Overview
- National Weather Service alerts now cover tens of millions of people with more than 74 million under heat alerts and about 47 million in the Midwest and Ohio Valley under extreme heat warnings.
- Forecasts call for consecutive days of mid‑90s to low‑100s highs and heat‑index values near 105–115°F that are expected to peak around the July 4 holiday weekend, with limited overnight cooling.
- Cities and counties have opened cooling centers, canceled or adjusted outdoor events and launched outreach to vulnerable and unhoused residents to reduce heat‑illness risk.
- Officials warn the prolonged heat and high humidity could boost emergency room visits, push electricity demand toward record levels and challenge water and cooling infrastructure.
- In the UK the Met Office says rain will return to northern and western areas this week but that high pressure could rebuild from the weekend, raising the likelihood of another multi‑day warm spell in southern England.