Uvita Whale Watching Season — When to Go (Month-by-Month Guide)

The Two Humpback Populations

Humpback whales follow a predictable annual pattern: they feed in cold, nutrient-rich polar waters during summer, then migrate thousands of kilometres to warm tropical waters during winter to breed and give birth. Because the Northern and Southern Hemispheres have opposite seasons, two separate humpback populations time their migrations to arrive in the same tropical waters at different points in the calendar year.

Bahía Ballena sits at the convergence point of both migration routes. North Pacific humpbacks — which feed in the waters off Alaska, British Columbia, and the California coast — arrive in the South Pacific tropics between July and October to breed and calve. South Pacific humpbacks — which feed in Antarctic and sub-Antarctic waters off southern Chile and Argentina — arrive in the same Costa Rican waters between December and April.

This is why Uvita has one of the longest whale watching windows in the world: combining both seasons, whales are present in Bahía Ballena for approximately 8 months of the year.

• North Pacific humpbacks: feed in Alaska/BC/California; breed in Costa Rica July–October
• South Pacific humpbacks: feed near Antarctica; breed in Costa Rica December–April
• Both populations use the same Bahía Ballena waters — not different locations
• August–September overlap: both populations present simultaneously

January and February — South Pacific Season: Active

The South Pacific humpback season is well underway. January and February are strong months for whale watching with this population — adults engaging in competitive mating groups (male competitors surrounding a single female) are common, and mother-calf pairs from the previous season's births are still present in the bay. Ocean conditions in January and February are generally calm — the dry season is beginning along Costa Rica's Pacific coast, and seas are typically flat in the morning.

• South Pacific humpbacks: active and numerous
• Competitive pods (male-female-escort groups): common
• Mother-calf pairs from November–December births still present
• Whale season rating: ★★★★☆ (4/5)
• Ocean conditions: calm — early dry season

March and April — South Pacific Season: Late but Still Active

March is one of the last reliable months for South Pacific humpback whale watching in Uvita. The population begins departing in April as water temperatures shift and the migration south toward Antarctic feeding grounds begins. Early March still offers good sighting rates; by late April, encounter frequency drops noticeably.

Dolphin sightings remain excellent regardless of whale season.

• March: South Pacific humpbacks still active — good sighting rates
• April: population begins migrating south — declining frequency
• Whale season rating for March: ★★★★☆ (4/5)
• Whale season rating for April: ★★★☆☆ (3/5)
• Dolphin sightings: excellent year-round regardless of season

May and June — Transition Gap

May and June represent the gap between the two whale seasons. The South Pacific population has departed, and the North Pacific population has not yet arrived. Whale sightings in May and June are possible — occasional humpbacks are observed in Bahía Ballena outside the main seasons — but should not be expected.

These months are better treated as dolphin watching months. Spinner and bottlenose dolphin encounters are excellent during the transition period, and sea turtle activity increases.

• May: South Pacific humpbacks mostly gone — occasional stragglers only
• June: lowest whale activity of the year in Uvita
• Whale season rating: ★★☆☆☆ (2/5) — manage expectations
• Dolphin sightings: excellent — this is the right time for a dolphin-focused tour
• Sea turtles: olive ridley nesting season begins on nearby beaches

July and August — North Pacific Season: Peak

July marks the arrival of North Pacific humpbacks in Bahía Ballena — and with their arrival, Uvita's most spectacular whale watching period begins. July sees increasing numbers of North Pacific humpbacks entering the bay, with sighting rates rising week by week through the month. By August, both the North Pacific season is at full strength AND the final South Pacific individuals may still be present — creating the highest density of humpbacks in the entire year.

August is statistically the single best month for whale watching in Uvita. The bay can hold significant numbers of whales simultaneously, with multiple sightings in a single 2–3 hour tour being common rather than exceptional. Competitive mating behaviour — large groups of male whales competing for females, producing dramatic surface aggression — peaks in August.

