It is a little challenging to dress a newborn in the wintertime, but not impossible at all. The best thing you can do is take into account the following rule: dress him up in layers.
Babies need fresh air, even when it’s cold outside and even if they are newborns. So make sure to keep him warm with plenty of layers in natural fabrics.
The first layer can be snug, a bodysuit and leggings are great for this. The second layer can also be a pair of pants and a long sleeve if it’s freezing outside. The third layer can be a jacket or an overall, mittens, a hat, and warm booties. Don’t forget about the socks and a bib.
Newborns and babies lose body heat faster than adults and older children. So make sure to dress them appropriately when you take them out.
For the inside, a bodysuit, a long sleeve, and pants are just fine. Keep the temperature around 69-71 degrees and he’ll be comfortable.