First, moisturise and trim hair regularly to reduce dryness and breakage.
In general, most hair types become drier with cold temperature and less humidity. This is particularly due to the decrease activity of sebaceous glands reducing oil secretions. Not to mention, after the days in hot sun, sweating and chlorine in pools, your hair has been stripped of essential oils and nutrients.
It is suggested to apply either a daily moisturiser (oil sheen, lotion and so on) to your hair, especially the ends which are more prone to splitting and breakage when too dry. One of my favourites for dry hair is simply basic olive oil which can be used daily or applied heavily with a plastic cap the night before shampooing or with a thirty minute moist heat treatment. The moist heat works better than the basic hot oil treatment.
Also to further reduce your ends from splitting, it is just as important to get a good hair trim of at least quarter inch every six weeks as your ends are the oldest part of your hair strand.
Second, shampoo hair once a week.
Contrary to popular belief, even during cooler months, you should still wash your hair at least once a week followed by a moisturising conditioner with moist heat to allow ingredients to absorb better. Because of the more frequent moisturising products during the season, if your scalp is not clean often, you can get a build-up creating an environment for growth of the pityrosporum yeast.
This causes your hair follicles to become inflamed and irritated leading to a dry, itchy, flaky scalp called Seborrheic Dermatitis which is commonly called dandruff. Therefore, keeping the scalp clean at least once a week or more with a medicated shampoo containing either zinc, selenium sulfide, coal tar, salicylic acid or ketoconazole to be applied and left on scalp for at least ten minutes to allow deeper penetration into your follicles. Then follow with your favourite moisturising shampoo. Repeat every week until under control then do at least once a month as maintenance.
You may also use a Hydrocortisone Ointment from the drugstore to any itchy scalp area two or three times a day. If issue still persists after a month, seek clinical evaluation by your dermatologist.
Third, keep hair follicles healthier from within.
Regardless of the temperature, it is just as critical to take care of the inside hair follicles. It is to care for your hair properly on the outside. In addition to drinking at least eight to ten glasses of water everyday and eating proper nutrition, you should feed your hair follicles from within as hair grows from the inside of your scalp.
Topical products cannot absorb deep enough into scalp and the basic multi-vitamin hair vitamins are not specific enough. It would be superb if you can use all natural hair supplement.