Lake Effect

Appears in
Oxford Companion to Wine

By Jancis Robinson

Published 2006

  • About

lake effect, the year-round influence on vineyards from nearby large lakes which permits vine-growing in areas such as the north east united states and Ontario in canada despite their high latitude. In winter, the large lakes provide moisture to the prevailing westerly winds, which creates a deep snow cover, protecting vines from winter freeze even in very low temperatures. The lake may eventually freeze, depending on the size. In spring, the westerly winds blow across the frozen lake and become cooler. These cooler breezes blowing on the vines retard budbreak until the danger of frost has passed. In summer the lake warms up. By autumn/fall, the westerly winds are warmed as they blow across the lake. The warm breezes on the vines lengthen the growing season (balancing the late start to the growing season) by delaying the first frost. In other parts of the world, lakes and large inland seas also moderate climate through temperature effects alone. See maritime climate.