Heat dome expands across central United States, prompting heat advisories

What This is

• A heat dome is expanding across the central United States, trapping heat and humidity over large areas for days.
• Forecasts call for widespread highs above 100°F, with some places in the Rockies, Plains, and Texas corridor potentially topping 110°F.
• Heat advisories and warnings cover tens of millions of people, with estimates ranging from about 70 million to more than 100 million affected.
• Forecasters warn that warm overnight lows will limit recovery from the heat and raise the risk of heat stress.
• Health officials and meteorologists urge people to use air conditioning or cooling centers, drink water, and check on children, older adults, and people with medical conditions.
• Some forecasts warn the heat dome could be unusually strong and slow-moving, increasing the chance of record or near-record temperatures in many states.
• In parts of the southern Plains, heat combined with existing drought is raising concerns about added stress on agriculture and water conditions.
• Scientists cited in coverage link the growing frequency and severity of these heat extremes to rising greenhouse gas levels and human-caused climate change.

Why This Matters

• Extreme heat is one of the deadliest weather hazards, especially when hot nights prevent the body from cooling down.
• The scale of the advisories tests whether cities and states can protect people without reliable air conditioning, including the unhoused and outdoor workers.
• Long stretches of high heat can strain power grids, raise electricity bills, and increase the risk of outages during peak demand.
• Heat layered on top of drought can worsen crop and livestock losses, pushing up food costs and financial stress for rural communities.