A new heat risk map from federal authorities warns that large parts of the United States may soon face dangerously high temperatures. Forecasters are predicting triple-digit heat index values across numerous states in the coming days.
Extreme heat is the deadliest form of weather in the United States on average. Federal agencies highlight that prolonged exposure to high heat index values can quickly become hazardous. The combination of heat and humidity escalates the risk of heat-related illnesses. It can also exacerbate existing health conditions, especially in older adults, children, and people working outdoors.
The National Weather Service’s (NWS) Climate Prediction Center (CPC) shared a map recently. This map pinpoints states most likely to experience extreme heat from June 30 to July 6. An accompanying graphic indicates that more than half of the U.S. could see heat index values over 100 degrees Fahrenheit. This situation raises concerns about public health impacts and stresses on infrastructure.
“Strong mid-level high pressure centered over the Southeast is expected to move west and expand north and northwest, increasing extreme heat chances for much of the Central U.S., Gulf States, and Eastern U.S.,” the message stated.
While the heat is still a week away, local NWS offices have not yet issued warnings. However, heat-related alerts are active in the Southwest.
Understanding the Heat Index
The heat index, or “feels-like” temperature, combines air temperature with humidity. High humidity hinders sweat evaporation, making it harder for the body to cool down and increasing the risk of heat illness.
Extreme Heat Risk Map: U.S. Overview
According to the CPC map, the Mid-Atlantic region faces the highest risk of extreme heat during the June 30 to July 6 period. It forecasts a greater than 60% chance of extreme heat in parts of the Mid-Atlantic, including Washington D.C., from June 30 to July 2. Temperatures could reach up to 95 degrees Fahrenheit, with heat indices possibly reaching at least 105 degrees Fahrenheit.
There is a moderate risk, with a 40-60% chance of extreme heat, across parts of Texas, Oklahoma, Kansas, and along the East Coast. This stretches from South Carolina to southeastern Pennsylvania and southern New Jersey, affecting cities such as Charlotte and Philadelphia.
“The Texas Panhandle and parts of western Oklahoma may reach 100 degrees Fahrenheit with heat index values near 105 degrees Fahrenheit from June 30 to July 3,” the outlook noted.
A slight risk, defined as a 20-40% chance of extreme heat, is indicated for much of the eastern U.S. and parts of the Great Plains from June 30 to July 6. Temperatures might reach at least 90 degrees Fahrenheit, with heat index values potentially reaching 100 degrees Fahrenheit or higher in lower elevations. Record-high nighttime temperatures in the high 70s to low 80s degrees Fahrenheit are possible.
States at risk of extreme heat include Colorado, South Dakota, Nebraska, Kansas, Wyoming, New Mexico, Texas, Oklahoma, Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Florida, Tennessee, Kentucky, Illinois, Indiana, Ohio, West Virginia, Virginia, North Carolina, South Carolina, Maryland, Delaware, Pennsylvania, New Jersey, and New York.
Differentiating Heat Exhaustion and Heat Stroke
Heat exhaustion is the body’s early warning that it struggles to cool itself during prolonged heat exposure. Symptoms are heavy sweating, dizziness, headache, nausea, weakness, and a fast but weak pulse, frequently paired with cool, pale, or clammy skin. It usually resolves with a cooler environment and hydration. However, officials emphasize that it should not be ignored as it can worsen.
Heat stroke is a life-threatening emergency where the body fails to regulate temperature. The body temperature can exceed 103 degrees Fahrenheit. Symptoms include confusion, slurred speech, severe headache, rapid strong pulse, and loss of consciousness, with skin turning hot and either dry or damp. Mental changes signal brain involvement, requiring immediate medical attention to prevent organ damage or death.