Q COSTA RICA — Extreme rainfall variations in Costa Rica during July left their mark on the country, with large areas experiencing meteorological drought and others with record-breaking surpluses.
The national weather service, Instituto Meteorológico Nacional (IMN), confirmed that the effects of El Niño caused an uneven redistribution of precipitation, generating deficits of up to 58% in the Pacific and Central Valley regions, while the Caribbean and the Northeastern Zone experienced increases of up to 70%.
The phenomenon was reflected in the records of nine weather stations that reported the lowest rainfall levels in July, such as Pavas in San José, with only 4.8 millimeters accumulated throughout the month. In contrast, Cariari de Pococí, on the Caribbean slope, reached a maximum of 1,274.6 mm, driven by two rain events that occurred at the beginning and end of the month.
July’s weather patterns coincided exactly with the warning issued by the IMN at the beginning of the month regarding the strengthening of the midsummer drought, which was expected to reduce rainfall in the Pacific and Central Valley regions, while the Caribbean would remain much rainier from mid-month onward.
The IMN warned that the rainfall deficit in the Central Valley, the Northwest Zone, and much of the North Pacific already meets the criteria for meteorological drought. Furthermore, other areas such as the Nicoya Peninsula, the Osa Peninsula, and parts of the Central Pacific could also experience this condition if the trend persists in the coming weeks.
Karina Hernández, a specialist at the IMN, explained that the main problem with El Niño lies in the way it modifies rainfall distribution: “The most complicated thing about El Niño is the distribution of rainfall. It can rain very heavily in a few days and then go several days with practically no precipitation. Furthermore, it generates a deficit in the Pacific and Central Valley, but increases rainfall in the Caribbean.”