Actually, I believe Jesus was born in October.
Why?
For one, shepherds wouldn't have sheep pasturing late in December. While winter is generally brief in that part of the world,
it still comed for a few weex.
I believe Dec. 25 was chosen, because on shadow calendars, that's the first day the sun has moved north enough to move the shadows on such calendars or solstice-markers a little south. (It's barely-noticeable, & takes quite a long shadow on precise markings to show it.)
Another possible reason is that the Annunciation to Mary that she would be the mother of Jesus was supposedly made on the 25th of March, exactly 9 months before Dec. 25.
The Dec. 25 date was first used in 336 AD during Constantine's reign. While many used the Julian calendar, farmers & others whose livelihoods were dependent upon accurate predicting of the seasons used a calendar made by observing the solstices & counting the days between them. This led to the Gregorian calenday used by mosta the world today.
In Scandinavis & parts of northern Europe, the winter solstice was & still is called "Yule", giving English Yule logs, Yuletide, etc.
Nothing wrong with having a time of good cheer among people, & thinking more of Jesus no matter when His actual birthday was. The IMPORTANT thing is that IT HAPPENED ! ! !