BUDAPEST — Surging Danube and Tisza floodwaters drove more than 38,000 people from their homes across Hungary, Slovakia and northern Serbia on Saturday, as a week of Alpine snowmelt combined with the heaviest late-April rains in decades to push river gauges to near-record highs and force the closure of bridges, rail lines and several stretches of the busy Vienna-Bucharest motorway corridor.

The Hungarian Disaster Management Directorate said it had ordered mandatory evacuations from 27 settlements along a 240-kilometer stretch of the middle Danube, with the largest movements at Gyor, Komarom and the northern suburbs of Budapest. Officials said the Danube at Budapest crossed 840 centimeters early Saturday morning, within two centimeters of the all-time record set during the 2013 flood, and was projected to crest above 850 centimeters by Monday afternoon as the wave moved downstream toward the Hungarian-Serbian border.

“We are in the second-most-serious flood emergency this country has faced in modern history, and the peak is still ahead of us,” Hungarian Interior Minister Sandor Pintér told reporters at a televised briefing in Budapest. “Every available soldier, every available volunteer, every available sandbag is now being deployed.”

Slovak Prime Minister Eva Smolková declared a state of emergency for the Bratislava region and four surrounding districts on Friday night after the Morava and Vah tributaries overtopped levees in three locations. Slovak military engineers, working alongside Czech and Austrian crews under a regional mutual-aid pact, were racing to reinforce a five-kilometer dike system protecting the industrial zone east of Bratislava, which houses one of Volkswagen Group’s largest European assembly plants. Production at the plant was suspended on Saturday morning.

In northern Serbia, where the Tisza joins the Danube near Titel, Vojvodina provincial authorities reported the evacuation of roughly 9,400 residents from low-lying villages and the deployment of 3,200 troops from the Serbian Armed Forces. Serbian President Aleksandar Vučić, visiting the town of Novi Becej, said the government had requested European Union Civil Protection Mechanism assistance and that helicopters from Romania, Greece and Italy were expected to begin arriving by Sunday.

At least 11 deaths had been confirmed across the three countries by Saturday evening, according to a tally compiled from national disaster agencies, including six in Hungary, three in Slovakia and two in Serbia. Most of the dead were elderly residents who refused or were unable to evacuate, officials said. A Slovak firefighter was among the fatalities, swept into a swollen culvert during a rescue attempt in the village of Devínska Nová Ves.

The flooding marks the most severe Central European hydrological event since the catastrophic summer floods of 2024, and arrives unusually early in the year. Meteorologists with the Vienna-based European Centre for Medium-Range Weather Forecasts said an unusual blocking pattern over Scandinavia had funneled a series of moisture-laden Atlantic systems into the Alps over a 10-day period, dropping 180 to 240 millimeters of rain on terrain still covered in deeper-than-average late-season snowpack.

“You very rarely see this combination — a thick snowpack still holding into the third week of April, then four atmospheric river events stacked back-to-back over the high catchments,” said Dr. Anneliese Brunner, a hydrologist at the Federal Office of Meteorology and Climatology in Zurich. “The result is that water that would normally be released into the rivers over six to eight weeks is reaching the lowlands in seven days. The system is simply not designed for that compression.”

Brunner and other researchers noted that warmer winters had pushed Alpine snowpack accumulation later into the season, while warmer springs had compressed the melt window — a combination that European climate adaptation agencies have flagged in repeated reports as a rising risk for the Danube and Rhine basins. A joint statement from the International Commission for the Protection of the Danube River said member states would convene an emergency hydrology board in Vienna on Tuesday.

Economic damage estimates were preliminary, but Munich Re analyst Klaus Reinholt told the Frankfurter Allgemeine Zeitung that insured losses across the three countries could “easily exceed three billion euros” if the projected crest held. River shipping on the Danube — a key corridor for Romanian and Bulgarian grain bound for Western Europe — was suspended along nearly its entire navigable length above the Iron Gates. Grain traders in Constanta said the disruption was unlikely to materially affect global wheat or corn benchmarks but would tighten Central European feed-grain logistics for several weeks.

In Budapest, where sandbag walls had been built along the embankments of Pest from Margaret Bridge south to the Rákóczi Bridge, the mood was a familiar mixture of vigilance and exhaustion. Volunteers, many of them university students, filled and stacked sandbags through the night beneath portable floodlights. Mayor Gergely Karácsony said the city had distributed more than 1.4 million sandbags in 72 hours and was importing additional sand from quarries in eastern Hungary.

“We have done this before. We will do it again. But we cannot keep doing it every two or three years,” Karácsony said in a video address. “This city was not built to live behind a wall.”

In Komarom, on the Slovak-Hungarian border, residents of a mobile-home community along the riverbank described being woken before dawn by police officers banging on doors. “The water was already across the road by the time we got out,” said Margit Tóth, 71, who was sheltering in a school gymnasium with her two cats. “I have lived here forty-two years. The river has never come up so fast in April. Never.”

Forecasters at the European Flood Awareness System said the Danube wave would continue downstream into Croatia and Romania through the first week of May, and warned that secondary tributary flooding in Bosnia and northern Bulgaria remained possible if a weaker rain system forecast for Wednesday materialized. EU Commissioner for Crisis Management Janez Lenarčič said Brussels would activate emergency cohesion funds and expected a formal damage assessment mission to deploy within 10 days.

Hungarian officials said additional evacuation orders, including possible expansions in southern Pest County, would be issued as river forecasts updated through the weekend.