Yes, the first day of spring may technically be on March 20 this year, but many Granite Staters don’t start celebrating the end of winter until ice-out is declared.

For those unfamiliar with this harbinger of spring, it occurs when ice-out go-to guy Dave Emerson of Emerson Aviation in Gilford can fly over Lake Winnipesaukee and see that the ice has melted away enough to allow the MS Mount Washington ship to safely cruise between ports in Alton Bay, Center Harbor, Meredith, Weirs Beach and Wolfeboro.

Before Emerson makes that call, however, it’s fairly up in the air as to when you should pack your wooly sweaters away. So much so, winnipesaukee.com hosts a yearly contest allowing folks to take a guess at when ice-out will occur. The three people who get the closest can select their prize from the website’s online store. The guessing period for the online contest has already ended, but that doesn’t mean you can’t still take a stab at it and create your own competition with your friends and family.

To help you get started, here are five things to keep in mind.

– The earliest date ice-out happened was March 28, 1921 – the latest, May 12, 1888.

– The date that has had the most ice-outs is April 20 (years 1984, 1901, 1932, 1950, 1952, 1963, 1966, 1967, 1984, 2004, 2005 – for 11 total).

– On average, ice-out occurs mid-April.

– Emerson declared last year’s on April 12 around noon. Most of you were probably enjoying time with the family, eating dinner or noshing on chocolate bunnies, because it was Easter Sunday.

– Over the past 10 years, all ice-outs were in April, except for one on May 2, 2001.

For more information and for a list of ice-outs by year (starting in 1887!), visit winnipesaukee.com. Happy guessing!