 In February 1945 the city recorded a maximum snow cover of , but the extreme low of was recorded 14 years earlier.In contrast, Sapporo's heaviest snowfall occurred in 1939, and that was only , and more northerly Wakkanai has recorded similar maxima.The particularly heavy snow is caused by several winds that collide around the city and make the air rise and cool, resulting in quick, thick cloud formation followed by intense precipitation.