Archive · 27 Jul 2026
Dangerous heat wave, storms, floods hit multiple US states
The United States is experiencing extreme weather conditions.
A heat dome is causing very high temperatures in the central and southern states, making it dangerous for people and infrastructure.
At the same time, severe thunderstorms are expected in the Upper Midwest and Northeast, bringing damaging winds, hail, and heavy rainfall.
The Southwest is also getting a lot of rain from the North American monsoon, which can cause flash flooding.
People in these areas are advised to stay indoors during the hottest parts of the day, drink plenty of water, and monitor weather alerts for severe storms and floods.
A dangerous combination of extreme heat, severe thunderstorms, and flash flooding is affecting much of the United States through July 29.
A heat dome is causing prolonged high temperatures in the central and southern US, with daytime temperatures reaching the upper 90s to low 100s°F (37°C-40°C).
Severe thunderstorms are expected in the Upper Midwest and Northeast, bringing damaging winds, hail, and heavy rainfall.
The North American monsoon is bringing heavy rainfall and thunderstorms to the Southwest, increasing the risk of flash flooding.
Residents in affected areas are advised to stay indoors during the hottest parts of the day, drink plenty of water, and monitor weather alerts.
- Who
- Residents of multiple US states, including Texas, Oklahoma, Minnesota, Wisconsin, Michigan, and others
- What
- Dangerous heat wave, severe thunderstorms, and flash flooding
- When
- Through July 29
- Where
- Central and southern US, Upper Midwest, Northeast, Southwest
- Why
- Due to a broad upper-level high-pressure ridge (heat dome) and interactions with warm, humid air from the Gulf of Mexico, as well as the North American monsoon
Heat Dome Impact
Storm Systems
Causes of Extreme Weather
Heat Dome Impact
A broad upper-level high-pressure ridge, or heat dome, is causing extreme heat by trapping hot air and preventing cooling.
Storm Systems
Disturbances along the northern edge of the ridge are colliding with warm, humid air, creating severe thunderstorms.
- Affected States (Heat Wave)
- Texas, Oklahoma, Kansas, Nebraska, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Tennessee, Southern Rockies, Desert Southwest
- Affected States (Severe Thunderstorms)
- Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio
- Affected States (Flash Flooding)
- Michigan, Ohio, Pennsylvania, New York, Vermont, New Hampshire, Massachusetts, Connecticut, Rhode Island, New Jersey
- Expected Temperatures
- Upper 90s to low 100s°F (37°C-40°C) in the Plains and Southeast, 115°F to 120°F (46°C-49°C) in isolated parts of the Desert Southwest
- Heat Index Values
- Exceeding 105°F to 115°F (40°C-46°C)
- Overnight Temperatures
- Remaining in the 70s°F in many locations
- Severe Weather Risks
- Damaging winds, large hail, frequent lightning, heavy rainfall, flash flooding
- Monsoon Affected Areas
- Arizona, New Mexico, Utah, Colorado, Parts of Wyoming, the central and northern Rockies, the High Plains