El Niño Deepens the Contrast Between Drought and Heavy Rain Across the Country

The effects of El Niño are creating sharply different weather conditions across Costa Rica. While much of the Pacific is experiencing persistent rainfall deficits and above-average temperatures, the Caribbean is seeing significantly wetter conditions.

Recent forecasts from Costa Rica’s National Meteorological Institute (IMN) indicate that this pattern is expected to continue, with particularly dry conditions across the Pacific and wetter conditions in parts of the Caribbean. The World Meteorological Organization also reports that El Niño is expected to strengthen during August–October 2026 and influence rainfall patterns in different regions.

The Pacific Faces an Expanding Rainfall Deficit

The current dry conditions extend across the Pacific slope, the Central Valley and parts of the western Northern Zone. According to recent reporting based on IMN data, the North Pacific could finish August with rainfall up to 80% below normal.

The Central Pacific, South Pacific and Central Valley could see deficits of around 60%, while the western Northern Zone could experience reductions of approximately 40%.

The drought situation has also expanded compared with earlier months, bringing additional areas of the country into the affected zone.

A Much Wetter Pattern in the Caribbean

The Caribbean is experiencing a very different situation.

While the Pacific is facing prolonged dryness, parts of the Caribbean are receiving rainfall above their usual levels. This contrast is one of the most noticeable effects of the current climate pattern.

The situation highlights how the same weather phenomenon can produce very different impacts depending on the region of the country.

Why Does El Niño Create Such Different Conditions?

El Niño occurs when ocean temperatures in the central and eastern tropical Pacific become unusually warm, influencing atmospheric circulation and rainfall patterns around the world.

The World Meteorological Organization says the developing 2026 El Niño is expected to contribute to above-normal temperatures and significant changes in precipitation patterns during the August–October period. Some areas are therefore more exposed to drought, while others can experience wetter-than-normal conditions.

For Costa Rica, the Pacific is particularly vulnerable to dry conditions during El Niño events, while the Caribbean can experience a very different rainfall pattern.

A Drought Does Not Mean There Is No Rain

Meteorological drought does not necessarily mean that an area receives absolutely no rainfall.

Short periods of heavy rain can still occur, but they may not be enough to compensate for a prolonged rainfall deficit. What matters is the accumulated difference between observed precipitation and historical averages over time.

This is why a region can experience occasional storms while still remaining classified as being under drought conditions.

Potential Effects on Water and Agriculture

If dry conditions persist, their effects can extend beyond rainfall measurements.

Agriculture is particularly sensitive to prolonged periods of low precipitation and high temperatures. Reduced soil moisture can affect crops and pasture, while farmers may face greater pressure on water resources.

Costa Rica’s electricity system can also be affected because a significant share of the country’s electricity generation comes from hydropower. Lower rainfall and reduced reservoir inflows can therefore create additional pressure on electricity production. Recent reporting has already highlighted concerns about the effects of the current drought on agriculture and electricity generation.

Higher Temperatures Add to the Pressure

The rainfall deficit is occurring alongside elevated temperatures.

The World Meteorological Organization expects El Niño to contribute to above-normal temperatures across much of the world during the August–October 2026 period.

For Costa Rica, the combination of heat and reduced rainfall can increase evaporation and further reduce the amount of water available in soils and natural systems.

Different Risks on Each Side of the Country

The current situation demonstrates why Costa Rica’s weather conditions cannot be described uniformly.

In the Pacific, the main concerns are prolonged dryness, high temperatures and their potential effects on agriculture, water availability, ecosystems and electricity generation.

In the Caribbean, heavier rainfall can instead increase the risk of saturated soils, river flooding and landslides in vulnerable areas.

The result is a striking contrast: drought in some regions while others are experiencing significantly wetter conditions. Recent weather events have already shown how quickly heavy rainfall can affect the Caribbean and Northern Zone.

Monitoring El Niño in the Coming Months

The evolution of El Niño will remain important for Costa Rica throughout the second half of 2026. International forecasts indicate that the phenomenon is expected to strengthen during August–October, making continued monitoring of rainfall and temperatures particularly important.

For Costa Rica, the coming months will be closely watched because the effects of prolonged dryness or excessive rainfall can extend beyond weather conditions, influencing agriculture, water resources, ecosystems and communities.