A duck floats through floodwaters in Budapest's Obuda district on September 18.
Prime Minister Viktor Orban has called this flood wave one of the most significant challenges Hungary has faced.
Orban has warned that floodwaters will peak in Budapest on September 21, with the worst expected to pass by midweek after seven days of flood-prevention efforts.
Floodwaters inundated holiday homes in Gyor-Moson-Sopron, 130 kilometers from the capital, destroying homes and upending lives.
Nearly 10,000 workers and 15,000 volunteers are reinforcing flood defenses in Budapest.
A user-generated photo captures a runner under a bridge in Budapest.
"Hungary has learned flood protection during the previous floods, and professionals and volunteers know exactly what to do," Orban said.
A photo shows the elevated water levels along the Danube.
Flooding from Storm Boris, a slow-moving low-pressure system, has claimed at least 20 lives across the region.
The storm unleashed months' worth of rainfall in days, making it one of the worst storms to hit Europe in two decades.
Floodwaters enugulf the quay along the Danube with the parliament building in the background.
Budapest Mayor Gergely Karacsony announced that the city will use 1 million sandbags to fortify flood defenses.
A photo of Budapest’s 13th district reveals the widespread inundation.
Sandbags are placed at the entrance to a subway station at Budapest's Bathyany Square on September 19.
A floating dock is now inaccessible due to the rising water levels.
With the Danube River forecasted to rise to the highest levels in a decade, Hungary is bracing for a critical test of its flood defenses.