El Niño Effect on Coffee Yield
Global green-bean prices have hit record highs since 2023, driven by a perfect brew of climate stress, supply chain disruptions, and surging global demand.
Multi-year droughts in Brazil and to a lesser extent Vietnam, the world's largest producers, have reduced yields and degraded bean quality. Rising temperatures, erratic rainfall, and increasing pest pressure continue to threaten every major growing region. Elevated temperatures are forcing Coffea arabica cultivation to higher altitudes and shrinking the supply of premium beans.1 Coffea canephora, or Robusta, has grown from 28% of global production in the early 1990s to 44% in 2023, and researchers are working to lift its cup quality.2 Both remain vulnerable to climate extremes.3
Demand is accelerating. Consumption is climbing sharply in emerging markets like China and the global shift toward specialty coffee is squeezing already-limited supplies.4,5 New European anti-deforestation rules, geopolitical trade dynamics, and shipping disruptions add fresh uncertainty. Because coffee trades on futures markets, these overlapping risks get priced in fast and amplify volatility across the entire system.6
Global production
Brazil produced almost 43.7 million 60-kg bags of Arabica, roughly 45% of global supply in 2023.7
Global production conceals a fragile workforce: around 60% of coffee is grown by an estimated 12.5 million smallholders working farms of 50 acres or less. Around 44% of coffee farmers live below the World Bank's poverty line, leaving them with limited resources to adapt to a changing climate.8
Climate change is expected to reduce the suitability and productivity of coffee-growing regions at lower altitudes, especially below 1,000 metres, across major producing regions such as Brazil, Nicaragua, Colombia, and Southeast Asia. Brazil faces a particular challenge: with little high elevation land available, its extensive low-lying Arabica regions are projected to face substantial losses by 2050.9 In Ethiopia, the impacts are already visible, with 80% of coffee farmers reporting significant production irregularities in recent years.10
Consumption
The world consumed 10.3 million tonnes of coffee in 2023. Global coffee consumption grows steadily by around 1-2% each year by volume, while the value of the coffee market is rising faster at over 5% each year as consumers spend more on premium and convenience coffee products.11
While the United States and the European Union together account for the bulk of global coffee consumption, countries across Asia, Africa, and the Middle East are home to large and growing populations of coffee drinkers.
Nowhere is the shift more striking than in China: long associated almost exclusively with tea, it has become one of the fastest-growing coffee markets, driven by a new generation of urban consumers, app-native consumer behaviour, and rapid expansion of domestic chains. Rising consumption is also evident across India, Indonesia, the Gulf, and sub-Saharan Africa. China is reshaping global coffee trade from both ends: as a major coffee buyer and a growing exporter of affordable café equipment to emerging markets.12,13
A rising demand curve and a contracting supply curve has one predictable outcome: upward pressure on prices and greater volatility along the way.
Current Climate
Anomalous sea surface temperatures
An El Niño has returned
A strong or very strong El Niño is emerging,14 with ocean surface temperatures in the central to eastern tropical Pacific Ocean at least 2°C above average. After years of La Niña priming the system, this event could rank among the most intense on record; only five comparably strong El Niños have occurred since 1950, the most recent in 2015/16.
El Niño is a climate pattern in which unusual trade winds trigger slow internal ocean waves that pile up vast amounts of heat (roughly 1015 kJ, equivalent to several million Hiroshima bombs) in the eastern Pacific. It can persist for over a year and is the most predictable large-scale seasonal climate pattern; when an event is very strong, its influence tends to dominate other patterns. Its effects typically lag the peak of the event (November to December) by about three months.
El Niño events can trigger climate regime shifts: abrupt transitions in sea surface temperature, air temperature, and soil moisture. In each historical case, the event created a new normal that lasted for years after the El Niño itself had passed. Strong El Niño events increase the likelihood of such shifts by roughly 20% compared to other years.15
El Niño Reshapes Global Coffee Risk
No two El Niños are identical, but the broad pattern involves hot, dry conditions across Southeast Asia. Robusta-producing origins, Vietnam and Indonesia, typically bear the heaviest burden. El Niño arrives during Indonesia's blooming phase and Vietnam's cherry-growth period. Minimum temperatures rise across the region, nights stay warmer through flowering, and rainfall is reduced during key monsoon periods.16 Historically, El Niño events have tended to raise Robusta prices while lowering Arabica prices.17,18
Warmer, drier conditions pull moisture from coffee leaves and soil aggressively, measured as vapour pressure deficit or the atmosphere's "thirst". Where rising temperatures are not offset by rainfall, vapour pressure deficit quickly crosses yield-limiting thresholds. Arabica yields, for instance, fall sharply above a vapor pressure deficit of roughly 0.82 kPa during fruit development, a threshold that Kenya, Mexico and Tanzania are already exceeding on average. Global heating beyond 2°C is expected to frequently exceed vapour pressure deficit thresholds. If global temperatures rise from 2°C to 3°C, countries such as Peru, Honduras, Venezuela, Ethiopia, Nicaragua, Colombia, and Brazil will be pushed beyond viable coffee-growing conditions.19,20
Vietnam and Indonesia's warm, moisture-stressed, rain-dependent growing regions are also highly sensitive to drought. Vietnam's irrigation provides some protection; Indonesia's smallholders have far less. Vietnam's exposure also depends on the Indian Ocean Dipole: a climate pattern in which the western Indian Ocean warms relative to the east, when positive, it brings cooler, wetter conditions that can partially offset El Niño drying.16
Central and South America experience variable weather. Much of Colombia and Guatemala experience drier conditions during an El Niño, with reduced soil moisture across growing regions. Up to a point, this can be beneficial: increased sunlight and moderate drying can stimulate flowering and intensify flavour. But when El Niño pushes conditions past a threshold into drought, plant growth suffers. La Niña brings the opposite problem: yields decline through excess cloud cover, reduced sunlight, and higher disease pressure. Colombia's mountainous geography means local outcomes vary considerably by elevation and slope.21
Wetter conditions bring different risks. Lower vapour pressure deficit reduces atmospheric water stress, but creates the warm, humid conditions in which fungal diseases thrive. Coffee leaf rust (Hemileia vastatrix) is a major cause of coffee yield and quality losses in Brazil, and requires fungicide spray applications every season.22 Its spread tracks daily minimum temperatures, relative humidity, and how long leaves stay wet.23 Unlike drought, which shows up clearly in harvest numbers, rust quietly erodes quality and adds significant cost.
