Temperatures are forecast to be between 5C to 10C above seasonal norms, with Spain's Aemet weather agency warning it was "likely that the heatwave lasts long and persists till at least next Sunday".

More than 1,300 firefighters backed up by a dozen waterbombing planes battled three big wildfires in central and northern Portugal on Tuesday, with authorities putting most of the country on red alert for fires after weeks of hot weather.