Cruise season runs from mid-May to late September. The most popular sailing dates are from late June through August, when warm days are apt to be most plentiful. May and June have traditionally been drier than July and August. Alaska's early fall brings the splendor of autumn hues and the first snowfalls in the mountains. The animals have returned to low ground, and shorter days bring the possibility of seeing the northern lights. Daytime temperatures along the cruise routes in May, June, and September are in the 50s and 60s. July and August averages are in the 60s and 70s, with occasional days in the 80s.