The charitable event is in its 22nd year and is always celebrated on the weekend closest to the shortest day.
About 200 waterskiers, swimmers and spectators attended the afternoon social session, which this year was raising funds for the Mental Health Foundation.
The Wanaka area has received record falls of snow in the past week, creating a spectacularly snowy skyline around the lake.
Water temperature reports varied. Wanaka Lake Swimmers Club president Camille Gulick recorded 10.4degC, while Wanaka Waterski and Wakeboard Club organisers Graeme Vallance and Gary Tweedie recorded 12degC.
Mr Vallance and Mr Tweedie were delighted with the turnout and the sunshine.
"This is one out of the box ... the gods are with us and it is a great day," they said.
Jumping in a cold lake was "great therapy". "It is good for your mental health," Mr Tweedie said.
"The lake is warm," Mr Vallance insisted.
