La Niña 2025 arrives late but will likely persist until spring. The cold phase of the natural climate phenomenon known as El Niño causes temperature fluctuations and changes in the atmosphere. Its effects cannot be separated from those of climate change.
We’ve grown accustomed to living with record-breaking temperatures. High temperatures and heat waves make headlines time and again, month after month, turning the exceptional into the normal. Every summer, record temperatures have been broken for as long as records have been kept .
It’s true that recent years have been marked by the presence of El Niño, the warm phase of a recurring, natural phenomenon in the tropical Pacific Ocean. And now, after a few months of uncertainty and with some delay, its cold phase, La Niña, appears to be knocking at the door, according to the latest forecasts from the World Meteorological Organization (WMO). Does this mean the planet’s temperature is about to drop? And what consequences will this have on weather patterns in Latin America, one of the regions most influenced by the El Niño-La Niña pairing?
What is the 2025 La Niña phenomenon and how will it affect the global climate?
The El Niño-Southern Oscillation (ENSO) is a natural climate phenomenon that causes fluctuations in the temperature of the equatorial Pacific Ocean and changes in the atmosphere. It has been recognized for a long time, and its different phases have been accurately predicted since 1986 using thousands of buoys and temperature sensors spread across the oceans. This phenomenon consists of a phase with higher-than-normal temperatures ( El Niño ), a neutral phase, and a phase with lower-than-normal temperatures ( La Niña ). In recent months, El Niño has dominated the Pacific. The WMO now indicates a 60% chance of La Niña occurring from June-July onwards, and a 70% chance of La Niña occurring from August onwards.
“The forecasts are becoming increasingly clear: La Niña is very likely to develop during the summer and autumn and continue at least until the end of the year. It usually lasts longer than El Niño, but we still don’t know exactly what will happen this year; there is uncertainty surrounding the strength and duration of the next La Niña event,” explains Álvaro Silva, a WMO climatologist. “Swinging from one to the other in a short period of time is normal, especially considering we’re coming off a very strong warm spell. It’s happened before, and it’s natural.” However, this year it arrived somewhat late and is expected to be weaker than in previous years.
Effects of La Niña 2025: global temperature, storms, and droughts
Globally, El Niño events can produce an increase in average surface temperatures, while La Niña events have a cooling effect, according to the WMO. However, the influence of this phenomenon is limited, while the overall global warming trend is increasingly intense and evident. “The effects of climate change are clear, regardless of El Niño or La Niña. The last nine years have been the warmest on record, despite the fact that La Niña has persisted for a prolonged period in the Pacific in recent years,” Silva notes. “We can expect a slight decrease in temperature compared to what would happen without La Niña, but it won’t be significant.”
According to the expert, El Niño and La Niña influence weather patterns across the planet, and their effects cannot be separated from those of climate change. Therefore, temperatures in Latin America are expected to remain higher than normal in the coming months.
Furthermore, El Niño and La Niña also have a clear effect on hurricanes. While El Niño and La Niña typically have high hurricane activity in the Pacific and low hurricane activity in the Atlantic, La Niña is the other way around.
The countries most affected by La Niña
The cooler-than-normal surface waters of the tropical Pacific have global effects. These are the countries and regions typically most affected:
- Countries in southern and eastern Africa. In the south of the continent, La Niña is often accompanied by heavier than normal rainfall, while in the east it is associated with intense droughts. One of the most recent La Niña episodes caused one of the worst famines on record in the Horn of Africa.
- Australia and the western Pacific. In this region, La Niña is associated with heavier and more intense rainfall.
- Central American countries. In most of Central America, and particularly along the Caribbean coast, La Niña brings wetter-than-normal conditions and an increased occurrence of extreme events such as hurricanes.
- Colombia, Ecuador, and the central Andes. These countries also often experience torrential rains during the cold phase of ENSO.
- Peru, Bolivia, Argentina, Chile, and central and southern Brazil. In contrast, the rest of South America tends to experience worsening droughts and high temperatures. During one of the most recent La Niña episodes, for example, Argentina suffered a drought that reduced its agricultural exports by up to 50%.
The La Niña phenomenon in Colombia
In Colombia , the effects of La Niña are often significant, causing increased rainfall, flooding, and landslides, especially in the Andean, Orinoco, and Amazon regions. Furthermore, the Magallanes and Cauca rivers often burst their banks, affecting thousands of people and damaging infrastructure and crops.
This phenomenon also has a strong impact on the economy and public health. In the agricultural sector, excess humidity harms crops such as coffee, rice, and bananas, in addition to promoting the spread of pests and diseases. Regarding infrastructure, heavy rains damage roads, bridges, and homes, hampering mobility and increasing repair costs.
Colombia has experienced several severe La Niña episodes. Preventive measures have been implemented to mitigate its effects. However, risk management remains key to minimizing the impact of this phenomenon in the country.
How long will La Niña last in 2025?
The relationship between climate change and La Niña, although close, is not fully understood, which complicates medium-term forecasts. “There is no consensus in the scientific community about the influences of climate change on La Niña and El Niño, but what we are certain of, in line with what has been published by the IPCC, is that the climatic impacts of both phenomena are being exacerbated by climate change,” explains Álvaro Silva. “We know that when we experience El Niño or La Niña conditions, their impacts will be much more significant in terms of frequency and intensity.”
As for what we can expect regarding the duration and intensity of the La Niña that is beginning to develop, it is expected to last until April. “We know that La Niña typically lasts longer than El Niño and that in recent decades we have had several events that have lasted several years,” concludes the WMO researcher.
