The Polish climate is generally moderate. Summer is usually warm, sometimes quite hot with temperatures above 25°C. Autumn may be cold and rainy, but it often starts quite late, in October, and winters are snowy (especially in the South of Poland) with low temperatures, even down to about - 15°C or - 20 °C. Spring comes in April or May and it gets agreeably warm quickly. Toruń can get humid because of its proximity to the national river, the Vistula (WISŁA).