El Niño 2026–27 in Japan
Odds favour a wetter-than-normal December–February in Japan (80% chance). Past El Niño years show no consistent rainfall pattern here.
Temperatures: likely warmer than the 1993–2016 average (96% chance).
El Niño status: El Niño Advisory (NOAA, 12 November 2026). Outlook: Copernicus, issued November 2026.
Outlook for the next six months
December–February
Rainfall: likely wetter
Temperature: likely warmer
February–April
Rainfall: likely wetter
Temperature: likely warmer
Away from the tropics, seasonal rainfall forecasts have limited skill. Treat small shifts in the odds as weak signals. “Normal” means the middle third of the model's own 1993–2016 range; because the climate has warmed since then, “warmer” is the usual result almost everywhere.
Source: Copernicus Climate Change Service seasonal forecast (Copernicus Climate Change Service (C3S) seasonal forecasts, ECMWF system 51), country average. How this is calculated.
Air quality, next 4 days
Worst forecast day: Tokyo, 15 November 2026: Unhealthy for Sensitive Groups (PM2.5 45.1 µg/m³, AQI 125).
| City | 11/15 | 11/16 | 11/17 | 11/18 |
|---|---|---|---|---|
| Tokyo (capital) | 125Unhealthy for Sensitive Groups | 76Moderate | 66Moderate | 124Unhealthy for Sensitive Groups |
| Kyoto (capital) | 45Good | 55Moderate | 34Good | 31Good |
| Ōsaka | 66Moderate | 69Moderate | 59Moderate | 54Moderate |
| Yokohama | 125Unhealthy for Sensitive Groups | 76Moderate | 66Moderate | 124Unhealthy for Sensitive Groups |
| Nagoya | 60Moderate | 62Moderate | 65Moderate | 50Good |
AQI = US EPA 24-hour PM2.5 scale (2024). Model forecast for an area of about 40 km, not a local measurement. Local levels can be higher or lower. Dates are UTC days.
Source: Copernicus Atmosphere Monitoring Service global forecast, run 2026-11-14 00 UTC.
What happened in past El Niños
Each row compares El Niño seasons with all other years in 1979-2025, after removing the long-term trend.
| Season | Rainfall | Temperature |
|---|---|---|
| Dec–Feb | No consistent pattern (about 3% more rain on average) | Warmer in 11 of 15 El Niño seasons (+0.7 °C on average) |
| Jan–Mar | No consistent pattern (about 7% more rain on average) | Warmer in 10 of 13 El Niño seasons (+0.3 °C on average) |
| Feb–Apr | Wetter in 8 of 10 El Niño seasons (about 11% more rain on average) | Warmer in 8 of 10 El Niño seasons (+0.5 °C on average) |
| Mar–May | No consistent pattern (about 6% more rain on average) | Warmer in 7 of 8 El Niño seasons (+0.7 °C on average) |
| Apr–Jun | No consistent pattern (about 4% less rain on average) | No consistent pattern (+0.2 °C on average) |
| May–Jul | No consistent pattern (about 2% more rain on average) | No consistent pattern (+0.0 °C on average) |
| Jun–Aug | Wetter in 6 of 8 El Niño seasons (about 5% more rain on average) | No consistent pattern (−0.1 °C on average) |
| Jul–Sep | No consistent pattern (about 2% more rain on average) | No consistent pattern (−0.2 °C on average) |
| Aug–Oct | No consistent pattern (about 6% less rain on average) | Cooler in 9 of 12 El Niño seasons (−0.3 °C on average) |
| Sep–Nov | No consistent pattern (about 4% less rain on average) | No consistent pattern (−0.0 °C on average) |
| Oct–Dec | No consistent pattern (about 2% more rain on average) | Warmer in 11 of 15 El Niño seasons (+0.3 °C on average) |
| Nov–Jan | No consistent pattern (about 4% more rain on average) | Warmer in 12 of 15 El Niño seasons (+0.6 °C on average) |
Source: ERA5 monthly reanalysis (Copernicus Climate Change Service); El Niño seasons from NOAA's Oceanic Niño Index. Method.
Official warnings
Japan Meteorological Agency (JMA)
This is not an official forecast or warning. Seasonal outlooks give odds, not certainties. For warnings and decisions about safety, follow your national weather service.
What you can do
If it turns out wetter
- Find out whether your home, school or workplace is in a flood-risk area, and know your evacuation route.
- Clear gutters and drains before the rainy months.
- Keep important documents, medicines and a torch in a waterproof bag.
- After heavy rain, avoid walking or driving through flood water and follow local advice on drinking water and mosquito-borne disease.
If it turns out hotter
- Check on older relatives, neighbours and anyone who lives alone during hot spells.
- Drink water regularly, and avoid hard outdoor work in the hottest hours.
- Know the signs of heat exhaustion (dizziness, headache, nausea) and when to get medical help.
On smoky or hazy days
- Check the daily air-quality forecast and cut down hard outdoor exercise when it is 'Unhealthy' or worse.
- A well-fitted N95 or KN95 mask reduces smoke exposure; cloth and surgical masks do much less.
- Keep windows closed and use an air purifier with a HEPA filter if you have one.
- People with asthma, heart or lung disease, older people, children and pregnant people should take extra care.
Get a free alert when this changes
Country alerts start in December 2026. Check back here, or see the status page for the next official update dates.
Nearby countries
China · Dem. Rep. Korea · Hong Kong · Macao · Mongolia · Republic of Korea · Taiwan
Sources and dates
- El Niño status: NOAA Climate Prediction Center, 12 November 2026.
- Seasonal outlook: Copernicus Climate Change Service, Copernicus Climate Change Service (C3S) seasonal forecasts, ECMWF system 51, issued November 2026.
- Air quality: Copernicus Atmosphere Monitoring Service, run 2026-11-14 00 UTC.
- Past El Niños: ERA5 (Copernicus Climate Change Service), 1979-2025; NOAA Oceanic Niño Index.
Cite this page: “El Niño 2026–27 in Japan”, El Niño Atlas, https://elninoatlas.pages.dev/country/japan/, updated 15 November 2026.
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