Moderately high humidity. Occasional thunderstorms and dense fog. Spring and fall climate is variable.
Temperature can drop rapidly after sunset on occasional warm days.
Wet suits 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 in any season. Be prepared for rain and cold weather at any time. Hypothermia is possible, especially on the river, even during the summer.