In short
- El Niño and La Niña are opposite phases of ENSO, and in many tea regions they push rain and temperature in opposite directions.
- The clearest links are East Africa's short rains, the Indian monsoon, Indonesia, southern Africa and southern South America. Japan, Taiwan's high mountains and the Caucasus show little.
- Effects are tendencies, more likely in a strong event and never guaranteed. Local weather, altitude and flush timing matter too.
- The phase changes every year or few. This guide, and the weekly brief it feeds, work the same way in every phase.
ENSO right now
El Niño is in force. El Niño Advisory (NOAA CPC, 8 October 2026). El Niño continues to strengthen, with a strong-to-very strong El Niño likely through January-March 2027 (remaining greater than an 83% chance). The Niño-3.4 index is +2.1°C. Next NOAA update: 12 November 2026. Nilgiris, Kericho, West Java, Misiones, Western Uganda, Thyolo, Usambara, Nyungwe and Registro are in the part of the year that El Niño typically affects, so they are on the El Niño watch list when conditions allow.
This week's rain, temperature and forecast for every origin are in the Tea Weather Brief.
What are El Niño and La Niña?
ENSO (the El Niño–Southern Oscillation) describes swings in sea-surface temperature across the tropical Pacific and the atmosphere above it. NOAA tracks it with sea-surface temperature anomalies in the Niño-3.4 region of the equatorial Pacific. The Oceanic Niño Index (ONI) is the three-month average of that anomaly, and NOAA's Climate Prediction Center now uses the relative ONI (RONI), which expresses the same measure relative to the warming of the tropical oceans as a whole, for official monitoring. El Niño is the warm phase: an anomaly of +0.5°C or more with an atmospheric response typical of El Niño. La Niña is the cool phase: −0.5°C or less with a matching response. In between, ENSO is neutral.
The pattern swings back and forth every few years (NOAA puts the average at three to seven years) with no fixed schedule. An episode typically lasts nine to twelve months, although La Niña can last two years or more. Episodes tend to develop in spring, peak between November and February and fade the following spring or early summer. El Niño is often, but not always, followed by La Niña the next year, particularly if the El Niño is strong. That is why this guide is written for every phase, not only the current one.
NOAA announces the state of ENSO through its Alert System:
- El Niño Watch or La Niña Watch: conditions are favourable for that phase to develop within the next six months.
- El Niño Advisory or La Niña Advisory: that phase is observed and expected to continue.
- Final Advisory: issued after the phase has ended. With no alert active, ENSO is neutral.
How ENSO reaches tea
- Rain at the wrong time. ENSO shifts the strength of the monsoons and the timing of seasonal rains such as East Africa's October to December short rains. Too little rain stresses bushes and slows growth. Too much waterlogs estates, washes out roads and can dilute leaf quality.
- Temperature. Unusually warm spells can speed growth and change leaf quality. Colder winters raise frost risk at high elevation, for example on Himalayan first flush.
- Timing and logistics. Heavy rain interrupts plucking, transport and dispatch, so an effect can show up as delays before it shows up in volumes.
- Local weather, altitude and the timing of each flush all matter, and ENSO is only one influence. NOAA notes that impacts are more likely in a strong event, though never guaranteed.
At a glance: who gets wetter and who gets drier
The same pattern pushes some tea regions towards wetter weather and others towards drier, and usually the opposite way in the opposite phase.
