49°C Temperatures, 40 Million Under Alert: How A Giant Heat Dome Is Scorching US

Heatwave In US: At least 40 million people across the United States are under extreme heat warnings as a powerful heat dome pushed temperatures to dangerous levels, with parts of the Southwest forecast to reach 49°C (120°F). The scorching conditions have prompted health alerts, disrupted outdoor events and raised concerns over heat-related illnesses.

Here’s what’s happening:

1. More Than 40 Million People Under Heat Alerts

Extreme heat warnings stretch across large parts of the central and southern US, affecting states from Minnesota to Mississippi and extending west into Nevada and Southern California. Heat index values- which combine temperature and humidity- have climbed well above 38°C (100°F) in several areas.

2. Temperatures Could Reach A

Blistering 49°C

The US National Weather Service warned that parts of the Southwest could see temperatures as high as 49°C (120°F). On Saturday, Rapid City, South Dakota, recorded an all-time high of 44°C (112°F), while extreme heat forced the cancellation of a horse race in Minnesota.

3. A Giant ‘Heat Dome’ Driving Extreme Weather

Meteorologists said that the unusually intense heat is being caused by a heat dome- a high-pressure system that traps hot air near the ground, allowing temperatures to build day after day with little relief. The phenomenon is also locking in high humidity, making conditions feel even hotter.

4. Heat Bringing More Than Just High Temperatures

The weather system is also increasing the risk of severe thunderstorms, flash flooding and hail, particularly around the Great Lakes. Forecasters said that the unstable weather is linked to moisture circulating around the edges of the heat dome and could shift east in the coming days.

5. Health Risks Remain High

Authorities urged residents- especially older adults, children and people with underlying medical conditions- to stay hydrated, avoid prolonged exposure to the sun and seek air-conditioned spaces.

Forecasters expect some relief in parts of the central US by the middle of the week, although temperatures could climb again by next weekend as the heat dome shifts across the country.