FAQ: "Does the lake freeze
hard enough to walk on?"
The shallow lake may appear to be frozen solid, but
don't count on it. The water level is constantly fluctuating, and
there is enough movement under the ice to make it unstable.
The times it has been solid enough to walk on the temps
had to be below 20 deg for at least two weeks to be safe. Even then,
the ice will heave and crack as the water level underneath drops to create
a void. And, if it freezes solid, a few days above 32 and the ice
starts to crack and soften.
Never drive a vehicle across the ice.