El Niño 1977-1978
El Niño 1977-1978 lasted about 7 months, from Sep–Nov 1977 to Jan–Mar 1978. The Oceanic Niño Index peaked at +0.8 °C in OND 1977, a weak El Niño, ranked #20 of 23 since 1950.
StartSON 1977Sep–Nov
EndJFM 1978Jan–Mar
Duration7 months5 seasons
Peak ONI+0.8 °COND 1977
Average ONI+0.71 °Cduring the episode
StrengthWeak#20 / 23
ONI before, during and after El Niño 1977-1978
Season by season
| Season | Year | ONI | Niño 3.4 temp. |
|---|---|---|---|
| SON Sep–Nov | 1977 | +0.7 °C | 27.17 °C |
| OND Oct–Dec | 1977 | +0.8 °C | 27.31 °C |
| NDJ Nov–Jan | 1977 | +0.8 °C | 27.25 °C |
| DJF Dec–Feb | 1978 | +0.7 °C | 27.18 °C |
| JFM Jan–Mar | 1978 | +0.5 °C | 27.19 °C |
Compare with other episodes
← El Niño 1976-1977El Niño 1982-1983 →El Niño 2026 (current)
Frequently asked questions
When did El Niño 1977-1978 start and end?
It started in SON 1977 and ended in JFM 1978, about 7 months.
How strong was El Niño 1977-1978?
Its peak ONI was +0.8 °C (OND 1977), classified as weak. It ranks #20 among 23 El Niño episodes since 1950.
How does it compare with the current El Niño?
The current event (El Niño 2026) has reached +2.5 °C so far, above the +0.8 °C peak of El Niño 1977-1978.
Episodes are computed from NOAA's Oceanic Niño Index (ERSSTv5) with the standard rule: five or more consecutive overlapping seasons at or beyond ±0.5 °C. Free to cite with a link to elninoforecast.com.