Plymouth's new £46.5m Life Centre will open in February 2012 after freezing winter weather caused delays.
The leisure centre with Olympic-sized swimming pool had been due to open this autumn.
Plymouth City Council is blaming the weather and a water pipe which had to be moved.
It said that the delay was "what you would expect in a project of this scale and everyone is very pleased about how the work has progressed".
Builders Balfour Beatty will hand over the building to Sports and Leisure Management (SLM) after Christmas.
SLM will install equipment, carry out safety checks and train staff for opening in February 2012.
Canada's diving team and the Lithuanian swimming team have chosen the Life Centre for their pre-Olympic Games training camps.