| Where | In El Niño | In La Niña |
|---|---|---|
| East Africa short rains (Kenya, Uganda, Rwanda, Tanzania) | Typically wetter in October to December, raising waterlogging, road-access and leaf-quality risks. | Usually drier, which can cut crop and stress bushes. |
| Indian monsoon (Assam, Nilgiris) | Tends to weaken the June to September monsoon, with a mixed response in Assam. South India's northeast monsoon is often stronger. | Tends to strengthen the monsoon, raising flood risk in the Brahmaputra valley, and typically enhances the northeast monsoon over Tamil Nadu. |
| Himalayan winter (Darjeeling, Ilam) | A weak, mixed signal; local conditions at elevation dominate. | Can bring colder winters that extend into early spring, raising frost risk for first flush. |
| Sri Lanka | Mixed; October to December rains are often above normal. | Variable; can suppress inter-monsoon rainfall in the hill country. |
| Indonesia (Java) | Suppressed rainfall and a delayed wet season: dry-spell and heat stress. | Significantly more rain; lower-elevation estates face waterlogging risk. |
| Mainland South-East Asia (Vietnam, Myanmar) | Tends to be warmer and often drier, though the signal is modest. | Enhanced rainfall, generally positive for Vietnamese tea. |
| Southern Africa (Malawi) | Often a hotter, drier or delayed rainy season, a risk to the main crop. | Tends to bring more rain, though effects in southern Malawi are weaker than further north. |
| South America (north-east Argentina, southern Brazil) | Typically wetter through spring and summer, with waterlogging risk at the margins. | Tends to bring drier conditions, which can stress bushes. |
| China, Taiwan and Japan | Wetter and cooler winters in southern China and milder winters in Japan; weak direct effects on tea. | Can enhance spring rain in southern China, generally favourable for oolong and white tea; minimal effect in Japan and Taiwan's high mountains. |
| Black Sea, Caucasus and Iran | Little direct link for the Black Sea and Caucasus; Iran's winters tend to be wetter but the Caspian coast is uncertain. | Little direct link for the Caucasus; La Niña is linked to drier conditions across western and central Asia. |
Origin by origin
The typical tendency at each origin the weekly brief tracks, in each phase. These are the same notes the brief shows next to its live weather numbers.
East Africa
| Origin | In El Niño | In La Niña |
|---|---|---|
| Kericho, Kenya | El Niño typically enhances the October to December short rains across East Africa, as in 1997 to 1998, raising waterlogging, road-access and leaf-quality risks. This is a tendency, not a guarantee. | La Niña usually brings drier conditions to East Africa, which can cut crop and stress bushes. |
| Western Uganda | El Niño typically enhances October to December rains across the Great Lakes region; waterlogging and road-access risks rise. | La Niña usually brings drier conditions to East Africa. |
| Usambara, Tanzania | El Niño typically enhances the October to December vuli rains in northern and eastern Tanzania; waterlogging risk rises on lowland estates. | La Niña usually brings drier conditions to East Africa. |
| Nyungwe, Rwanda | El Niño typically enhances the short rains in Rwanda and the Great Lakes region; soil erosion and nutrient leaching are the main risks on steep slopes. | La Niña usually brings drier conditions to East Africa. |
South Asia
| Origin | In El Niño | In La Niña |
|---|---|---|
| Assam, India | El Niño years tend to weaken the June to September monsoon over India, but the response in Assam and the Brahmaputra valley is mixed and weaker than elsewhere. | La Niña tends to strengthen the Indian monsoon, which raises flood risk in the Brahmaputra valley. |
| Darjeeling, India | The El Niño signal for the eastern Himalaya is weak and mixed; local conditions at elevation dominate. | La Niña can bring colder Himalayan winters that extend into early spring, which raises frost risk for first flush. |
| Nilgiris, India | South India's October to December northeast monsoon is often stronger in El Niño years, so a wetter than normal end to the year is more likely than usual. | La Niña typically enhances the northeast monsoon over Tamil Nadu, which is generally good for high-grown estates. |
| Nuwara Eliya, Sri Lanka | Sri Lanka's response is mixed; October to December rains are often above normal in El Niño years. | La Niña effects on Sri Lanka are variable and can suppress inter-monsoon rainfall in the hill country. |
| Ilam, Nepal | El Niño's effect on eastern Nepal is weak and mixed. | La Niña is associated with colder Himalayan winters, which raises frost risk at first flush. |
