This week in brief
- ENSO: El Niño (very strong, strengthening). NOAA status: El Niño Advisory. The Oceanic Niño Index is +2.2°C (JAS 2026) and the relative index is +1.7°C (JAS 2026).
- Overview: 18 of 23 monitored origins show an elevated or high signal this week: 7 high, 11 elevated (including 2 El Niño watches).
- Wettest versus normal: Nuwara Eliya (+216%), Darjeeling (+131%) and Rize (+130%) over the last 30 days.
- Driest versus normal: West Java (−88%), Gilan (−69%) and Alishan (−63%) over the last 30 days.
- Week ahead: Wetter than a normal week is forecast for Nyungwe (about 107 mm against 18 mm), Nilgiris (about 122 mm against 33 mm) and Nuwara Eliya (about 111 mm against 39 mm).
- Warmest versus normal: Nyungwe (+3.1°C), Nilgiris (+2.2°C) and Western Uganda (+2.0°C).
- El Niño watch: Typical El Niño tendencies point to wetter than usual for Usambara and Registro. These are typical tendencies, not forecasts of crop loss.
El Niño and the tea trade
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.
Oceanic Niño Index, recent seasons
Red line: ONI. Dashed blue: relative ONI (RONI). Above +0.5°C is El Niño territory, below −0.5°C is La Niña.
Typical El Niño tendencies by tea origin
- 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. Local weather varies and NOAA notes impacts are more likely in a strong event, though not guaranteed.
Source: NOAA Climate Prediction Center ENSO Diagnostic Discussion and ONI/RONI tables, as of 8 October 2026. ONI is the three-month average Niño-3.4 sea-surface temperature anomaly; RONI is the same measure relative to the tropical-wide average.
Origins to watch this week
Darjeeling
Heavy rain: 131% above average
Rain 359 mm (+131%) · temp 18.5°C (+0.6) · next 7 days 8 mm
Nilgiris
Heavy rain: 76% above average
Rain 175 mm (+76%) · temp 23.6°C (+2.2) · next 7 days 122 mm
Nuwara Eliya
Heavy rain: 216% above average
Rain 404 mm (+216%) · temp 23.4°C (+1.0) · next 7 days 111 mm
Rize
Heavy rain: 130% above average
Rain 250 mm (+130%) · temp 13.1°C (+0.7) · next 7 days 25 mm
West Java
Dry spell: rainfall 88% below average
Rain 13 mm (−88%) · temp 26.8°C (+1.3) · next 7 days 2 mm
Gilan
Dry spell: rainfall 69% below average
Rain 48 mm (−69%) · temp 23°C (+1.8) · next 7 days 7 mm
Nyungwe
Running 3.1°C warmer than average
Rain 32 mm (−55%) · temp 22.1°C (+3.1) · next 7 days 107 mm
Kericho
Heavy rain: 35% above average
Rain 140 mm (+35%) · temp 21.6°C (+1.6) · next 7 days 81 mm
Rain, temperature and the week ahead
Rainfall against average
Last 30 days, % above or below the 1991 to 2020 average. Bars cap at ±200%; labels are exact.
Heavy rainWetNormalDryVery dry
Temperature against average
Average temperature over the last 30 days, °C above or below the 1991 to 2020 average.
HotWarmNormalCoolCold
Rain forecast, next 7 days
Forecast total (blue) against a normal week (grey), in millimetres, for the 12 wettest forecasts. Every origin is in the tables below. Source: MET Norway.
Much wetter than normalForecastNormal week
Origin by origin
Rain and temperature are for the last 30 days to 12 October 2026, against the 1991 to 2020 average for the same dates. The last column is the forecast total for the next seven days against a normal week.
