Q COSTARICA — The national weather service, Instituto Meteorológico Nacional (IMN), forecasts that the El Niño phenomenon will maintain strong intensity during the coming months and will reach a very strong category between October of this year and March 2027.
According to the most recent update of the Sistema de Alerta Temprana del fenómeno ENOS —Early Warning System of the ENOS phenomenon, released on June 10, Costa Rica will remain under the effects of El Niño for the remainder of 2026 and even into the first months of next year.
This was explained by Karina Hernández, Climatology Coordinator at the IMN, who explained that the productive sector is constantly informed in advance so that they can take into account the consequences of this meteorological phenomenon.
Furthermore, the IMN indicated that in the near future, rainy conditions will begin to decrease in several regions of the country during the coming weeks due to the gradual onset of the midsummer drought, a phenomenon characteristic of the rainy season that reduces rainfall and increases the intensity of the trade winds.
El Niño is a natural climate phenomenon characterized by the anomalous warming of the surface waters of the central and eastern equatorial Pacific Ocean. This warming alters atmospheric circulation globally, drastically modifying rainfall and temperature patterns across the planet.
How does it work?
- Weakening winds: The trade winds, which normally push warm water toward Asia, weaken or change direction.
- Heat displacement: Warm water accumulated in the western Pacific moves toward the coasts of South America.
- Atmospheric change: Heat from the ocean is released into the atmosphere, altering the global climate and temporarily raising the planet’s temperature.
Main effects worldwide
- South America (West Coast): Causes torrential rains, flooding, and landslides in coastal areas of Peru, Ecuador, and Colombia. Drastically reduces commercial fishing due to the lack of nutrients in the warm water.
- Central America and the Caribbean: Generates severe droughts, decreases in reservoir levels, and intense heat waves.
- Amazon and Northeast Brazil: Produces extreme droughts that increase the risk of forest fires.
- Asia and Oceania: Weakens monsoons, causing severe recurring droughts in countries such as India, Thailand, Indonesia, and Australia.
- North America: Causes wetter and colder winters in the southern United States and drier and warmer conditions in the north.
The phenomenon occurs cyclically and irregularly, approximately every two to seven years: The active phases usually last between 9 and 12 months, typically reaching their maximum intensity between November and January.
El Niño (Christ Child) was named by Peruvian fishermen in the 17th century, because the warming of the water was usually noticeable near the Christmas holidays.
La Niña is so named simply because it is the opposite phenomenon. They don’t necessarily alternate and are usually identified by the sea surface temperature in the central and eastern Pacific. During El Niño, these waters are warmer, and, in the case of La Niña, they are cooler