Floodwaters in Paris are set to peak shortly with the River Seine rising 6m (20ft) above its normal level.
The world-famous Louvre and Orsay museums have been shut so staff can move priceless artworks to safety.
The number of dead in the floods has now risen to at least 14 - 10 in southern Germany and two each in France and Romania.
More downpours are forecast for the weekend across a band of central Europe from France to Ukraine.
Several towns in southern Germany have been devastated. Belgium, Austria, the Netherlands and Poland have also been affected.
Thousands of people have been forced from their homes.
French President Francois Hollande said the weather was a serious climate phenomenon and a global challenge.
He is to declare a state of natural disaster in the worst-hit areas, which will free up emergency funds.
Rail operator SNCF has closed a line that runs alongside the Seine in central Paris.
More than 5,000 people have been evacuated from towns in central France since the weekend and 19,000 homes are without power, the AFP news agency reports.
The French Open tennis tournament, meanwhile, could be forced to extend into a third week.
The world-famous Louvre and Orsay museums have been shut so staff can move priceless artworks to safety.
The number of dead in the floods has now risen to at least 14 - 10 in southern Germany and two each in France and Romania.
More downpours are forecast for the weekend across a band of central Europe from France to Ukraine.
Several towns in southern Germany have been devastated. Belgium, Austria, the Netherlands and Poland have also been affected.
Thousands of people have been forced from their homes.
French President Francois Hollande said the weather was a serious climate phenomenon and a global challenge.
He is to declare a state of natural disaster in the worst-hit areas, which will free up emergency funds.
Rail operator SNCF has closed a line that runs alongside the Seine in central Paris.
More than 5,000 people have been evacuated from towns in central France since the weekend and 19,000 homes are without power, the AFP news agency reports.
The French Open tennis tournament, meanwhile, could be forced to extend into a third week.
