While Castle Lake has been collecting temperature data for a very long time, more recently it has started to collect water temperature continuously at various depths, providing a temperature profile for the lake. A chain, with loggers as various points, is suspended in the lake, and every five minutes (fifteen minutes during the winter months) a value is collected and stored in the logger.
The movie below, created by Dr. Ted Swift, shows the change in temperature over time at various depths up to 14 meters.
On July 23, 2003, a storm blew in over Castle Lake, and the wind changed the temperature profile of the lake dramatically. The storm hits around the 25 second mark!