Our water year greatly depends on the snowfall in the high country. In 2010 Warm River & Island Park had roughly 17.85 ft or 214" of snowfall & in Ashton there was 6.75 feet of snowfall.
Snow will slowly start melting in the lower valleys in March and April, but snow regularly falls in the high country. Fishing can be incredible before the major runoff; this is typically is in April and May. By late May in a typical snow year, the majority of the snow has melted and the rivers are full. By June, the weather is perfect, the rivers are fishing, and life is beautiful.
Summers can be relatively short, but very beautiful and mild. Temperatures can reach 100 degrees; however, the average temperature is in the high 80’s. Fishing is typically great in every river, lake, and spring creek around the area. Those of you that enjoy hiking, camping, and fishing in Yellowstone National Park, Teton National Park, and in the high backcountry will enjoy the weather and the lack of snow above 9000 feet.
Autumn in Idaho is breathtaking. The trees are colorful, the water is low, and the fishing is excellent. Fall brings the time of year we like to call "Indian summer". The nights are cold and you can have some mornings with frost and the days are warm bringing temperatures above 70 degrees. In any Rocky Mountain fall weather, the need to dress in layers is very important and makes life a little more comfortable.