Sea temperature in Costa Rica
Live water temperatures and swimming conditions across 20 beaches on the Costa Rica coast.
Best time to swim in Costa Rica
The sea in Costa Rica peaks in July, when the water averages around 23°C.
The main swimming season runs from January – December, when surface temperatures stay comfortable for extended sessions.
On average, 12 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
The coldest month is typically January at around 20°C, when cold-water swimmers dominate the coast.
Costa Rica sea temperature history
Long-term climatology for Costa Rica shows an annual mean sea temperature of 21°C, ranging from 20°C in winter to 23°C at the summer peak.
The seasonal swing is roughly 3°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Costa Rica, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Values are area averages; individual beaches vary by exposure and depth.
Costa Rica sea temperature: frequently asked questions
What is the warmest month to swim in Costa Rica?
July is the warmest month in Costa Rica, when the sea averages about 23°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Costa Rica?
The coldest month in Costa Rica is typically January, when the water averages around 20°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Costa Rica without a wetsuit?
The main swimming season in Costa Rica runs from January – December — about 12 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Costa Rica?
Outside peak summer the water in Costa Rica drops toward 20°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Costa Rica?
The long-term annual mean sea temperature in Costa Rica is about 21°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Costa Rica?
The live reading at the top of this page shows the current sea temperature in Costa Rica, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Costa Rica sea temperature by month
Average sea temperatures around Costa Rica for every month of the year, based on long-term Open-Meteo marine climatology.
| Month | Average sea | Swimming comfort |
|---|---|---|
| January | 20.0°C | Swimmable, refreshing |
| February | 20.0°C | Swimmable, refreshing |
| March | 20.0°C | Swimmable, refreshing |
| April | 20.0°C | Swimmable, refreshing |
| May | 21.0°C | Pleasant swimming |
| June | 22.0°C | Pleasant swimming |
| July ⭐ | 23.0°C | Pleasant swimming |
| August | 23.0°C | Pleasant swimming |
| September | 23.0°C | Pleasant swimming |
| October | 22.0°C | Pleasant swimming |
| November | 21.0°C | Pleasant swimming |
| December | 20.0°C | Swimmable, refreshing |
Monthly figures are modelled climatology averages, not live readings. How accurate is our data?
Warmest beaches in Costa Rica right now
| Beach | Region | Sea | Swim score |
|---|---|---|---|
| Cahuita Beach | Limon | 29.7°C | Excellent |
| Playa Cocles | Limón | 29.6°C | Excellent |
| Punta Uva Beach | Limon | 29.6°C | Excellent |
| Puerto Viejo Beach | Limon | 29.5°C | Excellent |
| Playa Dominical | Puntarenas | 28.7°C | Excellent |
| Playa Hermosa CR | Guanacaste | 28.5°C | Excellent |
| Playa Nosara | Guanacaste | 28.5°C | Excellent |
| Playa Espadilla | Puntarenas | 28.5°C | Excellent |
| Montezuma Beach | Puntarenas | 28.4°C | Excellent |
| Playa Manzanillo | Limon | 28.4°C | Excellent |
| Santa Teresa Beach | Puntarenas | 28.2°C | Excellent |
| Playa Samara | Guanacaste | 28.0°C | Excellent |
| Playa Uvita | Puntarenas | 28.0°C | Excellent |
| Playa Flamingo | Guanacaste | 27.9°C | Excellent |
| Mal Pais Beach | Puntarenas | 27.9°C | Excellent |
| Manuel Antonio Beach | Puntarenas | 27.9°C | Excellent |
| Playa Avellanas | Guanacaste | 27.8°C | Excellent |
| Playa Hermosa Guanacaste | Guanacaste | 23.6°C | Excellent |
| Playa Tamarindo | Guanacaste | 23.3°C | Excellent |
| Playa Conchal | Guanacaste | 23.1°C | Excellent |
Sea temperature in Costa Rica — FAQ
How warm is the sea in Costa Rica in September?
The sea off Costa Rica averages about 23.0°C in September, based on long-term monthly averages for this coast.
When is the best time to swim in Costa Rica?
Costa Rica is warmest in July (around 23.0°C) and coldest in January (around 20.0°C). There are typically 5 months a year when the water sits above 22°C.
What is the average yearly sea temperature in Costa Rica?
Across all twelve months, the sea in Costa Rica averages about 21.3°C.
Do you need a wetsuit to swim in Costa Rica?
In peak season (around July, ~23.0°C) most swimmers are comfortable without a wetsuit. Outside summer, when the water drops toward 20.0°C, a 3/2mm to 5/4mm wetsuit is recommended.
Which beach in Costa Rica has the warmest sea right now?
Puerto Viejo Beach typically has the warmest sea in September, while Playa Hermosa Guanacaste is the coolest of the featured beaches. Live readings for every beach are listed on this page.