| Sylhet, Bangladesh | El Niño's effect on Bangladesh's tea belt is mixed and local conditions dominate. | La Niña enhances the Indian and Bangladeshi monsoon, which raises flood risk in the Sylhet lowlands. |
China, Taiwan and Japan
| Origin | In El Niño | In La Niña |
|---|---|---|
| Yunnan, China | Southern China is often wetter and cooler in El Niño winters, but Yunnan's dry season has also run short of rain in some El Niño years. The signal is weak and local terrain dominates. | La Niña tends to bring wetter conditions to southern China, though Yunnan's complex terrain creates local dry pockets. |
| Fujian, China | El Niño winters and springs tend to be wetter and cooler across southern China, which can slow spring growth. Autumn effects are small. | La Niña can enhance spring rainfall in Fujian, which is generally favourable for oolong and white tea. |
| Alishan, Taiwan | The El Niño signal for Taiwan's high mountains is weak; local mist and temperature dominate. | Taiwan's high-mountain regions are relatively insulated from ENSO effects. |
| Uji, Japan | El Niño winters tend to be milder in Japan; the direct effect on tea is small. | La Niña has minimal impact on Japanese tea regions. |
South-East Asia
| Origin | In El Niño | In La Niña |
|---|---|---|
| Thai Nguyen, Vietnam | El Niño tends to bring warmer, often drier conditions to mainland Southeast Asia, though northern Vietnam's response is mixed. | La Niña enhances rainfall across mainland Southeast Asia, which is generally positive for Vietnamese tea. |
| West Java, Indonesia | El Niño typically suppresses rainfall over Indonesia and delays the wet season; NOAA reports convection is currently suppressed there. Dry-spell and heat stress are the main risks for estates. | La Niña brings significantly more rain to maritime Indonesia; lower-elevation estates face waterlogging risk. |
| Shan State, Myanmar | El Niño tends to tilt Myanmar's highlands towards warmer and drier conditions, though the signal is modest. | La Niña has limited direct impact on the Shan Plateau; conflict and logistics matter more than weather. |
Black Sea, Caucasus and Iran
| Origin | In El Niño | In La Niña |
|---|---|---|
| Rize, Turkey | The link between El Niño and the eastern Black Sea is weak; local weather dominates. | La Niña years can bring colder winters and later springs to the Black Sea coast. |
| Guria, Georgia | The Caucasus shows little direct El Niño link; the local Black Sea climate dominates. | The Caucasus shows little direct La Niña link; the local Black Sea climate dominates. |
| Gilan, Iran | El Niño winters tend to bring more rain to Iran, but the effect on the Caspian coast is uncertain. | La Niña is linked to drier conditions across western and central Asia. |
South America
| Origin | In El Niño | In La Niña |
|---|---|---|
| Misiones, Argentina | El Niño typically brings above-normal rain to northeast Argentina and southern Brazil through spring and summer: good for soil moisture, with waterlogging and flood risk at the margins. | La Niña tends to bring drier conditions to northeast Argentina, which can stress bushes. |
| Registro, Brazil | El Niño typically brings above-normal rain to southern Brazil through spring and summer: flood and waterlogging risk in low-lying valleys such as the Ribeira. | La Niña tends to bring drier conditions to southern Brazil, which can stress bushes. |
Southern Africa
| Origin | In El Niño | In La Niña |
|---|---|---|
| Thyolo, Malawi | El Niño often brings a hotter, drier or delayed rainy season to southern Africa (as in 2015 to 2016), a risk to the November to April main crop. | La Niña tends to bring more rain to southern Africa, though effects in southern Malawi are weaker than further north. |
Past events, briefly
The usual reference points for a strong El Niño are 1997–98 and 2015–16: East Africa saw heavy rains and flooding in late 1997, and southern Africa suffered a severe drought in 2015–16. For La Niña, forecasters described the run of three consecutive northern winters from 2020–21 to 2022–23 as a “triple-dip” La Niña.
These are weather events. How each one affected tea volumes and prices depended on far more than ENSO, and TeaTrade does not state crop or price outcomes for past events.
What it means for buyers and brands
- Ask about timing, not just volume. When an origin is on the watch list, ask suppliers about flush dates and dispatch schedules.
- Plan for logistics. Heavy rain closes roads and delays shipments to port; a dry spell tends to show up later as a lighter next flush.
- Keep a buffer on core origins while a Watch or Advisory is in force, and have a short customer note ready in case of delays.
