ONI & RONI Historical Index, 1950-Present
The Oceanic Nino Index (ONI) and Relative Oceanic Nino Index (RONI) for every overlapping 3-month season on record, updated automatically from NOAA CPC's published tables. RONI is NOAA's operational classification index since February 2026; ONI is shown alongside for historical continuity. See why the two differ and our classification methodology.
| Season | ONI (°C) | RONI (°C) | Classification |
|---|---|---|---|
| MJJ 2026 | +1.20 | +0.65 | El Nino (moderate) |
| AMJ 2026 | +0.94 | +0.39 | El Nino (weak) |
| MAM 2026 | +0.70 | +0.15 | El Nino (weak) |
| FMA 2026 | +0.48 | -0.07 | Neutral |
| JFM 2026 | +0.30 | -0.25 | Neutral |
| DJF 2026 | +0.30 | -0.25 | Neutral |
| NDJ 2025 | +0.30 | -0.24 | Neutral |
| OND 2025 | +0.30 | -0.24 | Neutral |
| SON 2025 | +0.30 | -0.24 | Neutral |
| ASO 2025 | +0.20 | -0.34 | Neutral |
| JAS 2025 | +0.20 | -0.34 | Neutral |
| JJA 2025 | +0.20 | -0.34 | Neutral |
| MJJ 2025 | +0.20 | -0.34 | Neutral |
| AMJ 2025 | +0.20 | -0.34 | Neutral |
| MAM 2025 | +0.10 | -0.44 | Neutral |
| FMA 2025 | -0.10 | -0.64 | Neutral |
| JFM 2025 | -0.30 | -0.84 | Neutral |
| DJF 2025 | -0.50 | -1.04 | La Nina (weak) |
| NDJ 2024 | -0.60 | -1.14 | La Nina (weak) |
| OND 2024 | -0.60 | -1.14 | La Nina (weak) |
| SON 2024 | -0.60 | -1.14 | La Nina (weak) |
| ASO 2024 | -0.50 | -1.04 | La Nina (weak) |
| JAS 2024 | -0.40 | -0.94 | Neutral |
| JJA 2024 | -0.30 | -0.84 | Neutral |
| MJJ 2024 | -0.10 | -0.64 | Neutral |
| AMJ 2024 | +0.20 | -0.34 | Neutral |
| MAM 2024 | +0.40 | -0.14 | Neutral |
| FMA 2024 | +0.70 | +0.16 | El Nino (weak) |
| JFM 2024 | +1.10 | +0.56 | El Nino (moderate) |
| DJF 2024 | +1.50 | +0.96 | El Nino (strong) |
| NDJ 2023 | +1.80 | +1.27 | El Nino (strong) |
| OND 2023 | +2.00 | +1.47 | El Nino (very-strong) |
| SON 2023 | +2.00 | +1.47 | El Nino (very-strong) |
| ASO 2023 | +2.00 | +1.47 | El Nino (very-strong) |
| JAS 2023 | +1.80 | +1.27 | El Nino (strong) |
| JJA 2023 | +1.50 | +0.97 | El Nino (strong) |
| MJJ 2023 | +1.10 | +0.57 | El Nino (moderate) |
| AMJ 2023 | +0.80 | +0.27 | El Nino (weak) |
| MAM 2023 | +0.50 | -0.03 | El Nino (weak) |
| FMA 2023 | +0.20 | -0.33 | Neutral |
| JFM 2023 | -0.10 | -0.63 | Neutral |
| DJF 2023 | -0.40 | -0.93 | Neutral |
| NDJ 2022 | -0.60 | -1.12 | La Nina (weak) |
| OND 2022 | -0.70 | -1.22 | La Nina (weak) |
| SON 2022 | -0.80 | -1.32 | La Nina (weak) |
| AMJ 2022 | +0.20 | -0.32 | Neutral |
| MAM 2022 | +0.00 | -0.52 | Neutral |
| FMA 2022 | -0.20 | -0.72 | Neutral |
| JFM 2022 | -0.40 | -0.92 | Neutral |
