Even though it's a weather phenomenon that forms at the equator, La Nina could have a major impact on Canada this winter.
La Nina moves cooler air and water around the Pacific Ocean. It's been seven years since the last one.
In the past, La Nina caused drought and floods around the world. It also whips up more hurricanes in the Atlantic.
Here in Canada, many parts of the country could be in for a long winter.
"It generally means from B.C. to Thunder Bay, a colder and snowier winter," Environment Canada's David Phillips told CTV News.
In the fall, La Nina tends to bring a longer, colder, and wetter-than-normal winter. While its impact is harder to predict for eastern Canada, westerners should prepare for a rough season.
But what will happens is still up in the air. Since its last appearance in 2000, the planet's climate has changed quite a bit. Global warming has progressed and could alter its effects.
But not everyone is expecting the worst. It looks as if La Nina is offering a skier's dream forecast.
"It's very exciting. We're definitely looking forward to another great year and you can kind of feel (that) winter's in the air," said Kelly Aldinger of Grouse Mountain near Vancouver.