East Africa
4 of 4 origins flagged this week (2 heat, 1 heavy rain, 1 El Niño watch).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Nyungwe, Rwanda | High · Heat | 32 mm (−55%) | 22.1°C (+3.1) | 107 mm (normal 18) |
| Kericho, Kenya | Elevated · Heavy rain | 140 mm (+35%) | 21.6°C (+1.6) | 81 mm (normal 36) |
| Western Uganda | Elevated · Heat | 50 mm (−24%) | 24.2°C (+2.0) | 46 mm (normal 22) |
| Usambara, Tanzania | El Niño watch | 66 mm (+83%) | 22.1°C (+0.8) | 12 mm (normal 13) |
Detail and El Niño context for East Africa
Nyungwe, Rwanda: Running 3.1°C warmer than average
In the 30 days to 12 Oct, Nyungwe recorded 32 mm of rain (-55% below avg; the 1991 to 2020 norm for the period is 72 mm) and averaged 22.1°C (+3.1°C vs average). The short rains season is under way.
Week ahead: about 107 mm of rain forecast (a normal week brings about 18 mm), wetter than normal, averaging 14.8°C.
ENSO context: 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.
Kericho, Kenya: Heavy rain: 35% above average
In the 30 days to 12 Oct, Kericho recorded 140 mm of rain (+35% above avg; the 1991 to 2020 norm for the period is 103 mm) and averaged 21.6°C (+1.6°C vs average). Kenya picks all year; the short rains (October to December) usually lift the crop.
Week ahead: about 81 mm of rain forecast (a normal week brings about 36 mm), wetter than normal, averaging 16.5°C.
ENSO context: 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.
Western Uganda: Running 2°C warmer than average
In the 30 days to 12 Oct, Western Uganda recorded 50 mm of rain (-24% below avg; the 1991 to 2020 norm for the period is 65 mm) and averaged 24.2°C (+2.0°C vs average). Production runs all year; the short rains lift crop but can hurt access and leaf quality.
Week ahead: about 46 mm of rain forecast (a normal week brings about 22 mm), wetter than normal, averaging 19.6°C.
ENSO context: El Niño typically enhances October to December rains across the Great Lakes region; waterlogging and road-access risks rise.
Usambara, Tanzania: El Niño watch: heavy vuli rains likely
El Niño tilts the odds towards above-normal October to December rains in north-east Tanzania: watch for waterlogging on lowland estates and washed-out roads. In the 30 days to 12 Oct, Usambara recorded 66 mm of rain (+83% above avg; the 1991 to 2020 norm for the period is 36 mm) and averaged 22.1°C (+0.8°C vs average). The short (vuli) rains are due; they lift crop but can flood lowland estates.
Week ahead: about 12 mm of rain forecast (a normal week brings about 13 mm), averaging 23.9°C.
ENSO context: El Niño typically enhances the October to December vuli rains in northern and eastern Tanzania; waterlogging risk rises on lowland estates.
South Asia
5 of 6 origins flagged this week (3 heavy rain, 2 dry spell).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Darjeeling, India | High · Heavy rain | 359 mm (+131%) | 18.5°C (+0.6) | 8 mm (normal 16) |
| Nilgiris, India | High · Heavy rain | 175 mm (+76%) | 23.6°C (+2.2) | 122 mm (normal 33) |
| Nuwara Eliya, Sri Lanka | High · Heavy rain | 404 mm (+216%) | 23.4°C (+1.0) | 111 mm (normal 39) |
| Assam, India | Elevated · Dry spell | 77 mm (−58%) | 27.9°C (+0.5) | 5 mm (normal 23) |
| Sylhet, Bangladesh | Elevated · Dry spell | 198 mm (−40%) | 29.5°C (+1.0) | 0 mm (normal 68) |
| Ilam, Nepal | Low | 171 mm (+28%) | 26°C (+0.6) | 3 mm (normal 16) |
Detail and El Niño context for South Asia
Darjeeling, India: Heavy rain: 131% above average
In the 30 days to 12 Oct, Darjeeling recorded 359 mm of rain (+131% above avg; the 1991 to 2020 norm for the period is 155 mm) and averaged 18.5°C (+0.6°C vs average). Autumn flush picking runs through October into early November.
Week ahead: about 8 mm of rain forecast (a normal week brings about 16 mm), averaging 12.9°C.
