Clarification: Are you asking about a) interview DATES in January or b) interview OFFERS in January.
Being offered an interview in January is somewhat late for most programs, and as such you'll probably be lower on their list already (because more desirable candidates were offered interviews earlier, and enough of them cancelled to open up a spot for you).
On the other hand, having an interview date in January is very common. Most of my interviews were in January. November interviews are really early and not generally offered, December interviews are usually limited by the holidays, so I would think that most people do most of their interviews in january. This in no way is detrimental to match success.