Geography Lake Erie viticultural area is distinguished from surrounding areas by its proximity to Lake Erie which exerts a moderating influence on the area. This proximity to Lake Erie and the influence that Lake Erie exerts on the local climate is the fundamental factor that permits viticulture in this area. Soils, elevations, and other physiographic features within the area are diverse and, through most of the area, reflect the extent of the area that contains sites which can justifiably be said to be suitable for viticulture within the beneficial climatic influence of Lake Erie. T. D. Jordan et al. in their bulletin on
Cultural Practices for Commercial Vineyards (1981), state that: "Temperature is the first consideration in selecting the location of a vineyard. It involves length of growing season, as well as magnitude and frequency of winter minimums. Temperature require consideration in selecting the location of a vineyard. It involves length of growing season, as well as magnitude and frequency of winter minimums. Temperature requirements must be satisfied for a site to be considered." They go on to note that for commercial viticulture in this region a growing season of 165 days is considered minimal and 180 plus days is preferable, and that winter minimum temperature should infrequently fall below and almost never below . Stephen S. Visher, in his book
Climatic Atlas of the United States (1954), summarizes the general climatic effect of the
Great Lakes on their surroundings.Lake Erie's effect on the summer moisture regime are very significant. The area surrounding Lake Erie usually gets significantly greater isolation in the summer months than areas further away from the Lake. The reduced summer rainfall and few fog days, which typically occur only in late winter and early spring, combined with almost continuous lake breezes, distinguish the Lake Erie area from surrounding areas. Also, the Lake Erie area is sheltered to some degree from the potential devastation of hail due to the inhibiting influence that Lake Erie has on thunderstorm vigor and activity. As a result, Lake Erie experiences by far the greatest annual temperature variation of any of the Great Lakes. It ranges from an average surface temperature of in the late summer to 90 percent or more ice cover in the late winter-far more ice than typically develops on any other of the Great Lakes. This wide and rapid seasonal fluctuation of the lake water temperature, and this fluctuation's lag with respect to seasonal air temperature variation, serves a very beneficial climatologist effect throughout the year. In the early spring, the accumulated ice and the very cold water of the Lake serve to cool the climate of the adjacent land against early spring warm spells. In mid to late April, the Lake commences to warm rapidly and then buffers the area against late spring frost. In the summer, the water temperature is warmer than in any other of the Great Lakes. The summer's high temperature is then carried over into fall, warming the air adjacent to the Lake and keeping fall frosts at bay within the Lake Erie viticultural area for a month or more longer than surrounding areas. This results in an average frost-free period of approximately 170 to 175 days with a 200 day frost-free period to be found in some portions of the Lake Erie area, the longest frost-free period in the Great Lakes region. Likewise, proximity to the Lake in winter affords considerable protection against extreme minimum temperatures, with winter minimum temperatures of less than minus ten degrees Fahrenheit being uncommon across most of the Lake Erie viticultural area while inland areas often experience temperatures lower. In many portions of the Lake Erie viticultural area, the
air drainage of a given site greatly affects its microclimate with respect to freeze and low temperature damage. In this regard, the sloping areas found further inland within the Lake Erie viticultural area have rather an advantage over the more level areas often found closer to the Lake, and Lake Erie, by being at the lowest elevation, serves as a vast sink for cold air to drain into. The only portion of the Lake Erie viticultural area in which elevation and physical features play an important role in distinguishing this area from surrounding areas is in
Chautauqua County, New York, and
Erie County, Pennsylvania. In these areas, the high-elevation
Allegheny Plateau with its too short frost-free period and too long winter temperatures clearly limits the "lake effect" to a width as little as inland. ==References==