U.S. Heat Domes Set to Merge, Trigger Widespread Heatwave Next Week

Forecasters have identified two separate heat domes forming over the United States that are expected to combine early next week. The merged system will create a sustained high‑pressure ridge, producing heat‑index values of 100‑110 °F (38‑43 °C) from the Gulf Coast northward to the Southern Great Lakes, affecting Texas, Louisiana, Mississippi, Alabama, Georgia, Florida, Arkansas, Tennessee, Kentucky and parts of the Midwest.

The persistent high‑pressure dome traps hot air and humidity, limiting cloud cover and precipitation. Gardeners are warned that the extreme heat will increase transpiration, stress shallow‑rooted plants, thin lawns and raise the risk of sunscald on trees and shrubs. Recommended actions include deep early‑morning watering, mulching, shade for containers and postponing fertilizer.

Health officials note that prolonged heat and humidity raise the risk of heat‑related illness, including heat stroke, which already accounts for hundreds of U.S. deaths each year. Residents are advised to stay hydrated, avoid strenuous outdoor activity during peak heat, and monitor local heat‑warning alerts.