No but they are available in winter.
Harvest is in the Fall
It’s understandable to think that cranberries could be a winter fruit because we often see them available at that time to make cranberry sauce and other delicious recipes for our Christmas turkey.
We also see them in stores sold fresh and frozen in the early part of winter.
But cranberries are picked early on in the fall sometime in September, and then that continues right up until the middle to end of November, and sometimes even later. This is the official cranberry season where the majority of shoppers are out looking to buy them fresh.
Cranberries are usually made available all year around because of how they are managed.
The majority of the cranberries that get harvested in season are frozen so that they can be used at other times of the year. This is why see cranberries off-season.
So technically cranberries are not a winter fruit. They are picked in the fall, but are usually made available in stores year-round.
Hope this helps.