A line of low hills southeast of the airport, near the ocean, which reach a maximum height of l60 feet, shuts off sight of the ocean from the airport. Sebago Lake with an area of 44 square miles is situated about l5 miles to the northwest and 45 miles farther are the White Mountains, averaging 3,000 to 5,000 feet in height. As a rule, Portland has very pleasant summers and falls, cold winters with frequent thaws, and disagreeable springs. Very few summer nights are too warm and humid for comfortable sleeping. Autumn has the greatest number of sunny days and the least cloudiness.
Winters are quite severe, but begin late and then extend deeply into the normal springtime.
Heavy seasonal snowfalls, over l00 inches, normally occur about each l0 years. True blizzards are very rare. The White Mountains, to the northwest, keep considerable snow from reaching the Portland area and also moderate the temperature. Normal monthly precipitation is remarkably uniform throughout the year. Winds are generally quite light with the highest velocities being confined mostly to March and November.