Hi
Dryness of lips is very common in the summers.
It is caused because of dehydration in summers in-spite of drinking plenty of water.
Various moisturising agents can be effective to look after dryness.
Sometimes it may occur due to
vitamin deficiency also which can be corrected by taking oral vitamin supplements.
In case of further doubts, please feel free to write back to me.
Regards
Dr Prashik Meshram