Heat waves trigger extreme weather across multiple countries

Heat waves have hit multiple countries, triggering extreme temperatures, wildfires, flooding and widespread emergency responses.

In Portugal, authorities have issued the highest level red weather warnings from Thursday through at least Saturday across 12 of 18 mainland districts, including the capital Lisbon, as an extreme heat wave could push temperatures toward 47 degrees Celsius in the coming days. The remaining districts are under orange alert.

The government has urged the public to exercise maximum caution and avoid risky behavior, calling for a ban on activities that could ignite fires, including agricultural and open-air burning, barbecues, and the use of machinery capable of generating sparks.

Cities have opened selected metro stations overnight to provide cooling shelter for homeless residents, while temporary air-conditioned shelters are also being prepared for vulnerable groups. Emergency services have raised their readiness level in anticipation of a significant rise in rural wildfire risk.

Further north in England, record-breaking warmth made June the hottest since records began in 1884, with an average temperature of 17.1 degrees Celsius compared to 16.9 degrees Celsius in June 2025.

"The exceptional warmth was driven by an intense and record-breaking heatwave at the end of the month," the UK's weather agency Met Office said on Wednesday.

The UK as a whole experienced its second-warmest June on record with unusually high overnight temperatures, which has disrupted the transport systems, schools and hospitals.

Climate experts have urged the government to adapt its infrastructure to warming summers, with a surge in demand for fans and air conditioners, which remain rare in British homes.

"June's high temperatures are part of a broader pattern of warmth during 2026," said Met Office scientist Emily Carlisle, pointing out that the UK had experienced above average temperatures every month this year except for January.

At the same time, France battled a large wildfire in its south on Wednesday. In the Herault and Aude departments, hundreds of firefighters mobilized to contain blazes fueled by drought and strong winds, which burned about 800 hectares by late evening. Difficult terrain and dry vegetation hampered containment efforts, forcing evacuations and confining residents in several communes, while water-bombing aircraft assisted ground crews. Two smaller fires also broke out near Marseille, according to local firefighters.

Across the Atlantic, extreme weather is affecting Canada, where a "heat dome" has triggered persistent high temperatures across multiple provinces, including Ontario, Quebec, the Prairies and the Northwest Territories. As daytime highs and humidity values have climbed well above seasonal norms, millions are under heat alerts. Officials have urged residents to stay hydrated, avoid strenuous outdoor activities during peak afternoon hours, and check regularly on vulnerable groups. 

The combination of sweltering heat and unstable atmospheric conditions has increased the risk of severe thunderstorms and associated secondary disasters in parts of the country, including disruptions in Ottawa during Canada Day celebrations on Wednesday. In contrast to the scorching heat, the Parkland region of Manitoba in central Canada has been hit by torrential rain, causing severe flooding. The city of Dauphin in western Manitoba declared a local state of emergency on Wednesday to cope with the rapidly worsening flood situation.

Emma Howard Boyd, chair of the National Heat Risk Commission at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science, told France 24 that Europe's recurring heat waves are no longer exceptional weather events but evidence of a structural climatic transformation.

She added that the continent has entered an era in which extreme heat should be understood as a systemic national risk rather than a seasonal inconvenience, with rising temperatures unfolding largely as predicted and heat waves becoming both more frequent and longer-lasting.

(With input from agencies)