Yes you will need to adjust your skincare regime according to the seasons, especially if you live in high altitude areas. In winter you need more hydration as we do not drink enough water and our skins are exposed to heaters etc., so you will add on more moisture and a hydrating serum. You may also find you need more exfoliation so a stronger retinoid or enzyme exfoliator can be added to your regime. Whereas in summer a lighter moisturiser will be used and you will need more of an anti-oxidant serum to protect your skin from free radicals and sun damage.