The highest temperature in European history appears to have been recorded in Italy during a heatwave sweeping the country, with early reports suggesting a high of 48.8C (119.85F).

If this is accepted by the World Meteorological Organisation it will break the previous European record of 48C (118.4F) set in Athens in 1977. The temperature was measured at a monitoring station in Syracuse, Sicily, and confirmed soon after by the island’s meteorological authorities.

The finding comes amid a fierce heatwave stretching across the Mediterranean to Tunisia and Algeria. Fires have blazed across much of the region for more than a week. Italy’s government has declared a state of emergency. Turkey and Greece have also been hit by devastating conflagrations.

Trevor Mitchell, a meteorologist from the UK Met Office, said: “The Società Meteorologica Italiana say that the temperature report of 48.8C is genuine. However, with potential records such as these there is typically a process of verification before they can be declared officially.

“Sicily has been experiencing a heatwave in the last few days. The foehn effect [a change from wet, cold conditions on one side of a mountain to warmer, drier conditions on the other] in the lee of the mountains to the west of Syracuse is likely to have assisted in generating the 48.8C observed there today.”

Scott Duncan, a Scottish meteorologist, said more heat records were inevitable. “A dangerous heatwave spanning much of north Africa and into southern Europe is unfolding right now. The focus of heat will shift west and north slightly in the coming days,” he tweeted.

The extreme heat in Europe is the latest unwelcome record to strike the northern hemisphere this summer. Temperature records have been smashed in Canada, the west of the US, Finland, Estonia, Turkey and Moscow. Unprecedented floods have swept through Germany and parts of China. Record wildfires are blazing in the Siberian taiga, the world’s biggest forest.

In Russia’s Sakha republic forest fires have released 208 megatonnes of carbon this year, almost double last year’s record, according to Mark Parrington, a senior scientist with the Copernicus Atmosphere Monitoring Service.

Climate scientists have long predicted that fossil fuel emissions from vehicles, factories and deforestation would lead to more extreme weather. The latest report by the UN’s Intergovernmental Panel on Climate Change, released on Monday, said the link was unequivocal and irreversible but that worse impacts could be reduced if governments acted quickly.

“This is climate change in 3D. It is here,” said Owen Gaffney, an analyst at the Potsdam Institute for Climate Impact Research. “We are radically changing the climate system so hot areas will get hotter, wet areas will get wetter. We are going to get more extremes.”

Friederike Otto, an associate director of the Environmental Change Institute at Oxford University, said extreme weather, and particularly extreme heat, was being seen across the world. “Climate change is already here. There are things we can stop from getting worse, but there are a lot of changes that are already here.”