Lack of moisture is the reason for dry flaky skin therefore it is important to drink at least two litres of water per day. A dry atmosphere will take water from wherever it can so you will probably find yourself applying moisturiser more often than usual.
Another reason for skin feeling tight and itchy can be wrong choice of cleanser. Our skin has an acid mantle layer which is a protective barrier. Soap is usually alkaline in nature therefore disturbs this protective layer. For this reason you should be careful about choosing the correct cleanser. A general guideline is to use a creamy cleanser for dry, dehydrated and sensitive skins, a cleansing lotion for younger, excessively oily skins and a gel or foaming cleanser for oily and combination skin.