ENSO context: The El Niño signal for the eastern Himalaya is weak and mixed; local conditions at elevation dominate.
Nilgiris, India: Heavy rain: 76% above average
In the 30 days to 12 Oct, Nilgiris recorded 175 mm of rain (+76% above avg; the 1991 to 2020 norm for the period is 100 mm) and averaged 23.6°C (+2.2°C vs average). The northeast monsoon rains (October to December) shape the crop.
Week ahead: about 122 mm of rain forecast (a normal week brings about 33 mm), wetter than normal, averaging 15.6°C.
ENSO context: 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.
Nuwara Eliya, Sri Lanka: Heavy rain: 216% above average
In the 30 days to 12 Oct, Nuwara Eliya recorded 404 mm of rain (+216% above avg; the 1991 to 2020 norm for the period is 128 mm) and averaged 23.4°C (+1.0°C vs average). Inter-monsoon and northeast monsoon rains shape crop and quality.
Week ahead: about 111 mm of rain forecast (a normal week brings about 39 mm), wetter than normal, averaging 16.2°C.
ENSO context: Sri Lanka's response is mixed; October to December rains are often above normal in El Niño years.
Assam, India: Dry spell: rainfall 58% below average
In the 30 days to 12 Oct, Assam recorded 77 mm of rain (-58% below avg; the 1991 to 2020 norm for the period is 182 mm) and averaged 27.9°C (+0.5°C vs average). The autumn flush is winding down before winter dormancy.
Week ahead: about 5 mm of rain forecast (a normal week brings about 23 mm), drier than normal, averaging 25°C.
ENSO context: 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.
Sylhet, Bangladesh: Dry spell: rainfall 40% below average
In the 30 days to 12 Oct, Sylhet recorded 198 mm of rain (-40% below avg; the 1991 to 2020 norm for the period is 332 mm) and averaged 29.5°C (+1.0°C vs average). The season is closing out; growth slows from late November.
Week ahead: about 0 mm of rain forecast (a normal week brings about 68 mm), drier than normal, averaging 26.2°C.
ENSO context: El Niño's effect on Bangladesh's tea belt is mixed and local conditions dominate.
Ilam, Nepal: Somewhat wetter than usual
In the 30 days to 12 Oct, Ilam recorded 171 mm of rain (+28% above avg; the 1991 to 2020 norm for the period is 134 mm) and averaged 26°C (+0.6°C vs average). Autumn flush picking is finishing before winter dormancy.
Week ahead: about 3 mm of rain forecast (a normal week brings about 16 mm), drier than normal, averaging 18.7°C.
ENSO context: El Niño's effect on eastern Nepal is weak and mixed.
China, Taiwan and Japan
2 of 4 origins flagged this week (2 dry spell).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Yunnan, China | Elevated · Dry spell | 35 mm (−59%) | 20.5°C (+0.9) | 1 mm (normal 9) |
| Alishan, Taiwan | Elevated · Dry spell | 47 mm (−63%) | 26.1°C (+1.9) | 10 mm (normal 5) |
| Fujian, China | Low | 63 mm (+17%) | 25.6°C (+1.4) | 0 mm (normal 5) |
| Uji, Japan | Low | 140 mm (−13%) | 23.6°C (+1.3) | 7 mm (normal 34) |
Detail and El Niño context for China, Taiwan and Japan
Yunnan, China: Dry spell: rainfall 59% below average
In the 30 days to 12 Oct, Yunnan recorded 35 mm of rain (-59% below avg; the 1991 to 2020 norm for the period is 85 mm) and averaged 20.5°C (+0.9°C vs average). Autumn pu-erh picking is winding down.
Week ahead: about 1 mm of rain forecast (a normal week brings about 9 mm), averaging 16.2°C.
ENSO context: 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.
Alishan, Taiwan: Dry spell: rainfall 63% below average
In the 30 days to 12 Oct, Alishan recorded 47 mm of rain (-63% below avg; the 1991 to 2020 norm for the period is 129 mm) and averaged 26.1°C (+1.9°C vs average). Autumn and winter high-mountain oolong picking.
