‘Extraordinarily hot’: US heatwave stretches on with millions still under warnings

Millions of Americans are experiencing extreme heat as a heatwave, driven by another heat dome, continues across the central and southern United States. On Sunday, at least 40 million people were under heat warnings, with heat indexes exceeding 100°F from Minnesota to Mississippi and extending into California and Nevada. Parts of the Southwest could reach 120°F. This phenomenon traps heat, prolonging high temperatures and causing dangerous conditions, particularly for vulnerable populations. While some relief is expected mid-week for the central US, high temperatures may return by the weekend. The article notes that extreme heat events are exacerbated by the climate crisis.

A severe heat wave is impacting central and southern parts of the United States for a second consecutive day, with tens of millions under extreme heat warnings. Heat indices are forecast to exceed 105°F from Memphis to Montana and Las Vegas, with parts of the Southwest potentially reaching 120°F. This prolonged heat is attributed to a heat dome, a phenomenon that traps atmospheric heat. Authorities are warning vulnerable populations, including children and older adults, about the risks of heat stroke and recommending staying in air-conditioned spaces, drinking water, and limiting sun exposure. The continental U.S. experienced the second-hottest first half of the year on record in 2026.

Approximately 70 million people across the southern and central United States are facing excessive heat advisories due to the third major "heat dome" event this month. Temperatures are expected to range from 95-105°F (35-40°C) from the Gulf Coast to the Great Plains and Midwest, with some desert areas potentially reaching 120°F (48°C). This prolonged heat, trapped by a high-pressure system, is expected to persist into the coming week. The article notes that while heatwaves are common, their increasing frequency and severity are linked to the human-caused climate crisis. Heat is identified as the deadliest weather phenomenon in the US, with vulnerable populations at higher risk due to elevated nighttime temperatures and high humidity.