• July: North Pacific humpbacks arriving — sighting rates climbing rapidly
• August: PEAK month — highest whale density of the year
• Overlap possible: North Pacific + remaining South Pacific individuals
• Competitive mating pods: dramatic surface behaviour with multiple males
• Whale season rating: July ★★★★☆ / August ★★★★★ (5/5)

September and October — North Pacific Season: Excellent

September continues the peak North Pacific season with no significant drop in activity from August. Mother-calf pairs are particularly prominent in September as calves born in July and August become more mobile and visible at the surface. September is an especially good month for calf sightings — young humpbacks are more surface-active and more likely to engage in playful behaviour near the boat than older individuals.

October is the final month of the North Pacific season. Sighting rates remain very good through mid-October, then begin declining as the population starts the long migration back to northern feeding grounds. Book October departures for early-to-mid month if possible.

• September: excellent — mother-calf pairs and calves very active
• September: calves born this season now large enough to be highly visible
• October (early): good sighting rates — North Pacific season still active
• October (late): declining frequency as population begins migration north
• Whale season rating: September ★★★★★ / October ★★★★☆ (4/5)

November and December — Transition and Return

November is the second quiet month in Uvita's whale calendar. The North Pacific population has mostly departed, and the South Pacific population has not yet arrived. Occasional humpback sightings do occur in November, but consistency is low — treat it as a dolphin month.

December brings the return of South Pacific humpbacks, typically arriving in the second half of the month. By late December, sighting rates are rising toward the January–February peak.

• November: second gap period — low whale activity, dolphin tours recommended
• December (early): South Pacific humpbacks beginning to arrive
• December (late): sighting rates improving week by week
• Whale season rating: November ★★☆☆☆ / December ★★★☆☆ (3/5)
• Christmas and New Year weeks: South Pacific season building — good timing

Included at $93 per Person

• Guided whale watching boat tour inside Marino Ballena National Park
• Naturalist guide on board throughout
• National park entry fee
• Life jackets and safety equipment
• Water on board

Not Included

• Snacks or meal service
• Underwater photography
• Transport to/from Playa Uvita
• Gratuity

What to Bring

• Reef-safe mineral sunscreen — chemical sunscreen is prohibited inside the national park
• Polarized sunglasses — makes it much easier to spot distant surface blows
• Motion sickness medication if needed — take 30–60 minutes before boarding
• Binoculars — for spotting blows at distance before the boat approaches
• Light windproof layer — the boat creates significant wind chill at cruising speed
• Waterproof case for camera or phone — sea spray is routine

What's Not Allowed

• Chemical sunscreen (oxybenzone-based) in the national park
• Entering the water near whales or dolphins
• Feeding any marine wildlife
• Approaching individual whales more closely than the guide-specified distance
• Flash photography directed at whale eyes

Best For

• Travellers who have flexibility in their travel dates and want to use this season guide to plan around peak whale activity
• Budget-conscious guests who want a certified national park departure with a meaningful review track record at under $100
• Repeat visitors to Costa Rica who have done other wildlife tours and now specifically want to time a visit for whale season
• Photographers planning a dedicated whale photography trip — this guide will help you pick August or September for maximum sighting frequency
• Families and couples who want to understand what to expect before committing to a tour date

Not Suitable For

• Guests visiting in May, June, or November who have immovable travel dates and expect to see humpbacks — dolphin watching is the more realistic expectation in the gap months
• Travellers who want the highest-rated guide experience — the 4.0-star rating is the lowest among the tours we list; the [expert naturalist tour](/best-whale-watching-tour-uvita/) at $96 has a 4.7-star rating and specialist cetacean guide
• Guests prone to seasickness on longer boat tours — the [cruise-style comfort boat](/whale-watching-cruise-uvita/) is a better vessel option
• Wildlife photographers who need precise boat positioning relative to whales — consider the [dedicated humpback tour](/humpback-whale-watching-uvita/) for a more focused, smaller-group experience