Swimming
There are several water bodies in Crater Lake National Park, however, the streams and ponds are often very inaccessible and managed as wilderness areas. And, most swimmers want to swim in Crater Lake itself.
Cleetwood Cove is the only legal and safe access to the edge of Crater Lake. Visitors are welcome to swim in the lake in this area. This is accessed by the Cleetwood Cover Trail.
Crater Lake temperature
Although Crater Lake is too deep to ever reach a truly comfortable temperature (even in the summer), plenty of people take the plunge and do a few quick strokes to cool down after hiking the Cleetwood Cove Trail or after exploring Wizard Island. But this is an informal activity, and there are no facilities for swimmers.
Keep in mind that Crater Lake is accessible only from about June 15 through September 15 of each year due to our extreme snow conditions. Earlier or later dives may be possible, but cannot be guaranteed due to the variability of our weather.
Surface temperatures of the lake water vary between 32°F (0°C) and 66°F (19°C). Summer temperatures range normally between 50°F (10°C) and 60°F (16°C). Water more than 260 feet (80 meters) beneath the surface remains cold all year long at a temperature near 38°F (3°C). During the hottest time of the summer, the top water layers warm and become less dense than colder water below. This condition of thermal stratification usually continues into September.
The lake rarely freezes in winter because of the large heat content of the lake, windy surface conditions, and relatively mild air temperatures. The most significant freezing event in recent history occurred between January and April in 1949. The lake was mostly covered with ice twice in 1985, in January and again in December.
