Moderately high humidity. Occasional thunderstorms and dense fog. The spring and fall climate are variable.
Temperature can drop rapidly after sunset on 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. Always dress in layers. Be prepared for rain and cold weather at any time. Hypothermia is possible, especially on the river, even during the summer.