Management Plan - National Estuarine Research Reserve System

Figure III.3. The two principal watersheds of the Wells National Estuarine Research Reserve.dune systems. The Ogunquit River empties into theGulf of Maine in the Town of Ogunquit.The Gulf of Maine monthly mean wave height isgreatest from November to March and is lowestin July and August. Annual mean wave height isalmost 20 inches. Semi-diurnal tides have a rangeof 8.5 to 9.8 feet.ClimateThe climate of south coastal Maine is the mildest inthe State of Maine. As a rule, south coastal Mainehas very pleasant summers and falls, cold winterswith frequent thaws and unpredictable springs. TheReserve’s weather station indicates average annualtemperatures ranging from 45 to 49°F (7.2 to 9.6°C).Twelve weeks per year show average temperaturesbelow freezing, and the warmest 8 weeks of the yearaverage around 68°F (20°C). Few summer nightsare too warm and humid for comfortable sleeping.Autumn has the greatest number of sunny days andthe least cloudiness. There appears to be moderatereduction in sunlight in the first few weeks ofJuly, perhaps due to fog as newly warmed inlandair meets the still cold air at the ocean’s surface.Winters are quite severe, but begin late and thenoften extend into the springtime. Heavy seasonalsnowfalls, over 100 inches (2,540 mm), occur aboutevery 10 years. True blizzards are very rare. TheWhite Mountains, to the northwest, keep considerablesnow from reaching the area and also moderatethe temperature. Normal monthly precipitation isremarkably uniform throughout the year. Windsare generally quite light with the highest velocitiesbeing confined mostly to March and November.Even in these months the occasional northeasterlygales have usually lost much of their severity beforereaching the coast of Maine. Temperatures well20 Wells National Estuarine Research Reserve