The incidence of psoriasis was closely related to climatic factors, and the mean air temperature, air pressure, relative humidity and total annual precipitation were negatively correlated with the incidence of psoriasis. Most of the patients are more severe in winter and less severe in summer, with a small number of cases occurring in other seasons. Some patients have obvious onset seasons in the early stage, but there is no seasonality after repeated attacks. The annual mean air temperature, air pressure, relative humidity and total precipitation were negatively correlated with the incidence of psoriasis. The higher the air temperature, the lower the air pressure, the higher the relative humidity and the higher the annual precipitation, the lower the incidence of psoriasis, and vice versa. The time and intensity of illumination had little influence on psoriasis.

        In the northern region, the winter is cold, the spring and autumn lasts for a short time, and the temperature varies greatly. In addition, the air is dry and there is less precipitation, so the prevalence rate of psoriasis is much higher in the north than in the south. The southern region has a long duration of spring and autumn, mild temperature change, more precipitation and moist air, so the prevalence rate in the south is significantly lower than that in the north. It can be seen that climate and living environment play an important role in the pathogenesis of psoriasis.

        However, the influence of climate on psoriasis is comprehensive, and a single factor does not play a decisive role in the incidence and prevalence of psoriasis.