As you may have ascertained, it is never winter in Neverwinter. However, magic can be unpredictable and so can weather. On rare occasions, these idiosyncrasies intersect, and it becomes cold enough in the city to maybe wear a coat.
Folks who have adapted to life in cold climates can usually tolerate plummeting temperatures with a shrug, but people living in warm climates seem to notice every drop of one degree on the thermometer. In Neverwinter, as soon as there's a slight chill in the air, residents call it a "littlewinter" and retreat to the tavern to order a hot toddy. This popular variation is so delicious, with its mix of maple syrup, cinnamon, and brandy, that one almost hopes for a little winter to appreciate it!