What’s the weather like in New York City during the holidays? Usually, pretty darn cold – though this can fluctuate. Last year, December temperatures ranged from highs of 66°F (18°C) to lows of 27°F (-2°C), averaging 45°F (7°C) for the month.
https://www.lonelyplanet.com/articles/nyc-holiday-travel-questions-to-ask-before-you-go