ENSO state and its historical imprint on rainfall and temperature in the 77 CVF-V20 member countries across Africa, Asia, the Caribbean, Latin America and the Pacific. All statistics are computed from public observational datasets, with significance testing and multiple-testing control.
List from cvfv20.org (accessed 7 October 2026). Click a country to open its page.
Latest weekly OISST anomaly; purple mark: record ONI
ONI (bars) and weekly Niño 3.4 (line), °C
Status and period of every source
Weekly and monthly state of the tropical Pacific and the full ONI record, extended before 1950 from ERSSTv5.
Sea surface temperature anomalies (°C, 1991-2020 base), last 104 weeks
3-month running mean of ERSSTv5 Niño 3.4 anomalies: NOAA CPC from 1950, same method recomputed on the ERSSTv5 grid before (shaded); RONI as a line when available
CPC definition: at least 5 consecutive overlapping seasons with ONI ≥ +0.5 °C or ≤ -0.5 °C
Strength by peak |ONI|: weak 0.5-0.9, moderate 1.0-1.4, strong 1.5-1.9, very strong ≥ 2.0 °C.
Where and when ENSO shifts rainfall and temperature in CVF-V20 countries. Detrended country seasonal series; significance is controlled across all countries (false discovery rate).
Solid bars: significant after false discovery rate control (Benjamini-Hochberg, q = 0.10); light bars: not significant. Click a bar to open the country in the explorer.
Correlation between the ONI and seasonal rainfall (or temperature), for all 12 overlapping 3-month seasons. ●: p < 0.05 (two-sided t-test, no multiple-testing correction).
For each member country: seasonal cycle, ENSO-coloured history, sensitivity to the ONI, lagged predictability and the historical odds of a dry or wet season.
ONI centred L months before the centre of the target season (L = 0: same season), detrended series
Dashed: 5 % significance threshold. A significant correlation at a 3-6 month lag means that today's ONI carries predictive information for this season.
Frequency of below-, near- and above-normal seasons (terciles of the detrended record)
Probability of a below-normal (dry or cool) or above-normal (wet or warm) season in each country, combining an ENSO scenario with the country's historical response (Mason and Goddard 2001 approach).
How did each member country fare during past strong El Niño events (NDJ ONI ≥ 1.5 °C)? Each season is compared with ENSO-neutral seasons after removing the trend, event by event.
November-January ONI of each strong event; hatched: current state
Everything on this page is reproducible with the open pipeline update_data.py.