Does Lake Coeur d'Alene Freeze Over?

Rarely, and not completely in recent decades. Lake Coeur d'Alene (Idaho's second-largest natural lake, 25 mi long, max depth 220 ft / 67 m) has not frozen over fully since the winter of 1968–69.

Why It Doesn't Freeze

• Volume & depth: Large heat reservoir; deep water stays ~4°C (39°F) year-round.
• Wind & fetch: 25-mile length allows wave action, preventing stable ice formation.
• Climate warming: Winter temps trending up; fewer sustained sub-zero stretches.
• Inflows: Coeur d'Alene River, St. Joe River bring relatively warmer water.

Partial Ice

• Shallow bays (Wolf Lodge Bay, Harrison, Rockford Bay) may skin over in cold snaps.
• Ice thickness rarely exceeds 2–3 inches — unsafe for walking, skating, fishing, or vehicles.
• Idaho Dept of Parks & Recreation does not monitor or certify ice safety on Coeur d'Alene.

Historical Note

The 1968–69 freeze was exceptional: weeks of -20°F (-29°C), low snow cover (insulation), calm winds. People drove cars on the lake. Such conditions are increasingly improbable.

Winter Activities Instead

• Bald eagle watching (hundreds winter at Wolf Lodge Bay — spawning kokanee)
• Snowmobiling on groomed trails (Idaho Panhandle National Forest)
• Cross-country skiing (Trail of the Coeur d'Alenes — 72 mi rail-trail)
• Coeur d'Alene Resort: heated dock, fireplaces, holiday lights

Enjoy the lake in winter — but don't count on ice.