Who uses it: New Englanders
What it means: The day when the last of the ice disappears from a lake or river.
How you can use it: To celebrate spring.
Anna discusses this term (with pictures) at her blog; she and her husband live on China Lake, where the annual going-out of the ice is a big event.
Fishermen are out in force along the Kennebec River. A sign at Gardiner Landing reminds everyone that fishermen are limited to no more than two quarts of smelt a day between March 15 and June 15... I can't imagine what anyone would do with two quarts of smelt (a small fish like a sardine), so the limit doesn't change my lifestyle any.
I didn't wear The Coat at all yesterday, and it'll be even warmer today. It's weird, I feel kind of defenseless without it.