Some babies are more prone to dry skin than others, but most have trouble with it in the wintertime. The reason is dry, overheated indoor air.

What can I do about my child's dry skin?

Don't give baby long, hot baths. Instead of a 30-minute bath, cut bath time down to about ten minutes. Use warm— not hot — water. Try soap-free products and cut back on bubble baths.

Keep your baby’s skin well moisturized. Once you take your child out of the bath, quickly and lightly dry him with a towel, then apply moisturizer immediately. If your child's skin is still dry even with daily moisturizing, try switching from a lotion to a thicker cream or ointment. Reapply once or twice more each day.

Keep your child well hydrated. Dry skin lacks water. Offer your child plenty to drink year-round to replace the moisture that's evaporating from his skin.

Keep baby's room humidified. If the air in your home is dry, use a cool mist humidifier in your child's room.

Laundry Tips. Use a gentle detergent to wash everything that touches your infant's skin, from bedding and blankets, to towels and even your own clothes.

If dry patches start to spread, crack, or seem painfully itchy, consult your pediatrician.

Source
Baby Center WebMD
What to Expect