Book 30, Question 33
What is ice-out, and why do people record it?
Ice-out is the day when the ice cover melts and breaks up on a lake.
Before then, the ice turns gray and may form long needle-shaped crystals called candle ice. People have written down the ice-out dates on some lakes for more than a century. Because these dates come earlier in warmer years, they help scientists see how climate changes.