western Georgia, northwest Iberia, western Great Britain, and western Norway. The maxima along the eastern coasts of water bodies is due to the westerly wind flow which dominates across the continent. A bulk of the precipitation across the Alps falls between March and November. The wet season in lands bordering the Mediterranean lasts from October through March, with November and December typically the wettest months. Summer rainfall across the continent evaporates completely into the warm atmosphere, leaving winter precipitation to be the source of groundwater for Europe. Mesoscale rain systems during the rainy season track south and eastward over the Mediterranean, with western portions of the sea experiencing 20 percent more rainfall than eastern sections of the sea. The European Monsoon (more commonly known as the Return of the Westerlies) is the result of a resurgence of westerly winds from the Atlantic, where they become loaded with wind and rain. These westerly winds are a common phenomenon during the European winter, but they ease as spring approaches in late March and through April and May. The winds pick up again in June, which is why this phenomenon is also referred to as "the return of the westerlies". The rain usually arrives in two waves, at the beginning of June and again in mid to late June. The European monsoon is not a monsoon in the traditional sense in that it doesn't meet all the requirements to be classified as such. Instead the Return of the Westerlies is more regarded as a conveyor belt that delivers a series of low pressure centres to Western Europe where they create unseasonable weather. These storms generally feature significantly lower than average temperatures, fierce rain or hail, thunder and strong winds. The Return of the Westerlies affects Europe's Northern Atlantic coastline, more precisely Ireland, Great Britain, the Benelux countries, western Germany, northern France and parts of Scandinavia. There are cycles seen within the rainfall data from Northern Europe between Great Britain and Germany, which are seen at a 16-year interval. Southern Europe experiences a 22-year cycle in rainfall variation. Other smaller term cycles are seen at 10-12 year and 6-7 year periods within the rainfall record. Places with significant impact by acid rain across the continent include most of eastern Europe from Poland northward into Scandinavia. North America Canada Precipitation across Canada is highest in the mountain ranges in the western portions due to onshore