Web searches for 'dry skin' and related terms like 'dry face' and 'skin moisturizer' demonstrate distinct variations by season of the year and location. The overall search pattern for 'dry skin' in the United States for the past four years is depicted in the chart below (data from Google Trends). The seasonal trends largely represent changes in indoor drying stresses on skin that reflect increases and decreases in outdoor water vapor levels.
Another interesting aspect of the chart is the gradual increase in search activity involving 'dry skin', which could be a function of the growing portion of the aging US population susceptible to dry skin as well as an increase in Internet search activity among members of this population cohort.
An important observation is that as the Fall months begin, the atmosphere begins to dry out, and consequently, there is a rise in people's concern about the occurrence of dry skin. So, as Fall begins, its probably helpful to inspect those areas of your skin that are prone to dryness, as evidenced by skin roughness and skin flakes, in order to establish a baseline condition. Then, as winter approaches with even drier outdoor/indoor air, you'll be able to respond with moisturizing lotions and creams together with a bedroom humidifier when indoor relative humidities decline below 40%.