Milan has registered the highest average daily temperature for the past 260 years, regional environmental protection agency (ARPA) said Friday, as much of Italy grapples with a heatwave.

The Milano Brera weather station recorded an average 33 degrees Celsius (91.4 degrees Fahrenheit) on Wednesday, the highest since it started registering temperatures in 1763.

The northern Italian city's previous record, of 32.8 degrees, was set in 2003.

Milan also recorded the highest minimum temperature on Thursday at 28.9 degrees Celcius, ARPA said.

ARPA said the Italian Alps have also been hit by "intense and abnormal" temperatures, but said the heatwave is about to break, with heavy thunderstorms expected in the next few days.

Emissions of greenhouse gases are enabling increasingly intense and long-lasting heatwaves, especially in Europe, which the World Meteorological Organization (WMO) says is the world's fastest warming continent.

Heatwaves are among the deadliest natural hazards, with hundreds of thousands of people dying from preventable heat-related causes each year.