Answer:
Although snow occupies Crater Lake National Park throughout 8 months of
the year (average annual snowfall is 14 m, or 533 in), the lake rarely
freezes over. There have
been only two reports of this ever happening. It was completely covered
by ice from March 14 to mid May during the winter 1949 and four days in
February, 1924. In April, 1983 about 95 percent of the lake froze. The
immense depth of Crater Lake acts as a heat reservoir that absorbs and
traps sunlight, maintaining the lake temperature at an average of 12.8
°C (55 °F) on the surface and 3.3 °C (38 °F) at the bottom throughout
the year. The surface temperature fluctuates a bit, but the bottom
temperature remains quite constant.
