Ready, Set, Chonk: Fat Bear Week 2025 Is About To Begin. And Yes, It's Early

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What is Fat Bear Week?

You’ve heard of March Madness? Fat Bear Week is basically like that, except instead of a bracket full of basketball teams, there are the brown bears of Alaska’s Katmai National Park and Preserve, and the title that they’re competing for is the chonkiest bear of them all.

And best believe this is a week of bear-related body positivity – everyone is celebrating how deliciously rotund the bears of Katmai are. So strong is the fandom behind these bears that it takes over social media feeds every year, with people showing no hesitation in loudly supporting their favorites (including in the IFLScience office. Yes, we have a sweepstake).

When is this year’s competition?

Typically, the competition occurs in early October, but we’ve had an early fall surprise with the National Park Service announcing on social media that this year’s competition will run from September 23-30, 2025. If that’s not enough to satisfy your desire for ursine chonkery, the younger bears of Katmai will be taking part in Fat Bear Junior starting September 18-19.

How is the winner decided?

Luckily for the team at Katmai, no one is actually popping these bears on a scale – the cost of the insurance for whoever they’d hire to do that doesn’t bear (heh) thinking about. Instead, the bears are pitted against each other in a daily public vote for the thicc-est in the land. Two bears are eliminated each day, and by the end of the week, voters have to pick a winner from the final two. 

This does mean that whoever comes out on top might not actually topple the scales, but hey, even the smallest of bears can still have big bear energy. Let’s just hope there’s not any voter fraud this time around.

Why do they need to acquire such god-tier levels of chonk?

It’s a matter of survival – it’s fast approaching the time for hibernation, and while in their metabolic slumber, bears can lose up to a third of their body weight. Piling on the pounds is their way of preparing for this, and Brooks River at Katmai provides plenty of tasty, fat-rich salmon to help the bears on their way.

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Who’s the strongest contender for this year’s crown?

We’re yet to find out who’ll be in this year’s bracket, but it’s likely to include some past favorites. There’s the much-loved mama bear and reigning champ Grazer (formally known as bear 128); she’s won the previous two competitions, but last year’s win was particularly poignant for fans as she beat out Chunk (32), who was behind the death of one of her cubs earlier in the year. We’ve been keeping an eye on Katmai’s webcams, though, and Walker (151) – who’s heavy every year and yet has never won – is looking pretty hefty already.