During the past month, sea-surface temperatures across much of the equatorial Pacific Ocean have remained closer to average, which indicates that the El Nino Southern Oscillation (ENSO) phase is at a neutral position and holding steady.
Long-range climate models suggest this neutral phase will remain into fall. As for September temperatures, parts of the Pacific Northwest and northern Rockies are forecasted to see slightly cooler than normal conditions. Total cooling degree-days along with energy costs with respect to cooling for the month are expected to be at least a little lower than average across these regions.
Meanwhile, warmer than normal temperatures are projected from parts of the Midwest down to Texas. This should result in a surplus of late season cooling degree-days by between 30 and 90 across these areas. Cooling costs also likely will be somewhat higher than average. Parts of New England might experience warm weather during September because of a potential positive North Atlantic Oscillation (NAO) index. Mean temperatures are expected to be closer to average across portions of the Southeast, upper Midwest, northern-central plains and central Rockies.