Because El Niño influences Brazil, Vietnam, Colombia, Peru, Mexico, and Indonesia through the same interconnected atmosphere, a strong event can stress several regions at once, leaving few places to turn for compensating supply.
Brazil's relationship with El Niño is complex
El Niño years raise temperatures and water deficits across most of Brazil's major coffee states.24 Reduced rainfall lets more buds reach dormancy together, so that when rain finally returns it triggers a single, concentrated bloom. Too much rain or severe drought can produce premature 'star flowers' that open without proper rehydration.25
Geographically, the picture is not uniform: southern, eastern, and coastal Brazil often receive above-average rain in some El Niño years, and the south reacts less strongly to El Niño-driven climatic changes than other origins.16 So Brazil can sometimes act as a partial buffer for global supply during strong El Niño events.
The 2015/16 and 2023/24 events offer useful benchmarks. Each struck a system in a different state of health. The 2015/16 El Niño compounded the effects of the 2014/15 drought, particularly in Espírito Santo, where roughly 90% of irrigation-dependent plantations in the northern, northeastern, and northwestern parts faced sudden hydraulic deficit. Elevated temperatures did more damage than the rainfall decline alone. Dry months through the flowering and fruit-development window cut conilon robusta output by nearly 40%.26
The 2023/24 El Niño struck a system under even more prolonged stress. Since 2014, rising temperatures and recurring rainfall deficits had left much of Brazil in a near-permanent hydraulic deficit. Successive shocks: the 2020 drought, the July 2021 black frost, and droughts in 2016/17, 2019/20, and 2023, disrupted the normal biennial cycle as farmers replanted large areas off-schedule. Many farms then went 120–130 days without meaningful rain during the 2024 growing phase. Combined with extreme heat during the flowering window, these conditions pushed much of the Arabica belt into stress flowering: trees prioritising leaf regrowth rather than fruit, and cannibalising the next crop.25
The July 2021 'black frost': pre-dawn temperatures of −1 to −2 °C across Minas Gerais and São Paulo, the worst since 1994, killed unhardened young plants and extended recovery periods by several years.27 Pruning after frost costs one to two years of regrowth, forcing an artificial, extended 'off' cycle. A severe hailstorm in 2025 damaged around tens of thousands of hectares of coffee farms in Minas Gerais. While national production remained largely unaffected, the event highlighted the growing frequency of climate-related extremes.
An El Niño in late 2026 and extending into early 2027 may lower frost risk in Brazil but increase temperatures during flowering and grain filling, while also altering rainfall patterns. Together, these conditions could place further pressure on the size and quality of the 2027 harvest.
The infographic below illustrates the phenological cycle of Arabica coffee in Brazil and shows whether deviations in key climate variables from their optimal ranges during the 2015/16 and 2023/24 El Niño events were favourable or unfavourable to crop development in Minas Gerais, Brazil's largest Arabica-producing state.
What Makes 2026 Different
Background warming is raising baseline temperature and vapour pressure deficit stress across coffee growing regions, so that even a moderate El Niño can now push conditions past thresholds once reached only by the most extreme events. The 2026 El Niño is forming in an atmosphere hotter and more carbon dioxide-laden than any in the history of coffee cultivation. Climate change is also increasing the swings of impact, with rainfall variability of El Niño and La Niña events projected to increase.28,29
The nature of drought is changing. Its main driver is shifting from too little rain to too much atmospheric evaporative demand: record land-surface temperatures evaporate water so fast that severe soil-moisture drought can develop even when rainfall is only slightly below average. Drought can inflict up to 80% productivity loss in the driest years, especially in marginal, non-irrigated coffee growing regions.30
In a warmer world, extremes are faster and more damaging. For coffee, adaptation will require redesigning farm microclimates through shade architecture, improved soil and water practices, agroforestry and more heat-tolerant coffee varieties.31
Protecting existing forests in coffee landscapes secures the local water cycles and biodiversity that the crop depends on.32,33Encouragingly, weather conditions this year were favorable and have supported production recovery, with strong pre-El Niño harvests expected in Brazil and Vietnam. No significant cold spells have been reported so far. While this relatively strong starting point provides a useful buffer going into a warmer and more variable climate, risk remains as El Niño unfolds.
How we measure risk
The coffee industry is feeling the effects of unpredictable weather patterns across its entire value chain, from producers to consumers. Underlying all of this is a structural vulnerability: Brazil and other countries have been expanding coffee onto marginal, warmer, drier land where water shortage and unfavourable temperatures increasingly constrain yields. To keep thriving, the industry must collectively prioritize sustainability and resilience.
Uncharted Waters' Digital Twin integrates real-time climate data with crop and trade modeling. By exploring data from coffee-producing regions around the world, our dashboard makes interconnected climate risks visible.