EditEarly summer heatwave chokes populations from the Danube to the Balkans
Energy systems are buckling under surging demand with solar delvering its strongest performance yet
Europe’s summer has arrived not with a breeze, but with a blaze. From the drought-stricken Danube to blackouts narrowly avoided in Germany and France, early July has laid bare the continent’s increasing vulnerability to heat, water stress, and an overstretched energy system.
In Hungary, the mighty Danube is flowing at a trickle. River levels are so low that cargo ships can carry just 30 to 40 percent of their usual loads, with shipping companies forced to absorb surcharges of up to 100%. “These levels are what we usually see in late August, not early July,” said Attila Bencsik of the Hungarian Shipping Association. Meteorologists point to an astonishing lack of rainfall – just 17% of the monthly average fell in June, making it the driest since 1901.
Ecosystems at risk
Further downstream, the Danube near Oryahovo in Bulgaria is too shallow for ferries to operate. The water level has dipped below the operational threshold, and authorities have no clear forecast on when crossings to Romania can resume.
Meanwhile, in the Srebarna Nature Reserve, a UNESCO biosphere, emergency action is underway to rescue a vanishing wetland ecosystem. The Ministry of Environment and Water has deployed industrial pumps to divert Danube water into the reserve’s lake, where levels are nearly a meter below the biological minimum. Coordination between civil protection forces, local government and the fire service is ongoing, with reinforced paths and channels prepared to sustain the delicate habitat.
The last time Srebarna received a full recharge from the Danube was in spring 2023. Since then, hydrological isolation has deepened, with broader climatic and structural factors at play: fewer snowfalls upstream, earlier melts, retention by hydroelectric reservoirs, and rising regional water consumption.
The Balkans: fields dry, hydropower struggles, pools close
The heat has hit the western Balkans hard. In Albania, central regions recorded 40°C on 3 July, and the Meteorological Institute warns that meaningful rain may not return before September. Rivers have nearly vanished after a dry winter and spring, pushing the government to activate large-scale irrigation from the Mat River to protect 4,000 hectares of farmland.
Albania’s reliance on hydroelectricity has backfired. With dams running dry, the National Energy Corporation has spent €60 million importing electricity in just the first half of 2025.
Serbia’s State Meteorological Institute has declared an “extreme drought,” warning of severe crop losses and declining water tables in rivers and lakes. In some towns, drinking water rationing has already begun.
Kosovo faced a symbolic blow: Pristina’s largest outdoor pool, built in the 1980s and nestled in the natural mineral water park of Gërmia, remains empty. “In previous years, it took six days to fill. Now, even three weeks might not be enough,” said pool manager Bard Krasniqi. The water supply has dried up, halting operations and denying locals a refuge from the 35°C heat.
Crete evacuates as flames threaten tourist hubs
As much of Europe reeled under record temperatures and water stress, Greece faced a flare-up of another kind. A wildfire on the island of Crete forced the evacuation of 5,000 people, including around 3,000 tourists, from hotels and homes near the resort town of Ierapetra on 2 July.
Firefighting efforts continued on Thursday, with 230 firefighters and six helicopters deployed. “The fire is receding,” said fire brigade spokesperson Vassilios Vathrakogiannis, adding that while flare-ups remained possible, there was no longer an active front.
Another fire, driven by strong winds near the port of Rafina east of Athens, was brought under control on 3 July. Though the blaze destroyed several homes and vehicles and forced 300 evacuations, fire crews remain on alert due to its proximity to Athens International Airport.
Ferry traffic to tourist islands in the western Aegean, including Mykonos, was disrupted.
So far, Greece has been spared the brunt of the searing heatwave that gripped countries like Spain and France. But that may change soon: forecasters warn of temperatures reaching 43°C in some parts of the country this weekend. With heat and drought returning, the threat of devastating wildfires looms once more – a grim pattern now repeating yearly.
Electricity demand spikes, nuclear reactors strain
With temperatures climbing above 40°C in parts of Spain and Germany, and averaging 34-35°C across France and Central Europe, energy systems are buckling under surging demand. Between 28 June and 2 July, power consumption rose by up to 14% in Spain, 9% in France, and 6% in Germany – a spike directly linked to increased use of air conditioning.
But as power demand soared, generation faltered. In France, 17 of the country’s 18 nuclear reactors suffered reduced output or temporary shutdowns as high river temperatures disrupted cooling processes. Poland, Germany, and other nations reported similar strain across thermal generation.
Solar saves the daylight – but not the night
Yet amid the heat, solar energy delivered its strongest performance yet. According to Ember, an energy think-tank, June 2025 marked the highest solar generation month in EU history – up 22% from 2024. On the hottest days, Germany alone produced 50 GW during peak sun hours.
“Solar saved us from major blackouts,” said Ember’s Europe Programme Director Pawel Czyzak. “But the grid’s weakness comes after sunset.”
Without sufficient battery storage or flexible demand systems, the evening hours turned costly. Between 24 June and 1 July, electricity prices rose 175% in Germany, 108% in France, and over €470/MWh was recorded in Poland during the evening peak on 1 July. While interconnectors helped redistribute supply, Ember warns that resilience remains fragile.
“Heatwaves will not go away, they will only get more severe in the future. Solutions that can help mitigate their impacts, such as battery storage, interconnection, demand flexibility and dynamic tariffs, should become a key part of grid planning and power market design. Perhaps the biggest opportunity is to store solar electricity, to help power air conditioning well into the evening,” said Czyzak.
Sources: Reuters, BGNES
Caption: This picture, taken by a drone, shows the sandbanks of the River Danube near the island peak of Kisoroszi, due to the low water level in Kisoroszi, Hungary, 03 July 2025. The water level of River Danube is unusually low due to a long droughty period. EPA/PETER LAKATOS
Updated: July 4, 2025 - 13:53
