Costa Rica Weather Guide 2026 for Expats, Region by Region

COSTA RICA · WEATHER

Costa Rica weather has a rainy season from May to October and a dry season from December to March on the Pacific side. In 2026 a very strong El Niño, a warming of the Pacific Ocean, is making the coming dry season hotter and drier.

This guide uses the Instituto Meteorológico Nacional (IMN), Costa Rica’s national weather service, and NOAA, the US climate agency. It shows expats, retirees and remote workers which region suits them and what to plan for before the dry season starts.

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How Costa Rica Weather Works Through the Year

On the Pacific side the IMN describes a clear dry season from December to March, with April as a transition month. The rains settle in around May and last until October, with November again a transition.

September and October are the wettest months on the Pacific side, driven by storm systems and sea breezes. A short dip in rain in July and August, called the veranillo or canícula, comes when the trade winds strengthen.

The Caribbean slope has no defined dry season, because even its driest months bring 100 to 200 millimetres (4 to 8 inches) of rain. Its two relatively drier spells fall in February and March and again in September and October.

Cold fronts from the Northern Hemisphere reach Costa Rica between November and May, most often from November to March. They make December the wettest month on the Caribbean slope.

Every regional figure below is an IMN average for 1961 to 1990, the baseline period the agency publishes. Recent years can run warmer or wetter, so read the numbers as a guide to the pattern and not as a forecast.

Central Valley: Mild Days Around San José

The Central Valley holds the capital San José and the cities of Alajuela, Heredia and Cartago. The IMN puts the average temperature in its humid areas at 22°C (72°F), with about 2,300 millimetres (91 inches) of rain a year.

The western valley around San José is the wetter half, with about 2,300 millimetres a year. The eastern valley around Cartago gets about 1,700 millimetres (67 inches), but it has more rainy days.

The eastern valley still collects more than 100 millimetres (4 inches) of rain in the dry months from January to March. That Caribbean influence keeps the air humid and the heat milder than on the Pacific coast.

The western valley has an average daily high of 26.7°C (80°F) and a low of 16.5°C (62°F). Its low-lying western towns, such as Atenas and La Garita, have a drier Pacific-style climate.

For newcomers who want spring-like days without a sea breeze, this is the easiest region to live in. Our San José city guide covers the neighbourhoods and daily costs.

North Pacific: Hot and Dry Guanacaste

The North Pacific covers Guanacaste province and is one of the driest and hottest parts of the country. Only 4% of a normal year’s rain falls from December to March, and river flows drop through a dry season of five to six months.

The Tempisque lowland, the driest corner, gets about 1,700 millimetres (67 inches) of rain a year. Daytime highs there average 32°C (90°F), with nights near 22°C (72°F).

The coastal Nicoya peninsula gets about 1,900 millimetres (75 inches) a year, with highs around 33°C (91°F). The Guanacaste and Tilarán mountain ranges are wetter at about 2,200 millimetres, but far cooler at 25°C (77°F) by day and 17°C (63°F) at night.

Rain arrives in two periods, from May to August with 50% of the yearly total and from September to November with 46%. The northeast trade winds dominate the dry months.

Central and South Pacific: Beaches and Rainforest

The Central Pacific runs from Jacó to Dominical and includes Quepos and Manuel Antonio. Its valleys average about 3,500 millimetres (138 inches) of rain on 166 rainy days, with highs of 31°C (88°F).

The dry season here is short, from January to March, and brings only 4% of the year’s rain. The coastal valleys have almost no veranillo, because the mountains block the northeast trade winds.

The South Pacific is wetter still, with about 3,700 millimetres (146 inches) of rain a year on about 204 rainy days. Highs average 27.9°C (82°F) and lows 20.5°C (69°F).

Its dry spell runs from January to March and delivers only 11% of the yearly rain. The IMN found that 86% of the extremely dry years in this region coincided with El Niño.

Caribbean Slope and Northern Zone: Green and Wet

The Caribbean slope averages about 3,300 millimetres (130 inches) of rain a year, with up to 4,500 millimetres (177 inches) in the northeast. The south is drier, at 2,700 to 3,000 millimetres (106 to 118 inches), and its wettest stretch runs from November to January.

The Northern Zone, around the town of San Carlos, is the third wettest region. It gets over 3,200 millimetres (126 inches) a year on about 199 rainy days, in one long rainy period from May to January.

In past El Niño years the Caribbean slope has tended toward normal or wetter conditions, the IMN records show. This year its outlook for November to January points to about 30% less rain than normal.

The Northern Zone has no reliable El Niño pattern, but the IMN notes droughts near the Nicaraguan border in 1965, 1982 and 1997. Our guide to the San Carlos flood safety advisory shows the other side of that rain.

Costa Rica Weather Now: A Very Strong El Niño

El Niño is a warming of the central and eastern Pacific that shifts rain and heat around the world. The IMN says it occurs every two to seven years and that its effects usually last nine to 18 months.

On Thursday 8 October 2026 NOAA’s Climate Prediction Center kept an El Niño Advisory in effect, with the Niño-3.4 index at +2.1°C (3.8°F). Niño-3.4 is the temperature anomaly of a key patch of the central Pacific.

