The San Juan Islands average 247 days a year of sunshine. This is due in large part because San Juan Island is "protected" by surrounding ocean waters, and mountain ranges. The ocean temperatures average 45 degrees in the winter and 52 degrees in the summer. San Juan Island also only recives about half the rainfall that Seattle does, an average of 29" per year. The average temperatures ranges from a high of 80 in the Summer months and and an occasional 30 degree day in the winter time. The islands enjoy all four seasons. It does occasionally snow here. However, it only snows about once or twice a year and usually not much more than an inch or two. Island tides range over 14 feet. The extreme low tide of -4.0 feet to the extreme high tide of over 10 feet.