If you thought summer was warm in and out of the ocean, you'd be right.

Scientists believe a freak marine heatwave contributed to the hot temperatures felt over summer, and say it's something we probably won't see for another 30 years.

Climate scientist Jim Salinger told Kate Hawkesby the last time this occurred was in the summer of 1933.

"We had lots of these big fat high-pressure systems and nothing coming up from the southern oceans and of course the clear skies allowed the sunshine to do the rest and warm up the seas."

LISTEN ABOVE AS JIM SALINGER TALKS TO KATE HAWKESBY