PREDICTION: 0.70 JUSTIFICATION: Based on the recently reviewed excerpts from the February 2024 ENSO Outlook and additional considerations regarding the current El Niño events transitioning to La Niña, and the reported conditions of sea surface temperatures and upper ocean temperatures across the equatorial Pacific, there is a need to adjust the previously established forecast for July 2024. Therefore, the probability that July 2024 will be the hottest July on record is adjusted to: **PREDICTION: 0.70** The justification for this updated prediction includes the following new insights: - **Transition from El Niño to La Niña Conditions**: The February 2024 ENSO Outlook suggests a transition from El Niño to ENSO-Neutral conditions by April–June 2024, with a subsequent 55% chance for the onset of La Niña during June–August 2024. Historically, the presence of El Niño has been associated with warmer global temperatures due to the increased warming of Pacific sea surface temperatures. A transition to La Niña typically signifies a reversal; however, the impact on global temperatures can lag, and the recent El Niño could have already contributed to elevated global temperatures leading up to July 2024. - **Global Ocean Temperatures**: As of January 2024, sea surface temperatures remained above average across most of the Pacific Ocean. These elevated temperatures contribute to a higher baseline from which further temperature anomalies can arise, thereby increasing the likelihood of experiencing record-high global temperatures in July 2024. - **Undersea Temperature Dynamics**: The noted shift towards near-average temperatures in the upper 300 meters of the equatorial Pacific for the first time in almost a year, alongside the expansion of cooler-than-average waters, indicates significant dynamical changes within the ocean. These changes could have far-reaching effects on global climate patterns, potentially influencing atmospheric circulation patterns and contributing to abnormal temperature distributions globally. - **Historical Context of Rapid Transitions**: The analysis indicating that a strong El Niño event, such as the one experienced, often rapidly transitions to La Niña conditions, without extensive intervening ENSO-neutral conditions, points to the dynamic and volatile nature of current global climate systems. This volatility enhances the potential for extreme weather and temperature conditions, including the possibility of setting new temperature records. Given these considerations, it seems prudent to adjust the forecast probability slightly higher to 0.70, reflecting the accumulated effects of a strong El Niño transitioning rapidly to potentially La Niña conditions, alongside current above-average sea and undersea temperatures. This adjustment acknowledges the complex interplay between oceanic and atmospheric conditions that could contribute to an increased likelihood of July 2024 being the hottest July on record. It is important to note that while this forecast adjustment attempts to integrate the latest insights from ENSO dynamics, inherent uncertainties in climate forecasting and the evolving nature of these ocean-atmospheric phenomena remain. These should be taken into account, and forecasts should be updated as new data and analyses become available.