Thanksgiving hasn't arrived but Boston already has its Christmas tree.

On Friday, the city received its annual gift of an enormous tree from the good people of Nova Scotia, Canada.

Halifax, the provincial capital, sends down one of its home-grown trees every year as a gesture of thanks for the helping hand Bostonians gave it 100 years ago.

On Dec. 6, 1917, a Norwegian supply ship collided with a French munitions vessel, causing a huge explosion, according to the Tree for Boston website. Nearly 2,000 people were killed, hundreds were wounded and 1,600 homes were destroyed. 

Boston came to the rescue, sending a relief train to assist survivors with food, water and medical supplies. Medical workers took over for Nova Scotia staff who had been working without rest.

A year later, Halifax sent a Christmas tree to Boston in thanks. Then in 1971, Halifax made the same donation, and has not skipped a year since.

This year's tree is a 47-foot white spruce, originally from Cape Breton, Nova Scotia, according to the Boston Parks and Recreation Department.

Just as residents and school children send off the tree in Nova Scotia, Santa Claus and Boston schoolchildren, who waved Canadian and Nova Scotian flags, welcomed the tree into Boston Common on Friday. Fans of the annual tradition have been able to follow its voyage down from Canada on the tree's website

Nova Scotia's generosity does not come cheap.

It spent nearly $200,000 last year to send its gift to Boston, CBC reported earlier this week. That included a $41,000 payment to the City of Boston and a $75,000 payment to ABC Boston for its exclusive tree-lighting broadcast. 

This year's ceremony will take place at 7:55 p.m. on Dec. 1, near the Boston Visitors Center at 39 Tremont Street.