- Treat weather as an early indicator only. This guide and the weekly brief track weather, not harvest volumes, auction prices or demand. Confirm with your suppliers before acting.
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Frequently asked questions
What is the difference between El Niño and La Niña?
El Niño is the warm phase of ENSO, with sea-surface temperatures in the Niño-3.4 region at least 0.5°C above average. La Niña is the cool phase, at least 0.5°C below. In many tea regions they push rainfall and temperature in opposite directions: East Africa's short rains are typically wetter in El Niño and drier in La Niña.
How does El Niño affect tea?
East Africa (Kenya, Uganda, Rwanda, Tanzania): El Niño typically enhances the October to December short rains, raising waterlogging, road-access and leaf-quality risks. Southern Africa (Malawi, Zimbabwe): often a hotter, drier or delayed rainy season from November; drought stress is a risk for the main crop. Indonesia (Java, Sumatra): suppressed rainfall and a delayed wet season; dry spells and heat stress are the risk. India: El Niño tends to weaken the June to September monsoon, with a mixed response in Assam and Darjeeling. South India's October to December northeast monsoon (Nilgiris) is often wetter. Sri Lanka: a mixed signal; October to December rains are often above normal. Southern Brazil and northeast Argentina: typically wetter through spring and summer, with waterlogging risk. Southern China, Taiwan and Japan: wetter and cooler winters in southern China, milder winters in Japan; weak direct effects on tea. These are typical tendencies, not forecasts, and local weather varies.
How does La Niña affect tea?
Enhanced Indian monsoon: good for Assam and the Nilgiris, but a flood risk in the Brahmaputra valley. East Africa tends to be drier, which can cut crop and stress bushes. Cooler and wetter southern China is generally favourable for spring flush. Near-normal conditions in Japan; minimal direct ENSO impact. Enhanced rainfall in maritime Southeast Asia is positive for Vietnam and Indonesia, with waterlogging risk on low estates. These are typical tendencies, not forecasts, and local weather varies.
Do El Niño and La Niña change tea prices?
ENSO changes weather, not prices directly. Prices depend on supply, demand, currency, freight and much else, and TeaTrade does not forecast them. Weather is an early indicator that can affect timing and volumes at particular origins.
Which tea origins are most exposed?
The clearest ENSO links are East Africa's October to December short rains, the Indian monsoon (Assam and the Nilgiris), Indonesia, southern Africa and southern South America. Japan, Taiwan's high mountains and the Caucasus show little direct link.
How often do El Niño and La Niña happen?
Every few years: NOAA puts the average at three to seven years, with no fixed schedule. An episode typically lasts nine to twelve months, though La Niña can last two years or more. El Niño is often, but not always, followed by La Niña the next year, particularly if the El Niño is strong.
What is the current ENSO status?
El Niño Advisory (NOAA CPC, 8 October 2026). El Niño continues to strengthen, with a strong-to-very strong El Niño likely through January-March 2027 (remaining greater than an 83% chance). The Niño-3.4 index is +2.1°C. Next NOAA update: 12 November 2026. (Status as of 8 October 2026.)
How can I follow El Niño and La Niña and tea weather each week?
The TeaTrade Tea Weather Brief is updated every Sunday afternoon with the latest NOAA ENSO status and the last 30 days of rain and temperature against average for the world's main tea origins. You can get it by free email from the sign-up box on this page.
Sources and how this page is kept current
Sources, method and limits
The "right now" tiles and paragraph are refreshed every Sunday from NOAA's latest ENSO Diagnostic Discussion by the same process that writes the Tea Weather Brief. Everything else on this page is written to be true in every phase. The origin notes are TeaTrade's editorial summary of published regional ENSO tendencies: they are tendencies, not forecasts, and they are not forecasts of crop size or price.
Sources
- NOAA Climate Prediction Center: ENSO Diagnostic Discussion
- NOAA Climate Prediction Center: ENSO Alert System
- NOAA Climate Prediction Center: Relative Oceanic Niño Index (RONI)
- NOAA Climate.gov: El Niño and La Niña frequently asked questions
Editorial analysis for information only: not financial or trading advice.