Niwa principal scientist Chris Brandolino said temperatures across the country were set to be above average through to Christmas, when conditions looked to become more settled.
Prendergast said feedback from growers in the Hawke's Bay and Central Otago was that stone fruit crops were looking good on the trees.
But, conditions such as too much rain could affect the likes of cherries and strawberries that are particularly susceptible to adverse weather.
Despite the availability of good quality strawberries in supermarkets already, Prendergast said it was too soon to tell what supply would be like at Christmas.
He was hoping that the weather would hold up.
Countdown merchandise manager of produce Steve Sexton said in the weeks leading up to Christmas, strawberries become the number one product sold in its supermarkets.
"We sell the equivalent of nearly 70 rugby fields of strawberries at Christmas."
Sexton said Countdown was expecting a plentiful supply of stone fruit and berries including cherries, blueberries and raspberries for Christmas.
He said prices were heavily driven by supply and demand, but he anticipated prices would be similar to last year.
A Foodstuffs spokeswoman said the supermarket chain was also looking forward to a great season of stone fruit as long as the weather cooperates. Foodstuffs also expected volumes of raspberries, blackberries and blueberries to increase as we head into Christmas.
Prendergast said raspberries were going to be particularly good this year as a lot of the crops were grown undercover, making them easier to control and less prone to weather problems.
He did, however, say early season apricots were expected to be in slightly short supply at the beginning of December, which has been the trend for the last few years. That was set to change once we start hitting the peak of the season at Christmas.