Week ahead: about 10 mm of rain forecast (a normal week brings about 5 mm), averaging 17.6°C.
ENSO context: The El Niño signal for Taiwan's high mountains is weak; local mist and temperature dominate.
Fujian, China: Slightly warmer than usual
In the 30 days to 12 Oct, Fujian recorded 63 mm of rain (+17% above avg; the 1991 to 2020 norm for the period is 53 mm) and averaged 25.6°C (+1.4°C vs average). Autumn oolong picking typically runs through October.
Week ahead: about 0 mm of rain forecast (a normal week brings about 5 mm), averaging 23.6°C.
ENSO context: El Niño winters and springs tend to be wetter and cooler across southern China, which can slow spring growth. Autumn effects are small.
Uji, Japan: Slightly warmer than usual
In the 30 days to 12 Oct, Uji recorded 140 mm of rain (-13% below avg; the 1991 to 2020 norm for the period is 162 mm) and averaged 23.6°C (+1.3°C vs average). The main spring harvest is months away; autumn weather matters mostly for bush health.
Week ahead: about 7 mm of rain forecast (a normal week brings about 34 mm), drier than normal, averaging 20.4°C.
ENSO context: El Niño winters tend to be milder in Japan; the direct effect on tea is small.
South-East Asia
2 of 3 origins flagged this week (1 dry spell, 1 heavy rain).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| West Java, Indonesia | High · Dry spell | 13 mm (−88%) | 26.8°C (+1.3) | 2 mm (normal 42) |
| Shan State, Myanmar | Elevated · Heavy rain | 92 mm (+55%) | 21.5°C (−0.6) | 23 mm (normal 12) |
| Thai Nguyen, Vietnam | Low | 138 mm (+5%) | 28°C (+0.6) | 17 mm (normal 25) |
Detail and El Niño context for South-East Asia
West Java, Indonesia: Dry spell: rainfall 88% below average
In the 30 days to 12 Oct, West Java recorded 13 mm of rain (-88% below avg; the 1991 to 2020 norm for the period is 107 mm) and averaged 26.8°C (+1.3°C vs average). The dry season normally gives way to the wet season around now.
Week ahead: about 2 mm of rain forecast (a normal week brings about 42 mm), drier than normal, averaging 25.1°C.
ENSO context: 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.
Shan State, Myanmar: Heavy rain: 55% above average
In the 30 days to 12 Oct, Shan State recorded 92 mm of rain (+55% above avg; the 1991 to 2020 norm for the period is 59 mm) and averaged 21.5°C (-0.6°C vs average).
Week ahead: about 23 mm of rain forecast (a normal week brings about 12 mm), averaging 19.2°C.
ENSO context: El Niño tends to tilt Myanmar's highlands towards warmer and drier conditions, though the signal is modest.
Thai Nguyen, Vietnam: Conditions close to normal
In the 30 days to 12 Oct, Thai Nguyen recorded 138 mm of rain (+5% above avg; the 1991 to 2020 norm for the period is 131 mm) and averaged 28°C (+0.6°C vs average). The main harvest is tailing off ahead of winter dormancy.
Week ahead: about 17 mm of rain forecast (a normal week brings about 25 mm), averaging 27.1°C.
ENSO context: El Niño tends to bring warmer, often drier conditions to mainland Southeast Asia, though northern Vietnam's response is mixed.
Black Sea, Caucasus and Iran
2 of 3 origins flagged this week (1 heavy rain, 1 dry spell).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Rize, Turkey | High · Heavy rain | 250 mm (+130%) | 13.1°C (+0.7) | 25 mm (normal 33) |
| Gilan, Iran | High · Dry spell | 48 mm (−69%) | 23°C (+1.8) | 7 mm (normal 40) |
| Guria, Georgia | Low | 128 mm (+14%) | 14.8°C (+0.5) | 6 mm (normal 43) |
Detail and El Niño context for Black Sea, Caucasus and Iran
Rize, Turkey: Heavy rain: 130% above average
In the 30 days to 12 Oct, Rize recorded 250 mm of rain (+130% above avg; the 1991 to 2020 norm for the period is 109 mm) and averaged 13.1°C (+0.7°C vs average). The harvest season has ended and bushes are going dormant.
