Japan weather agency says El Niño reached record strength in September
In short
The Japan Meteorological Agency said on October 9 that the El Niño event under way since spring became the strongest on record in September, with sea surface temperatures in its monitoring area 4.0 degrees above the reference value. That beats the previous high of plus 3.6 degrees in December 1997. The agency expects El Niño to continue into winter, and Japanese outlets reported a warm winter is likely in Japan.
Read the full story 2 min read
The Japan Meteorological Agency (JMA) said on October 9 that the El Niño event that has continued since spring became the strongest on record in September. Sea surface temperature in the El Niño monitoring area in September was 4.0 degrees above the reference value, surpassing the previous high of plus 3.6 degrees set in December 1997, the agency said. [ 1 , 6 , 7 , 10 ]
According to Jiji Press, the reference value is the average over 30 years, and the September gap was the largest since 1949 for any month of the year. NHK said the difference was the largest since records began. The monitoring area lies off Peru in South America, NHK and Livedoor News reported. [ 7 , 10 , 13 ]
In its latest El Niño monitoring report, the JMA put the probability of El Niño continuing into winter at 100%, TBS NEWS DIG reported. Jiji Press said the event is expected to peak around December and to continue at least until February next year, and a TBS NEWS DIG headline said it is expected to strengthen further toward winter. [ 2 , 6 , 7 , 9 ]
Until February, the influence of cold air near Japan is expected to be small, Jiji Press reported. Average temperatures are forecast to be above normal in eastern and western Japan and Okinawa-Amami, and normal or above normal in northern Japan (Hokkaido and Tohoku). Masayuki Tsuneda (経田正幸), head of the JMA's extreme weather information centre, said: "Looking at past El Niño events, Japan's winters tend to be warm." TBS NEWS DIG reported that Japan is expected to have a warm winter. [ 7 , 11 , 13 ]
El Niño is a condition in which sea surface temperatures in the central to eastern equatorial Pacific stay high, and it can be a factor in abnormal weather around the world, Nippon TV News reported. Livedoor News said it may have been a factor in the many typhoons that formed around Japan this summer. TBS NEWS DIG noted that during a past El Niño, central Tokyo saw 15 cm of snow. [ 1 , 2 , 6 , 13 ]
Why it matters
El Niño can be a factor behind abnormal weather around the world, according to the outlets. The agency's outlook points to above-normal winter temperatures in much of Japan through February, and one outlet noted El Niño may have contributed to the many typhoons near Japan this summer.
Key facts
- The Japan Meteorological Agency (JMA) announced on October 9 that El Niño reached its strongest level on record in September. [ 1 , 6 , 7 , 10 ]
- Sea surface temperature in the El Niño monitoring area in September was 4.0 degrees above the reference value. [ 1 , 6 , 7 , 10 ]
- The previous record was plus 3.6 degrees in December 1997. [ 1 , 6 , 7 ]
- The El Niño event has continued since spring 2026. [ 1 , 6 , 9 ]
- The JMA put the chance of El Niño continuing into winter at 100%. [ 2 , 6 ]
- Jiji Press reported the event is expected to peak around December and last at least until February next year. [ 7 ]
- Average temperatures are forecast to be above normal in eastern and western Japan and Okinawa-Amami, and normal or above normal in northern Japan. [ 7 , 13 ]
Confirmed by several sources
- The JMA said El Niño reached record strength in September. [ 1 , 6 , 7 , 10 , 13 ]
- September sea surface temperature in the monitoring area was 4.0 degrees above the reference value. [ 1 , 6 , 7 , 10 ]
- The figure exceeds the previous high of plus 3.6 degrees recorded in December 1997. [ 1 , 6 , 7 ]
- The JMA expects El Niño to continue into winter. [ 1 , 2 , 6 , 7 , 13 ]
- Temperatures are forecast to be above normal in eastern and western Japan and Okinawa-Amami, and normal or above in northern Japan. [ 7 , 13 ]
Still unclear
- Whether El Niño will peak around December. Only Jiji Press reported a December peak.
- Whether El Niño caused the many typhoons near Japan this summer. Only Livedoor News raised this, and only as a possible factor.
- When central Tokyo saw 15 cm of snow during a past El Niño. TBS NEWS DIG mentioned the snowfall in headlines without giving details.
What local media are saying
Timeline, local time
- Nippon TV News reports the JMA announcement that El Niño reached record strength in September. [ 1 ]
- TBS NEWS DIG reports the JMA puts the chance of El Niño continuing into winter at 100%. [ 2 ]
- Jiji Press reports El Niño is expected to peak around December and last until at least February. [ 7 ]
- NHK reports the 4.0-degree anomaly as the largest since records began. [ 10 ]
- Livedoor News carries a JMA official's comment that Japanese winters tend to be warm during El Niño. [ 13 ]