Gigantic forest fires have regularly raged through the vast expanses of Russia's Siberia, but the magnitude of this year's blazes has reached an exceptional level with fears of a long-term impact on the environment.

As fires sweep across millions of hectares enveloping entire cities in black smoke and noxious fumes, environmentalists warn of a disaster threatening to accelerate the melting of the Arctic. 

Freak storms and flash flooding following last week's heatwave in Italy claimed three lives this weekend, including a young woman caught up in a mini-tornado near Rome's Fiumicino airport.

Belgian meteorologists registered a record high temperature for the country on Thursday when western Europe sweltered under a heatwave that has severely disrupted transport.

Poor forest management and firefighting techniques make Portugal especially vulnerable to wildfires as climate change makes hotter, longer summers more likely, experts warned as the latest blazes struck this week.

Hot, hotter, hottest! Paris, London and places across Europe are bracing for record temperatures Thursday as the second heat wave this summer bakes the continent.

Climate scientists warn this could become the new normal in many parts of the world. But temperate Europe — where air conditioning is rare — isn't equipped for the temperatures frying the region this week.

Greenpeace activists on Wednesday briefly blocked incoming British prime minister Boris Johnson's convoy as it made its way to Buckingham Palace, urging him to take action on climate change.

The southwestern French city of Bordeaux saw its highest ever temperature since records began of 41.2 degrees Celsius (106.16 Fahrenheit) Tuesday,  weather service Meteo-France said.

France and western Europe were Tuesday bracing for a new record-breaking heatwave that is forcing the temporary shutdown of a French nuclear power station and will test competitors in the legendary Tour de France cycle race.

Parisians were on Monday bracing for potentially the hottest ever temperature in the French capital this week as a new heatwave blasted into northern Europe that could set records in several countries.

Americans braced for a second -- and equally scorching -- day of dangerously hot weather Sunday, with daytime temperatures forecast to approach 100 degrees Fahrenheit (38 degrees Celsius) across a number of major US cities.