british columbia's climate is best described as varied. the mountainous terrain causes huge changes in climatic conditions over short distances. all winter long the coast is pounded with storm after storm off the pacific ocean. the coast mountains, cascades and also the skeena and hazelton mountains block most of the precipitation which forces the majority of the precipitation to fall on the west side of the mountains. in contrast, the leeward side is much drier with some areas classified as semi-arid. the coast of british columbia is by far the wettest area in canada, while areas located 150–200 km inland are some of the driest places in canada outside of the high arctic. most of northern bc as well as many mountain highways have a subarctic or subalpine climate.