Oftentimes, dry lips can be easily treated with over-the-counter products and self-care measures.
OVER-THE-COUNTER PRODUCTS
Apply a lip cream or a lip balm before going out to protect your lips from dry weather. Look for products that have beeswax and petrolatum.
In addition, you should also look for a lip cream or lip balm that has a Sun Protection Factor or SPF. A SPF number tells us how effective that lip cream or lip balm is in blocking the harmful rays from the sun. Look for products that have Aminobenzoic Acid.
Examples include: Carmex Click-Stick Lip Moisturizer SPF 15, Neutrogena Lip Moisturizer SPF 15
AT HOME REMEDIES
Drink plenty of fluids like water and juice to keep your body hydrated.
Put a humidifier in your room to add moisture to your surrounding environment.
Frequently licking your lips can strip your lips of the natural oils that are used to protect the lips from water-loss. In addition, your saliva has acids. So, these acids can further damage the skin cells in your lips, leading to cracks/splits.
References
http://www.mayoclinic.com/health/chapped-lips/AN01440
http://www.nlm.nih.gov/medlineplus/ency/article/002036.htm
http://www.webmd.com/healthy-beauty/features/why-your-lips-are-chapped