NOAA said a strong to very strong event is likely through January to March 2027, with a chance above 83%. Its next update is due on Thursday 12 November 2026.

The IMN says September ocean readings ran above those of the extreme events of 1997 and 2015. It expects a very strong phase through January 2027, then a gradual fade to a weak phase in June and July.

The effects are already visible. The IMN’s drought warning system still shows meteorological drought in the Central Valley and along the Pacific.

What to Expect From November to January

The IMN seasonal outlook, updated on Friday 16 October 2026, expects normal dry-season conditions on the Pacific slope and in the Central Valley. The Caribbean slope and the Northern Zone should see about 30% less rain than usual.

Temperatures should stay above normal everywhere. The outlook adds 1.5°C to 2°C (2.7°F to 3.6°F) on the Pacific slope and in the Central Valley, and 1°C to 1.5°C in the east.

The IMN expects the rains to end from 3 to 15 November in the North Pacific and 8 to 23 November in the Central Valley. In the Central Pacific it expects 13 to 30 November, and in the South Pacific around the end of the month.

Cold fronts should arrive at a normal rate, but with less rain and wind than usual. For Monday 2 November 2026 the IMN forecast a tropical wave bringing more rain, mainly at night, to the Caribbean slope and the Northern Zone.

The Atlantic hurricane season officially ends on Monday 30 November, according to the US National Hurricane Center. The IMN expects 9 to 12 named systems, and by 14 October there had been nine.

How to Choose Your Region

If you want a dry December through March, choose the Central Valley, the North Pacific or the Central Pacific. This year expect heat on top of the dryness, especially in Guanacaste.

If you want mild days and little air conditioning, choose the Central Valley or the mountain ranges. Retirees who struggle in the heat will find 22°C (72°F) far easier than the 32°C (90°F) of the Tempisque lowland.

If you do not mind daily showers and want green scenery, choose the Caribbean slope, the Northern Zone or the South Pacific. Ask any landlord about roof drainage, damp and water storage before you sign.

Visit in both a rainy and a dry month before you commit to a long lease. Remote workers should ask about backup power and a second internet connection, since storms can interrupt both.

Your First 90 Days Checklist

In week one, read the IMN’s regional climate page and note the rainy and dry months of your target region. Save the IMN forecast page and check it each morning.

In weeks two and three, ask your landlord about water supply, fans or cooling, and the condition of the roof. Set up a power and internet backup if you work remotely.

Before 30 November, watch the IMN warnings until the hurricane season ends. In December and January expect wind and more rain on the Caribbean slope when cold fronts arrive.

After NOAA’s next update on 12 November and again in December, check whether the El Niño outlook has changed. In month three decide whether the region suits you before you extend the lease.

What It Means for You

Newcomers arriving for the December to April peak season should expect a dry, dusty and warm start to 2027 on the Pacific side. Book housing early and plan for heat at midday.

Start with the Costa Rica news hub for current alerts. Our report on the El Niño drought alert in Guanacaste and the guide to the best places to live in Costa Rica add detail.

What Is Not Known

National park entry fees and booking rules for 2027 are not confirmed here, because the park agency’s site could not be read. Check them with the park service before you plan a trip.

How hot and dry the Pacific side will be in February and March is open. The exact day the rains end in each region is also open, and the IMN updates its outlook every month.

More: Costa Rica news in English, every day from The Rio Times.

Frequently Asked Questions

What is the weather in Costa Rica like in November?

November is the change between seasons. The IMN expects the rains to end between 3 and 30 November on most of the Pacific side, while the Caribbean slope stays wet.

When is the dry season in Costa Rica?

On the Pacific side and in the Central Valley the dry season runs from December to March. The Caribbean slope and the Northern Zone have no defined dry season.

How does El Niño affect Costa Rica in 2026 and 2027?

The IMN expects a very strong El Niño through January 2027, then a gradual fade to a weak phase by June and July. It points to a hotter, drier Pacific side and a drier Caribbean slope.

Which part of Costa Rica has the best weather?

The Central Valley is the mildest, with an average temperature of about 22°C (72°F). The North Pacific is the hottest and driest, with highs near 32°C (90°F) in the Tempisque lowland.

When is hurricane season in Costa Rica?

The Atlantic hurricane season runs from 1 June to 30 November. Costa Rica is not often hit directly, but passing systems and tropical waves can bring heavy rain.

Where can I find the official Costa Rica weather forecast?

The Instituto Meteorológico Nacional publishes daily forecasts, warnings, seasonal outlooks and monthly El Niño bulletins at imn.ac.cr. NOAA publishes the global El Niño update at cpc.ncep.noaa.gov.

Sources: IMN, Seasonal Outlook November 2026 to January 2027 (updated 16 October 2026), 16 October 2026; IMN, ENSO Bulletin October 2026, October 2026; IMN, Climate in Costa Rica: regional climates, 1961 to 1990 baseline, 2026; IMN, forecast of Monday 2 November 2026, 2 November 2026; NOAA Climate Prediction Center, ENSO Diagnostic Discussion, 8 October 2026; NOAA National Hurricane Center, Atlantic hurricane season dates, 2 November 2026.

This article was produced by The Rio Times’ automated newsroom system. How we use AI · Report an error · Editorial responsibility: Matthias Camenzind, Editor-in-Chief