CoffeeNetwork (New York) - El Niño and La Niña are opposite phases of what is known as the El Niño-Southern Oscillation (ENSO) cycle. La Niña is sometimes referred to as the cold phase of ENSO and El Niño as the warm phase of ENSO. These deviations from normal surface temperatures can have large-scale impacts not only on ocean processes, but also on global weather and climate, and thus, global coffee production.
Global climate La Niña impacts tend to be opposite those of El Niño impacts. In the tropics, ocean temperature variations in La Niña also tend to be opposite those of El Niño.
During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest.
Many of the global weather forecasters are now in a state of La Niña “watch,” with La Niña favored to develop during July-September (65% chance) and persist into the Northern Hemisphere winter 2024-25 (85% chance during November-January), according to the latest NOAA forecast.
How this will affect global coffee production will have a lot to do with timing and severity. The severity of the event can have different implications on output, where, during moderate and severe conditions, average world coffee production drops by around 1%, while weak conditions increased output by 1.6%.
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Major Effects of Recent Strong La Niñas
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- Drier than normal weather on the west coast of South America
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- Heavy rainfall in Far East Asia and parts of Australasia
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- Drier conditions in the south of Brazil and Argentina
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- Wetter than normal conditions in Colombia and Central America
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- Drier than normal weather on the US West Coast
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- A colder than normal winter in the Northern Hemisphere
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In general, the risk of frosts or more intense cold in Brazil increases during La Niña years, Ludmila Camparotto, Agrometeorologist with Rural Clima, told CoffeeNetwork. “However, this year, we do not see risk of intense cold occurring in coffee growing areas,” she said.
This is most likely due to the proximity to the solar minimum.
How Solar Minimums Come Into Play
Solar minimums are a period of least solar activity in the 11-year solar cycle of the sun. The solar minimum years can be classified as the periods with the least amount of “dark blotches” that appear on the surface of the sun.
For Brazil winter weather, 70-80% of frost events have occurred within 2 to 3 years of a solar minimum. The last solar minimum was in 2020, and the last major frost event that damaged the Brazilian coffee crop was in 2021, according to Drew Lerner, President of World Weather Inc.
“While the biggest threat of Brazilian frost are the years close to a solar minimum, we are actually at a solar maximum right now,” Lerner explains, detailing that this will occur at the end of 2024 and into early 2025. “While there have been one or two exceptions in the history book, generally years closer to a solar maximum have little risk of damaging frost.” He notes that there could be some cold fronts that come out of Argentina throughout the winter season, however, they should stop short of getting into coffee territory.
What Makes This La Niña Different
This La Niña is wedged between other ENSO events. We are coming into La Niña from El Niño, which is a very different scenario than the last La Niña event, which occurred in 2020. During that time, La Niña was the start of the ENSO events and entered at the beginning of the 22-year solar cycle. According to Lerner, La Nina’s that occur this way are destined to prevail for multiple years and will be more impactful.
Now, coming into this La Niña from El Niño, the atmosphere will take time to adjust from one bias to another. When we saw transitions like this in the past (La Niña to El Niño and back to La Niña) the event has been very weak and does not have the same impact on world weather as it would if it was a more traditional event.
For Brazil, there can still be some delay in initial rains across the coffee belt. The initial rains in late September/early October may be sporadic and lighter but not dry biased, like what we saw in other years, and not threatening to coffee. La Niña would induce better rain in November and December and should help a supportive environment during flowering, the most critical time for coffee.
Sentiment, however, is mixed as to how this rainfall would impact the uniformity of flowering. “The sporadic rains may mean an uneven flowering in terms of different regions flowering at different times, but ultimately, all of the coffee belt will receive enough rainfall for a healthy flowering,” Lerner told CoffeeNetwork. However, Camparotto thinks the later start to the rainfall could favor a more uniform flowering, “but this could be detrimental if rains in August and September cause flowers to open followed by a dry period,” she said. La Niña is expected to weaken early in 2025, so the end of the season should be typical. Temperatures are expected to return to normal levels after July/August and should not be as high as they were in 2023, according to Clima Rural’s forecast models.
Colombia’s flowering of the main crop in 2025 is expected to be fairly normal. And with the adverse weather mostly behind us, the mid-crop will finish out with better weather.
Central America could still see flooding rains over these next few weeks, but for this region, the flowering season occurs in early 2025 so there wouldn’t be much of an impact. La Niña could bring some additional moisture during off-season. Overall, the expectation is that this region will be coming out of drought conditions and go into flowering season with a normal environment, favorable for the 2025 crop.
Things are looking up for Vietnam, with extended forecasts anticipating better weather than has been observed for the last few months. La Niña could bring abundant rainfall during the off-season for the coffee crop, during the 4th quarter of this year. This could bring some disruption to harvesting activities, but should not impact yields. When rains come back in 2025, La Niña will be diminishing by about that time, which should lead to a successful flowering season…better than this year. Indonesia should also be helped by La Niña and have a normal season.
The aftermath of El Niño is still showing its impact on Africa. With the shift to La Nina, however, the expectation is that the mid-crop would do much better with more rainfall. Flowering will be healthier than the main season crop which just flowered. The main crop, which flowers in February/March will have a normal start to the rainy season.
Alexis Rubinstein
La Niña, Brazil Frost Threats and the Global Coffee Crop 
