Temperate climates are those without extremes of temperature and precipitation (rain and snow). The changes between summer and winter are generally invigorating without being frustratingly extreme. There are two types of temperate climate: maritime and continental. The maritime climate is strongly influenced by the oceans, which maintain fairly steady temperatures across the seasons. Since the prevailing winds are westerly in the temperate zones, the western edge of continents in these areas experience most commonly the maritime climate. Such regions include Western Europe, in particular the UK, and western North America at latitudes between 40 and 60° north.
Continentality increases inland, with warmer summers and colder winters as the effect of land on heat receipt and loss increases. This is particularly true in North America, where the north-south aligned Rocky Mountains act as a climate barrier to the mild maritime air blowing from the west. Maritime climate, on the other hand, penetrates further into Europe where the major mountain range - the Alps - is orientated east-west.