Even in areas that are mapped, like the Camp Mystic site in Kerr County, Texas, that was hit by a deadly flash flood on July 4, 2025, the maps may underestimate their risk because of a reliance on historic data and outdated risk assessments.

High humidity levels, summer heat and long days will combine to produce conditions favorable for drenching thunderstorms leading to additional flash flooding in the coming days in many parts of the U.

NYC could be in play for another heat wave this week, with the potential for more heavy rain, storms and flash flooding due to the hot and humid conditions.