| DJF 2022 | -0.60 | -1.12 | La Nina (weak) |
| NDJ 2021 | -0.70 | -1.21 | La Nina (weak) |
| OND 2021 | -0.80 | -1.31 | La Nina (weak) |
| SON 2021 | -0.80 | -1.31 | La Nina (weak) |
| ASO 2021 | -0.70 | -1.21 | La Nina (weak) |
| JAS 2021 | -0.60 | -1.11 | La Nina (weak) |
| JJA 2021 | -0.50 | -1.01 | La Nina (weak) |
| MJJ 2021 | -0.50 | -1.01 | La Nina (weak) |
| AMJ 2021 | -0.60 | -1.11 | La Nina (weak) |
| MAM 2021 | -0.80 | -1.31 | La Nina (weak) |
| FMA 2021 | -0.90 | -1.41 | La Nina (weak) |
| JFM 2021 | -1.00 | -1.51 | La Nina (moderate) |
| DJF 2021 | -1.00 | -1.51 | La Nina (moderate) |
| NDJ 2020 | -1.00 | -1.51 | La Nina (moderate) |
| OND 2020 | -0.90 | -1.41 | La Nina (weak) |
| SON 2020 | -0.60 | -1.11 | La Nina (weak) |
| NDJ 2019 | +0.80 | +0.30 | El Nino (weak) |
| JFM 2017 | -0.20 | -0.68 | Neutral |
| DJF 2017 | -0.30 | -0.78 | Neutral |
| NDJ 2016 | -0.50 | -0.98 | La Nina (weak) |
| OND 2016 | -0.60 | -1.08 | La Nina (weak) |
| SON 2016 | -0.70 | -1.18 | La Nina (weak) |
| ASO 2016 | -0.70 | -1.18 | La Nina (weak) |
| JAS 2016 | -0.60 | -1.08 | La Nina (weak) |
| JJA 2016 | -0.40 | -0.88 | Neutral |
| MJJ 2016 | -0.10 | -0.58 | Neutral |
| AMJ 2016 | +0.40 | -0.08 | Neutral |
| MAM 2016 | +0.90 | +0.42 | El Nino (weak) |
| FMA 2016 | +1.60 | +1.12 | El Nino (strong) |
| JFM 2016 | +2.20 | +1.72 | El Nino (very-strong) |
| DJF 2016 | +2.50 | +2.02 | El Nino (very-strong) |
| NDJ 2015 | +2.60 | +2.13 | El Nino (very-strong) |
| OND 2015 | +2.60 | +2.13 | El Nino (very-strong) |
| SON 2015 | +2.50 | +2.03 | El Nino (very-strong) |
| ASO 2015 | +2.20 | +1.73 | El Nino (very-strong) |
| JAS 2015 | +1.90 | +1.43 | El Nino (strong) |
| JJA 2015 | +1.50 | +1.03 | El Nino (strong) |
| MJJ 2015 | +1.20 | +0.73 | El Nino (moderate) |
| AMJ 2015 | +1.00 | +0.53 | El Nino (moderate) |
| MAM 2015 | +0.70 | +0.23 | El Nino (weak) |
| FMA 2015 | +0.50 | +0.03 | El Nino (weak) |
| JFM 2015 | +0.50 | +0.03 | El Nino (weak) |
| DJF 2015 | +0.50 | +0.03 | El Nino (weak) |
| NDJ 2014 | +0.60 | +0.14 | El Nino (weak) |
| OND 2014 | +0.60 | +0.14 | El Nino (weak) |
| DJF 2010 | +1.50 | +1.07 | El Nino (strong) |
| OND 2002 | +1.10 | +0.72 | El Nino (moderate) |
| JFM 1999 | -1.10 | -1.45 | La Nina (moderate) |
| DJF 1999 | -1.50 | -1.85 | La Nina (strong) |
| NDJ 1998 | -1.50 | -1.85 | La Nina (strong) |
| OND 1998 | -1.40 | -1.75 | La Nina (moderate) |
| SON 1998 | -1.20 | -1.55 | La Nina (moderate) |
| ASO 1998 | -1.00 | -1.35 | La Nina (moderate) |
| JAS 1998 | -0.90 | -1.25 | La Nina (weak) |
| JJA 1998 | -0.60 | -0.95 | La Nina (weak) |
