Heatwave Grips California Amid Storm and Flood Alerts in Central, Southern US

The United States is bracing for a day of contrasting weather extremes on Tuesday, June 23, 2026. While California and parts of the West are under an intense heatwave, numerous states in the central and southern regions are facing alerts for severe storms, heavy rainfall, and flash floods that could persist throughout the week.

“

California will be one of the states most affected by the intense heatwave that will settle over the western United States starting this Tuesday.

California is particularly affected by a powerful high-pressure system settling over the West Coast, leading to a significant temperature rise. Over 10 million people across the state, including all residents in the Los Angeles metropolitan area, are under an extreme heat watch effective from Tuesday morning through Thursday night. Forecasts suggest a "heat dome" will trap warm air, pushing temperatures above 100°F (38°C) in some areas. Los Angeles, Hollywood, and Beverly Hills could see highs near 90°F (32°C).

“

More than 10 million residents in California are under extreme heat watch until Thursday night.

Meanwhile, a weather system stretching from the Northeast to the Plains is interacting with a humid and unstable air mass. This is expected to trigger rain and thunderstorms across several states. The National Weather Service (NWS) has identified two primary areas at risk for flash flooding: the Mid-Atlantic region, from the Delmarva Peninsula to the Carolinas, and a stretch from the middle Mississippi River Valley to the High Plains.

“

The "heat dome" will trap warm air near the surface and push it inland, allowing temperatures to exceed 100°F (38°C) in some sectors.

As the week progresses, a cold front moving toward the East Coast may lessen storm activity there. However, unstable conditions are forecast to continue in the Plains, with the potential for large storm systems to organize. This pattern is expected to impact the central U.S. and the Upper Midwest over the next two days. The Storm Prediction Center (SPC) has warned of potential hazards including large hail, intense wind gusts, and isolated tornadoes.

“

An extensive front stretching from the Northeast to the High Plains will interact with a very humid and unstable air mass, favoring the development of rain and thunderstorms.