What causes dry and chapped lips?
The skin on our lips is relatively thin which makes it prone to becoming dehydrated. Lips can become dry because of environmental, behavioural, and biological factors – discover the main causes of dry and chapped lips:

Cold Weather: One of the main contributing factors to lips becoming dry and chapped is cold weather; lips are most likely to become chapped during the winter due to exposure to cold air, low humidity, and harsh winds. These harsh weather conditions sap lips of their moisture and make them feel dry which can lead to flaking, cracking and chapping.
Air Conditioning: Lips can also become dry during the summer due to the drying effects of air conditioning. Air conditioning circulates cold air around an enclosed space which causes a lack of moisture in the air. This can have the same drying effects on lips as spending time out in the cold.
Sun Damage: Exposure to harsh sunlight can result in sun damage which causes skin to become rough and dehydrated. Your lips can get sunburnt when you spend time in the sun which results in moisture loss from your lips that causes them to become dry and damaged.
Dry Skin Type: If you naturally have a dry skin type, it’s likely that you could be prone to dry lips due to the lack of moisture within your skin. People with dry skin often retain less moisture which leads to the development of dry patches and flaky skin, especially in areas like the lips where skin is thinner and more susceptible to dryness.
Dehydration: Are you drinking enough water, darling? If you don’t regularly hydrate by drinking plenty of water, it’s likely you will experience regular dehydration. One of the first places dehydration manifests itself is the lips; when you are dehydrated your mouth may feel dry and scratchy and your lips may start to chap and crack.
Licking Lips: When lips feel dry it can seem like licking your lips is a helpful way to add moisture back, however, this is actually counter-productive. Licking your lips provides momentary relief by coating lips with moisture, but this quickly dries and can make your lips begin to feel even drier. Instead, the best way to rehydrate your lips is with hydrating lip care like my Life-Changing Lip Mask.