Abstract: A,method of Long-range weather forecasting based on month to month correlation of weather elements is proposed. By this method, we can forecast a large number of monthly weather elements such as mean temperature, mean maximum temperature, mean minimum temperature, absolute maximum temperature, absolute minimum temperature, total amount of precipttarlon, number of rainy days, clear days, days of over-cast, amount of insolation and etc. As this kind of forecast can be worked out many months before, so not.only one month, but also seasonal or even half-year long-range weather forecasting can be made. Besides, this method can be applied also to make ten-day forecasting.