ENSO: El Niño and La Niña Events in the Niño 3.4 Region

This time-series dataset tracks El Niño and La Niña events through monthly sea surface temperature (SST) measurements in the east-central equatorial Pacific. Published via HDX and derived from NOAA Climate Prediction Center data, it provides historical records updated through March 2026. The data includes standardized Oceanic Niño Index (ONI) values and specific event classifications based on sustained temperature anomalies.

Use Cases

• Predicting climate phase transitions (phase_event) using historical sea surface temperature anomalies (ANOM)
• Analyzing the impact of 30-year base period adjustments (ClimAdjust) on temperature trends
• Correlating 3-month rolling means (ANOM_trimester) with regional weather patterns

Strengths

• Uses standardized ERSST.v5 sea surface temperature data
• Provides pre-calculated 3-month rolling means (ANOM_trimester)
• Includes binary event classification (phase_event) based on the 5-consecutive-trimester rule

Limitations

• Limited to the Niño 3.4 region of the Pacific Ocean
• Monthly temporal resolution may mask short-term atmospheric fluctuations
• Relies on 30-year base period adjustments which may shift historical anomaly values

Provenance

Source

NOAA Climate Prediction Center (CPC)

Collection Method

Sensor-based sea surface temperature measurements and statistical processing

Time Range

Historical records through 2026

Freshness

Updated through March 2026.

Geography

East-central equatorial Pacific (Niño 3.4 region)