River use permitted 24 hours a day, year-round, unless closed due to flooding, ice floes or other hazardous conditions. Most private liveries and campgrounds open mid-April through October. Moderately high humidity. Occasional thunderstorms and dense fog. Spring and fall climate is variable.
Temperature can drop rapidly after sunset on occasional warm days.
Wetsuits may be required for river use. Water temperatures drop from the 50s to the 30s by December, with most of the river usually freezing over each winter. Be prepared for rain and cold weather at any time. Hypothermia is possible, especially on the river, even during the summer. Boaters and anglers should be prepared for cold water.