Nuclear power plants in France and Switzerland were forced to shut down or reduce output between July 1 and 3, 2025, as a major heatwave raised river water temperatures above regulatory cooling thresholds.
At least eight people have died across Spain, France, and Italy as an early-summer heatwave swept across Europe in late June and early July 2025, breaking temperature records and prompting red alerts and emergency responses.
Sea surface temperatures in the western Mediterranean Sea reached up to 30 °C (86 °F) in early July 2025, with anomalies of 5–6 °C (9–10.8 °F) above average under strong to severe marine heatwave conditions.
Temperatures above 40 °C (104 °F) led to the closure of over 1 350 schools in France and work restrictions across 13 Italian regions between June 30 and July 2, 2025, as a persistent heat dome caused red-level alerts and severe public health risks across southern Europe.
Japan recorded its hottest June since records began in 1898, with average temperatures 2.34°C (4.21°F) above normal and over 200 locations registering highs of 35°C (95°F) or more, the Japan Meteorological Agency reported on June 30, 2025.
Two heat-related deaths were reported in Texas and Missouri between June 21 and 23, 2025, as a prolonged and intense heat wave driven by a persistent heat dome engulfed large parts of the central and eastern United States. Extreme heat will linger in the Ohio Valley through Friday, then we will finally see some relief from the heat this weekend.
A heat dome settled over the United States beginning June 23, 2025, driving record-breaking temperatures across the Northeast and Mid-Atlantic. More than 245 million people experienced daytime highs above 32 °C (90 °F), with 33 million facing extreme heat above 38 °C (100 °F) by June 24. Cities like New York and Philadelphia saw historic highs and record-warm nights, leading to heat advisories and health warnings across 2/3rd of the US states.
A heat dome that formed over the central and eastern United States on June 20, 2025, has triggered record-breaking temperatures and extreme heat warnings across several states. Daily highs are forecast to exceed 38°C (100°F) in multiple major cities through June 24.
A large heat dome is forecast to generate temperatures exceeding 38 °C (100 °F) across much of the central and eastern United States starting June 20, 2025, with high humidity compounding heat risks for over 200 million people.
At least four elderly women died of suspected heatstroke on June 17, 2025, in Japan’s Kanagawa, Shizuoka, Saitama, and Gunma Prefectures. More than 60 monitoring stations recorded temperatures at or above 35 °C (95°F). Temperatures are expected to rise until June 20, and a heat advisory is in place.
