Humpback Whale Season Has Begun

Some days, the Pacific off Isla del Caño stops behaving like an ocean. No swell, no wind — the surface flattens out until it looks like a mirror. And it's in that rare stillness that the dark back of a humpback breaks the water without warning.

The season is already here. We've been heading out to sea continuously over the past several days, and the pattern is clear: the whales are arriving, and not only that — we've already spotted several mothers with newborn calves moving slowly through the area, taking their time between Caño and the Drake coastline. It's the most reliable sign that the season is genuinely underway.

Why this season is different

Costa Rica has the little-known privilege of hosting two distinct humpback whale populations in different parts of the calendar year: one arriving from the northern hemisphere between December and March, and another — the one now in front of us — migrating up from the southern hemisphere, mainly from Antarctic waters, in search of warm water to give birth and nurse. This second season typically runs from July through October, with its peak usually falling in the coming weeks — right in line with what we're starting to see on the water.

Pregnant females and mothers with newborn calves seek out calm, sheltered water so their young can build strength before the long return trip south. The gulf in front of Corcovado National Park and Isla del Caño offers exactly that kind of protection — and this year, with an extra advantage.

Visibility rarely seen this time of year

The El Niño phenomenon has brought a noticeable drop in rainfall to the area, and that's translated into water clarity that's surprising even to those of us who navigate these waters daily. Around Isla del Caño in particular, visibility has been exceptional — the kind of condition we'd normally expect only during the driest months of the year, not in the middle of the rainy season.

Combined with near-constant calm seas, the result has been outings where you can clearly make out not just a whale's blow and back, but also underwater behavior when the light and angle line up.

What we're seeing out there

• Mothers with calves, moving at a slow, protected pace
• Relaxed surface behavior — long, unhurried breaths, minimal movement
• Flat-calm seas on several recent days, ideal for extended, stable observation
• Excellent underwater visibility around Isla del Caño, favored by the drop in rainfall

The invitation

The coming weeks will mark the peak of this season. If you've ever wanted to see a humpback whale and her calf in calm water, with Isla del Caño as the backdrop, this is the moment — not just because of the season, but because of the unusual sea conditions we're having right now.

We'll be waiting on the river, headed out to sea.

— Sierpe Tours