Week ahead: about 25 mm of rain forecast (a normal week brings about 33 mm), averaging 9.8°C.
ENSO context: The link between El Niño and the eastern Black Sea is weak; local weather dominates.
Gilan, Iran: Dry spell: rainfall 69% below average
In the 30 days to 12 Oct, Gilan recorded 48 mm of rain (-69% below avg; the 1991 to 2020 norm for the period is 153 mm) and averaged 23°C (+1.8°C vs average). Harvest is over; autumn and winter rain matters for the next season.
Week ahead: about 7 mm of rain forecast (a normal week brings about 40 mm), drier than normal, averaging 22.6°C.
ENSO context: El Niño winters tend to bring more rain to Iran, but the effect on the Caspian coast is uncertain.
Guria, Georgia: Conditions close to normal
In the 30 days to 12 Oct, Guria recorded 128 mm of rain (+14% above avg; the 1991 to 2020 norm for the period is 112 mm) and averaged 14.8°C (+0.5°C vs average). The harvest is over and bushes are going dormant.
Week ahead: about 6 mm of rain forecast (a normal week brings about 43 mm), drier than normal, averaging 18.5°C.
ENSO context: The Caucasus shows little direct El Niño link; the local Black Sea climate dominates.
South America
2 of 2 origins flagged this week (1 heavy rain, 1 El Niño watch).
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Misiones, Argentina | Elevated · Heavy rain | 316 mm (+53%) | 21.8°C (+1.1) | 41 mm (normal 60) |
| Registro, Brazil | El Niño watch | 139 mm (−11%) | 20.6°C (−0.1) | 65 mm (normal 37) |
Detail and El Niño context for South America
Misiones, Argentina: Heavy rain: 53% above average
In the 30 days to 12 Oct, Misiones recorded 316 mm of rain (+53% above avg; the 1991 to 2020 norm for the period is 207 mm) and averaged 21.8°C (+1.1°C vs average). The main harvest season is open (October to April).
Week ahead: about 41 mm of rain forecast (a normal week brings about 60 mm), averaging 18.5°C.
ENSO context: 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.
Registro, Brazil: El Niño watch: wetter spring and summer likely
El Niño tilts the odds towards above-normal rain across southern Brazil this season: watch for waterlogging in the Ribeira valley. In the 30 days to 12 Oct, Registro recorded 139 mm of rain (-11% below avg; the 1991 to 2020 norm for the period is 156 mm) and averaged 20.6°C (-0.1°C vs average). The warm-season harvest is under way.
Week ahead: about 65 mm of rain forecast (a normal week brings about 37 mm), wetter than normal, averaging 20.5°C.
ENSO context: 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.
Southern Africa
Flagged this week: heavy rain.
| Origin | Signal | Rain, last 30 days (vs average) | Temperature (vs average) | Next 7 days: rain |
|---|---|---|---|---|
| Thyolo, Malawi | Elevated · Heavy rain | 101 mm (+92 mm) | 24.2°C (+0.4) | 1 mm (normal 1) |
Detail and El Niño context for Southern Africa
Thyolo, Malawi: Unseasonably wet: 101 mm against 8 mm normal
In the 30 days to 12 Oct, Thyolo recorded 101 mm of rain (+92 mm vs avg; the 1991 to 2020 norm for the period is 8 mm) and averaged 24.2°C (+0.4°C vs average). The dry season ends; the November to April rains drive the main crop.
Week ahead: about 1 mm of rain forecast (a normal week brings about 1 mm), averaging 24.9°C.
ENSO context: 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.
What it means for buyers and brands
- Heavy-rain origins (Darjeeling, Nilgiris, Nuwara Eliya, Rize, Kericho, Shan State, Misiones and Thyolo). After sustained heavy rain, waterlogging and washed-out estate roads can slow plucking and dispatch, and leaf quality can be diluted. If you have shipments due from these origins, it is reasonable to ask suppliers about logistics and expected dates.
