Unexploded World War II-era bombs forced some 90,000 people to leave their homes in the German city of Koblenz and the country's banking capital Frankfurt.
The ongoing evacuation of some 70,000 people in Frankfurt on Saturday was the largest operation of its kind in post-war Germany.
On Sunday, a 1.8-ton HC 4000 bomb packed with 1300 kilograms of explosives will be defused in the densely populated upmarket Westend neighbourhood in Frankfurt.
The "blockbuster" bomb was dropped by Britain's Royal Air Force (RAF) pilots during World War II.
Police in Frankfurt handed out flyers to remind residents once more to evacuate and asked neighbours to reach out to anyone who may not have gotten the messages.
Emergency services also advised residents to leave their homes in the same condition they would before holiday.
Police planned to bulk up patrols on Saturday to ensure that thieves and other criminals would not take advantage of the empty residences.
Meanwhile, ordnance experts defused an unexploded World War II-era aerial bomb in the Karthause section of Koblenz on Saturday.
The 21,000 residents who lived within the bomb's 1-kilometre radius were allowed to return after a large-scale evacuation operation.
The operation was slightly delayed after several people in the affected area would leave their homes only after intensive talks, and there were two cases were residences were forcefully evacuated.
A prison, two train stations, a hospital and a senior home all had to be evacuated in the days leading to Saturday.
The 500-kilogram aerial bomb was found on Monday during construction for a new kindergarten.
Experts estimate that close to a quarter of a million bombs dropped on Germany by the Allied Forces during World War II did not explode due to technical faults.
