Portugal has recorded 284 deaths during the ongoing heatwave, the country's Directorate-General for Health (DGS) has said.
According to preliminary data from the DGS, more than 70% of the deaths, which occurred between 28 June and early July, were among people aged over 85.
There is a potential risk that this number could climb further, with high-temperature risks predicted in the Alentejo region.
The Portuguese Institute for Sea and Atmosphere has indicated that the current heatwave is expected to last until at least mid-week.
Maximum temperatures could reach 40 degrees Celsius in the Douro and Tagus valleys, it warned.
This comes after mainland Portugal recorded its hottest ever temperature in late June, when 46.6 degrees Celsius was logged in Mora, which lies around 100 kilometres east of the capital Lisbon.
Meanwhile, authorities in neighbouring Spain have placed more than 18,000 residents in the north-eastern Tarragona province in lockdown as a wildfire continues to burn.
Large parts of Spain are on high alert for wildfires after the country experienced its hottest June on record.
Two people died in a fire on 1 July in the region of Catalonia, where Tarragona is located.
This latest blaze started in the early hours of Monday in a remote area near the village of Pauls, where strong winds and rugged terrain have hampered firefighting efforts, authorities said.
An emergency military unit was deployed early on Tuesday to help the more than 300 firefighters working in the area.
"Since midnight, firefighters have been battling the blaze with gusts of wind reaching up to 90 kilometres per hour," Catalonia's regional firefighting service said, adding that strong winds were expected to ease by Tuesday afternoon.
Red alerts in France
France is also attempting to put out wildfires.
At least 10 people — five civilians and five firefighters — have been injured in a blaze in the southern prefecture of Aude, which led to the partial closure of the A9 motorway.
The road reopened on Tuesday morning but the fire "continues to spread," warned Colonel Christophe Magny, the director of the Aude fire service.
The fire, which broke out on Monday at around 3 pm, is thought to have been started by "a cigarette butt thrown from a vehicle", according to Magny.
Elsewhere, flights have been suspended at Marseille Airport because of a wildfire that is raging close to the southern French port city, local authorities said Tuesday.
The prefecture told residents in the affected areas to stay indoors and off the roads.
The French weather service Météo France said a further two departments — Var and Vaucluse — are also on red alert for possible forest fires.
Hungary suffers from sudden shift in weather
In Hungary, Monday's storm caused massive damage: the wind uprooted trees, downed power lines, paralysed rail traffic, and left 150,000 households without electricity.
The wind blew off the roof of a building at the University of Szeged, and the tower of the church in Sápi collapsed.
The storm caused further damage to the railway infrastructure on Tuesday. Hungarian Minister of Construction and Transport János Lázár stated in a video that his ministry cannot guarantee the resumption of traffic on all lines today, as the repair work from yesterday's storm damage continued throughout the night.
"Primarily, colleagues worked on freeing the main lines," said Lázár, who noted that it may take days if not weeks to restore traffic on electrified tracks.
"We are struggling with huge problems and challenges on the Balatonfüred line and direction. But fortunately, Volán has so much bus capacity that several hundred buses complement the incomplete and difficult-to-use line network," he added.
Following strong winds and heavy rainfall on Tuesday, the mercury is expected to drop even further on Wednesday, with an average daily temperature of 15 degrees in the capital.
"On Wednesday morning, we may feel like we're in late autumn, with winds of 60–70 km/h or more heavy rain, while the temperature will feel close to 10 degrees," meteorologist László Molnár told domestic outlets.
HungaroMet highlights that "on Tuesday afternoon, due to the storm system in the eastern border region, there is a renewed chance of damaging wind gusts above 90–110 km/h developing in a larger area."
From fires to storms
Meanwhile, a severe hailstorm ripped up trees and tore off roofs when it hit the Croatian port of Split on Tuesday morning.
High winds and hail damaged the roof of the city's football stadium and caused a ferry to slip its moorings at the port. The boat then hit two other vessels, one of which sank.
At least three people were injured in the storm, and material damage across the city was significant. Photos carried by Croatian media showed downed trees and flooded streets.
This happened as hundreds of fires raged in neighbouring Serbia following a period of extremely hot weather across parts of the Balkan region. So far they have injured six people.
Serbian firefighters battled more than 600 wildfires on Monday.
At least three municipalities in southern parts of the country have declared emergency measures due to the fires.
"Many villages were jeopardised. We have a number of burnt and damaged properties but we have managed to save many too," senior emergency official Nedeljko Gagić told public broadcaster RTS.
The country has been hit by a severe drought this summer, which has endangered crops and led to restrictions in supplies of drinking water.
Experts say that the extreme weather conditions currently gripping Europe can be linked to climate change.
