A severe heatwave struck North America starting in late June 2026, bringing record-breaking temperatures and extreme conditions to both the United States and Canada. The first heat dome over the eastern regions peaked on July 4 with 106°F (41°C) in Atlantic City, while in Canada it triggered massive thunderstorms, flooding, and power outages—including 100,000 Hydro-Québec customers losing electricity—on Canada Day. A second heat dome then formed over the west, setting records in Manitoba, British Columbia (Lytton at 41.2°C), and even Nunavut, while Ontario recorded its highest temperature since 1936 (Armstrong at 40.7°C). In the US, July 2026 became the hottest month on record (average 76.89°F), with 180 million people under heat risk, and the heatwave coincided with the FIFA World Cup, Independence Day, and Canada Day, forcing participants to take extra precautions. As of August 5, 2026, at least 70 deaths have been attributed to the heatwave, which scientists link to a developing El Niño and human-caused climate change. The extreme heat strained public services like transit and power grids, leaving hundreds of thousands of homes without electricity at various points.