- Dry-spell origins (West Java, Gilan, Yunnan, Assam, Sylhet and Alishan). A prolonged dry spell can stress bushes and reduce yield in the following flush. Ask about the crop outlook for the next picking rather than assuming volumes.
- Warm origins (Nyungwe and Western Uganda). Unusually warm weather can speed growth and affect leaf quality. Timing of the next flush is the thing to ask about.
- El Niño is in force. Past strong events have shifted rainfall patterns across several tea origins within a few months, and Usambara and Registro are on the watch list this week. Treat these as risks to monitor, not as forecasts of crop loss; local weather varies.
- Brands and retailers. If a core origin is flagged, it is worth checking buffer stock and supplier lead times, and having a short customer note ready in case of delays.
- What this brief does not cover. It tracks weather, not harvest volumes, auction prices or demand. Weather signals are early indicators at best; confirm with your suppliers before acting.
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Frequently asked questions
What is the current ENSO status for tea growers?
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. (Updated 14 October 2026.)
How does El Niño affect tea?
El Niño shifts rainfall and temperature patterns, and the effect differs by origin. Typical tendencies in El Niño years: 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. These are tendencies, not forecasts, and local weather varies.
How often is the Tea Weather Brief updated?
Every Sunday afternoon (UK time), on this page. Each update compares the last 30 days of observed rain and temperature with the 1991 to 2020 average for each origin, adds the next seven days of forecast, and reports the latest NOAA El Niño status.
Where does the data come from?
Observed rain and temperature come from NOAA Climate Prediction Center gauge-based daily analyses (via NOAA PSL). The week-ahead forecast is from MET Norway, and El Niño status is from the NOAA Climate Prediction Center. The figures are indicative and smooth mountain terrain.
Which tea origins are covered?
Twenty-three tea-growing districts across East Africa, South Asia, China, Taiwan, Japan, South-East Asia, the Black Sea and Caucasus, Iran, South America and Southern Africa. Weather is measured for a point in each district, not for individual estates.
How this brief is made
Method, thresholds, sources and limits
Each Sunday, TeaTrade compiles public weather data for 23 tea-growing districts, compares it with the long-run average for the same dates, and applies fixed thresholds so the same numbers always give the same signal. The wording is generated from those numbers, with El Niño notes drawn from published research on typical regional impacts. It is not a forecast of crop size or price.
- Heavy rain: rainfall over the last 30 days at least 35% above the 1991 to 2020 average and at least 80 mm (high: 75% above and at least 150 mm). In normally dry periods, where percentages mislead, the test is millimetres above average: 60 mm (high: 120 mm).
- Dry spell: rainfall at least 35% below average (high: 65% below, where the normal total is at least 60 mm).
- Heat: average temperature at least 1.5°C above normal (high: 2.5°C). Cold: at least 2°C below normal (high: 3.5°C).
- Forecast: at least 100 mm expected in the next seven days and at least 1.8 times a normal week raises a heavy-rain flag.
- El Niño watch: shown only while NOAA has an El Niño Advisory in force and the origin is in the part of its season that El Niño typically affects. It is a risk flag from typical El Niño tendencies, not observed weather.
Sources
- Observed rain and temperature: NOAA Climate Prediction Center gauge-based daily analyses, provided by NOAA PSL (psl.noaa.gov). Baseline: 1991 to 2020.
- Week-ahead forecast: MET Norway Locationforecast (api.met.no), licensed CC BY 4.0.
- El Niño status, ONI and RONI: NOAA Climate Prediction Center, ENSO Diagnostic Discussion.
TeaTrade compiles weather figures from the public sources above; they are model-based and indicative, and reanalysis smooths mountain terrain. ENSO impacts are typical tendencies, not forecasts. Editorial analysis for information only: not financial or trading advice. Weather is measured for a point in each district, not for individual estates.