During the past month, sea-surface temperatures across much of the equatorial Pacific Ocean have continued to warm slightly.
This indicates that the weakening of the current La Nina phase is persisting, and a transition to a more neutral phase has begun. Long-range climate models suggest that this transition to a neutral phase will be complete by the end of June, and this neutral phase will remain through at least summer.
As for July, slightly warmer than average readings are expected from the Desert Southwest to parts of the Gulf Coast. Ongoing drought conditions across Texas and portions of the Gulf Coast could further enhance positive temperature anomalies throughout these parts of the country. Total monthly cooling degree-day values are expected to be greater than normal by between 30 and 90.
Cooling costs likely will be higher than normal across these regions. Meanwhile, past climate records from other summer La Nina to neutral phase transition events, especially during 1976, 1989, 2001 and 2008, reveal that near to slightly cooler than average July temperatures are likely across much of the eastern third of the country.
Additional climate model forecasts suggest that parts of the upper Midwest and Great Lakes have the best chance of seeing below-average July temperatures. These areas might see slightly lower than normal cooling costs as a result.