It's been more than 20 years since we've seen measurable snowfall on Christmas Day. Here are a few other festive weather facts:

Whether you dream, or dread, the idea of a White Christmas - there's no question snow is on the mind during the holiday season. Snow makes frequent appearances in Christmas movies and decorations, but it's surprisingly absent on Christmas Day.

A True White Christmas

Snow doesn't have to fall on Christmas Day for it to count as a "White Christmas", but there are some requirements that must be met for the National Weather Service to recognize the day to officially declare it. On Long Island, 1" or more of snow must be on the ground at Islip where the official snow observations for the island are kept.

On average, a White Christmas happens just 15% of the time on the island. The most recent was 10 years ago in 2013 after a Christmas Eve snowfall. It just barely made the criteria ... 1" of snow on the ground.

Snow on Christmas

Catching snowfall on Christmas Day is much less common than seeing snow on the ground. Measurable snowfall has only happened three times, most recently in 2002. (That's 21 years ago!) Snowflakes do happen on occasion on Christmas Day - most recently in 2017, but no accumulation was reported that year in Islip.

There are a few recent years where notable snow has fallen very close to Christmas Day. The record for most snow on the ground on Christmas Day was 2009. There were 11" on the ground after a massive snow a few days before. In 2010, the infamous Boxing Day Blizzard brought wind gusts over 60 mph and 2 feet of snow to Long Island. The highest totals on the island were in Massapequa with one report of 23.5" of snow. In the boroughs there were reports of nearly 30" of snow.