It is bad to go skiing in New Zealand during the summer.
Step-by-step explanation:
During summer most of the skiing places are closed because there is no snow in the field. December is the mid-summer phase in New Zealand and in this period of time not much of snow is available for the smooth skiing experience.
So it is recommended for the visitors to visit New Zealand in winter when there is abundant snow available for the best skiing experience. But there are many other adventurous activities to perform in New Zealand in summer days.