A girl drinks water from a public fountain tap in Madrid, Spain

Video. Spain sweltering in third heatwave of the summer

Spain is sweltering in another heatwave that meteorologists warn could be the "most extreme of the summer" and has triggered widespread weather alerts.

Spain is sweltering in another heatwave that meteorologists warn could be the "most extreme of the summer" and has triggered widespread weather alerts.

Much of the southern part of the country was on orange alert on Tuesday with temperatures expected to surge above 40C in 25 of the country's 50 provincial capitals.

The meteorological agency also issued maximum red alerts for parts of Andalusia in the south, the Madrid region in the centre, and the Basque Country in the far north.

This latest heatwave, the third this summer, is expected to last until at least Friday but may extend into the weekend in some parts of the country.