Extreme Heat Warning in Effect
The Charleston, West Virginia, office of the National Weather Service, the U.S. weather agency, has issued an Extreme Heat Warning, an official alert for dangerous heat that can threaten health, covering Greenup County, one of the counties named in the alert, Carter County, Boyd County, Lawrence County, Perry County, Morgan County, Athens County, Washington County, Jackson County, Vinton County, Meigs County, and Gallia County, among others, running from June 30 at 1:09 until July 3 at 10:00.6
This warning is part of a broader dangerous heat pattern the National Weather Service says is expected across large swaths of the United States this week.2 The National Oceanic and Atmospheric Administration, a U.S. federal agency that monitors weather and climate, forecast dangerous levels of heat for the South and Midwest on Monday, June 29, 2026, making its forecast relevant to the warning and broader heat risk described here.3
How Many People Are Affected
About 97.9 million people — 29 percent of the population of the contiguous United States, meaning the 48 adjoining states and the District of Columbia in mainland North America — live in areas expected to have dangerous levels of heat.3 The National Oceanic and Atmospheric Administration projects the risk for heat-related impacts to reach major or extreme levels for around 220 million Americans.11
The National Weather Service has warned that heat indices will likely exceed 100 degrees across much of the central and eastern United States. In some areas, heat index values could climb as high as 109 degrees.4
What Heat Index Means
The heat index measures how hot it actually feels outside, combining temperature and humidity.3 A person standing in direct sun could perceive the temperature as being higher by up to 15 degrees Fahrenheit above the stated heat index.3
Heat cramps or heat exhaustion are likely at elevated heat index levels after long exposure or exercise.3 Heat stroke is life-threatening and requires emergency medical care, with symptoms that can include hot dry skin, nausea, confusion, and unconsciousness.4
Who Is Most at Risk
Health officials say anyone can suffer from heat-related illness, but those at highest risk include older adults, people with chronic health conditions, children, athletes, and outdoor workers.4 Heat exhaustion symptoms may include fainting, rash, fatigue, nausea, or cool moist skin.4
Anyone experiencing those symptoms should begin cooling the body immediately.4
Duration Through July 4 Weekend
The National Weather Service says heat is likely to continue across the eastern United States through the Independence Day holiday weekend, the U.S. holiday period commemorating the country's declaration of independence. Overnight temperatures in some areas may remain in the 70s to near 80, providing little relief.4
The Extreme Heat Warning for the affected Ohio and West Virginia counties runs through July 3 at 10:00.6 Residents in the warned areas — including Greenup County, Carter County, Boyd County, Lawrence County, Perry County, Morgan County, Athens County, Washington County, Jackson County, Vinton County, Meigs County, and Gallia County — should monitor official guidance closely.
Check the forecast for your city to see whether dangerous heat is heading your way.