TERRA ElNiñoCast analyzes detrended historical ERA5 precipitation and temperature data using the Relative Oceanic Niño Index (RONI) to pinpoint which months and regions are impacted by El Niño and La Niña. It shows only statistically significant anomalies and not random noise. Select from the following phases to check whether climate conditions are affected:

• Neutral: All historical Neutral Phases (RONI between -0.5 and +0.5)
• El Niño: All historical El Niño Phases including weak, moderate and strong El Niños (RONI above +0.5)
• La Niña: All historical La Niña Phases including weak, moderate and strong La Niña (RONI below -0.5)
• Moderate El Niño: Only historical moderate El Niño Phases (RONI between +0.5 and +1.5)
• Moderate La Niña: Only historical moderate La Niña Phases (RONI between -1.5 and -0.5)
• Strong El Niño: Only historical strong El Niño Phases (RONI above +1.5)
• Strong La Niña: Only historical strong La Niña Phases (RONI below -1.5)

⚠️ Note: Strong El Niño and La Niña phases occur less frequently in the historical record. Selecting these narrower phases means fewer years are available for analysis, which can make results statistically less robust than broader phase selections.