Costa Rica is bracing for an extended El Niño event that meteorologists now expect to grip the country from June through the second half of 2026 and persist into the early months of 2027, prompting authorities to activate a national contingency plan covering water supply, electricity, agriculture and wildfire risk.
The Instituto Meteorológico Nacional (IMN) has escalated its El Niño classification from “surveillance” to “advisory,” meaning forecasters now consider the development of the phenomenon highly likely rather than possible. The updated outlook is notably more severe than projections released as recently as April. The IMN now estimates rainfall deficits of up to 50 percent in some regions and temperatures running as much as 2 degrees Celsius above normal, compared with earlier estimates of 10 to 30 percent rainfall reduction and warming of 0.5 to 1 degree.
“Those deficit conditions are now expected to be worse than they were a month ago,” Karina Hernández, head of the IMN’s Climatology Unit and director of the country’s ENOS Phenomenon Consultative Commission, said. She added that under the current outlook, “we would be under the effect of that El Niño throughout the second half of 2026 and possibly extending into the beginning of 2027.”
The IMN forecast aligns well with the latest from the United States National Oceanic and Atmospheric Administration (NOAA), which puts the probability of El Niño persisting through February 2027 at 96 percent. The North American Multi-Model Ensemble favors El Niño developing within the coming month and continuing through the Northern Hemisphere winter of 2026 to 2027.
Forecasters expected Costa Rica’s 2026 rainy season to begin at least 15 days later than usual and to start irregularly. The Pacific slope, particularly Guanacaste, will see the sharpest impact, with the Central Pacific also exposed. The Caribbean slope, which typically experiences increased rainfall during El Niño events, is already running a precipitation deficit accumulated during the first part of the year, complicating the regional outlook. Intensity is being compared by the IMN to the 2014 to 2015 El Niño event, though forecasters caution that significant uncertainty remains around peak strength.
President Laura Fernández confirmed that an inter-institutional working group has been activated to coordinate the national response. The team brings together the Instituto Costarricense de Acueductos y Alcantarillados (AyA), the Comisión Nacional de Emergencias (CNE), the Instituto Costarricense de Electricidad (ICE), the Ministry of Environment and Energy (MINAE), the Ministry of Agriculture and Livestock (MAG) and the Ministry of Health. CNE president Alejandro Picado said that his agency has assumed leadership of the contingency plan, which is now active with its own timeline and budget.
The economic implications are already on the central bank’s radar. Banco Central de Costa Rica President Róger Madrigal López has indicated our country should expect an inflationary shock in early 2027 driven by El Niño’s impact on agricultural output and food prices. Reduced precipitation typically squeezes domestic production of staple goods, drives up the cost of livestock feed, and pressures the basic consumer basket. The Universidad Estatal a Distancia (UNED) has called for tighter coordination between academia, municipalities and the MAG to mitigate effects on smallholder farmers and rural communities.
“This event reminds us that water is a limited and vulnerable resource. It is not just a technical issue, but a challenge that directly affects daily life, from access to drinking water to food production,” said Melissa Chacón, a meteorologist with UNED’s Laboratory Program (Prolab). She urged households to adopt water and energy conservation practices and called community-level preparedness the strongest defense against climate impacts.
For those coming here to visit us, the most visible effects will likely include hotter and drier conditions in Guanacaste and the Central Pacific through the second half of the year, a delayed and uneven start to the green season, and the possibility of voluntary or mandatory water-use restrictions in affected areas. Authorities have asked the public to reduce consumption of both water and electricity as a precaution while the contingency plan rolls out.
