwest, including Wisconsin, Minnesota, Illinois, Iowa, and Michigan. These storms, characterized as supercells, could bring heavy rain, large hail, and isolated tornadoes. Major cities such as Minneapolis, Chicago, Milwaukee, Kansas City, Missouri, and Des Moines, Iowa, are at risk for severe weather and potential travel disruptions.