Torrential downpours early Thursday caused havoc with the Olympic programmes as several events started late or had to be postponed.
The qualification for the women's high jump and the men's javelin had to be delayed by an hour while the long jump and shot-put events of the decathlon were also delayed.
Cycling's ruling body, UCI, meanwhile, said that the BMX semi-final and final runs, which were scheduled for Thursday, had been postponed for a day.
They said it would be too dangerous to hold the events in such wet conditions, the dpa reported.