| MJJ 1998 | -0.10 | -0.45 | Neutral |
| AMJ 1998 | +0.50 | +0.15 | El Nino (weak) |
| MAM 1998 | +1.00 | +0.65 | El Nino (moderate) |
| FMA 1998 | +1.50 | +1.15 | El Nino (strong) |
| JFM 1998 | +2.00 | +1.65 | El Nino (very-strong) |
| DJF 1998 | +2.30 | +1.95 | El Nino (very-strong) |
| NDJ 1997 | +2.30 | +1.96 | El Nino (very-strong) |
| OND 1997 | +2.40 | +2.06 | El Nino (very-strong) |
| SON 1997 | +2.40 | +2.06 | El Nino (very-strong) |
| ASO 1997 | +2.20 | +1.86 | El Nino (very-strong) |
| JAS 1997 | +1.90 | +1.56 | El Nino (strong) |
| JJA 1997 | +1.50 | +1.16 | El Nino (strong) |
| MJJ 1997 | +1.00 | +0.66 | El Nino (moderate) |
| AMJ 1997 | +0.60 | +0.26 | El Nino (weak) |
| MAM 1997 | +0.30 | -0.04 | Neutral |
| FMA 1997 | +0.10 | -0.24 | Neutral |
| JFM 1997 | +0.00 | -0.34 | Neutral |
| DJF 1997 | -0.10 | -0.44 | Neutral |
| NDJ 1996 | -0.10 | -0.43 | Neutral |
| OND 1996 | -0.20 | -0.53 | Neutral |
| DJF 1992 | +1.60 | +1.30 | El Nino (strong) |
| OND 1987 | +1.60 | +1.33 | El Nino (strong) |
| JFM 1984 | -0.30 | -0.55 | Neutral |
| DJF 1984 | -0.50 | -0.75 | La Nina (weak) |
| NDJ 1983 | -0.60 | -0.84 | La Nina (weak) |
| OND 1983 | -0.60 | -0.84 | La Nina (weak) |
| SON 1983 | -0.50 | -0.74 | La Nina (weak) |
| ASO 1983 | -0.30 | -0.54 | Neutral |
| JAS 1983 | -0.10 | -0.34 | Neutral |
| JJA 1983 | +0.10 | -0.14 | Neutral |
| MJJ 1983 | +0.40 | +0.16 | Neutral |
| AMJ 1983 | +0.80 | +0.56 | El Nino (weak) |
| MAM 1983 | +1.20 | +0.96 | El Nino (moderate) |
| FMA 1983 | +1.60 | +1.36 | El Nino (strong) |
| JFM 1983 | +2.00 | +1.76 | El Nino (very-strong) |
| DJF 1983 | +2.20 | +1.96 | El Nino (very-strong) |
| NDJ 1982 | +2.20 | +1.97 | El Nino (very-strong) |
| OND 1982 | +2.10 | +1.87 | El Nino (very-strong) |
| SON 1982 | +1.90 | +1.67 | El Nino (strong) |
| ASO 1982 | +1.50 | +1.27 | El Nino (strong) |
| JAS 1982 | +1.00 | +0.77 | El Nino (moderate) |
| JJA 1982 | +0.70 | +0.47 | El Nino (weak) |
| MJJ 1982 | +0.50 | +0.27 | El Nino (weak) |
| AMJ 1982 | +0.30 | +0.07 | Neutral |
| MAM 1982 | +0.10 | -0.13 | Neutral |
| FMA 1982 | +0.00 | -0.23 | Neutral |
| JFM 1982 | -0.10 | -0.33 | Neutral |
| DJF 1982 | -0.20 | -0.43 | Neutral |
| NDJ 1981 | -0.40 | -0.62 | Neutral |
| OND 1981 | -0.40 | -0.62 | Neutral |
| DJF 1978 | +0.50 | +0.30 | El Nino (weak) |
| DJF 1975 | -1.00 | -1.18 | La Nina (moderate) |
| DJF 1970 | -0.40 | -0.54 | Neutral |
| DJF 1965 | +1.10 | +0.99 | El Nino (moderate) |
| DJF 1960 | +0.30 | +0.23 | Neutral |
| DJF 1955 | -0.80 | -0.84 | La Nina (weak) |
| DJF 1950 | -1.20 | -1.20 | La Nina (moderate) |