Summer weather split

Forecasters now see a split U.S. summer through August: cooler odds in parts of the Northeast and Great Lakes, hotter odds across much of the West and South. (weather.com) The Weather Company and Atmospheric G2 said Thursday that June through August should run hottest in the Northwest and northern Rockies, with above-average heat also favored from Texas to Florida. Their outlook also points to wetter-than-average conditions for the Southwest monsoon later in summer. (weather.com) In the Northeast and northern Great Lakes, the same outlook shows temperatures may come in a bit below average, with cooler air showing up along the Eastern Seaboard in June and again in parts of the Great Lakes by August. May is also projected to skew cooler from the Northern Plains to New England. (weather.com) A seasonal outlook is not a day-by-day forecast. The National Oceanic and Atmospheric Administration says these maps show the odds that a month or a three-month period will finish above, near, or below the long-term average. (climate.gov) Those outlooks are built from ocean and atmosphere patterns, model guidance, recent trends, and historical analogs. The Climate Prediction Center says forecasters compare current conditions with past years that looked similar before assigning those probabilities. (climate.gov) The biggest climate signal in this forecast is El Niño, the periodic warming of the equatorial Pacific that can shift jet stream patterns far from the tropics. On April 9, the Climate Prediction Center said neutral conditions were still in place, but gave El Niño a 61 percent chance of emerging in May through July 2026 and persisting through at least the end of the year. (cpc.ncep.noaa.gov) Federal forecasters have not issued a June-through-August map matching Weather.com’s regional split, but the Climate Prediction Center’s March 19 long-lead discussion already leaned cooler for parts of the Great Lakes and Northeast in spring while favoring above-normal temperatures across much of the rest of the contiguous United States. It also said El Niño was likely to emerge in June through August 2026. (cpc.ncep.noaa.gov) The same federal discussion favored above-normal precipitation for the eastern Great Lakes, the mid-Atlantic, and parts of the Southeast in April through June, while tilting drier in the Pacific Northwest, the Intermountain West, and the Rockies. That lines up with a summer setup in which the West’s heat risk stays elevated even if some Southwest monsoon areas turn wetter later on. (cpc.ncep.noaa.gov; weather.com) The forecast will change as ocean temperatures and wind patterns evolve into June and July. The next federal El Niño diagnostic is scheduled for May 14, 2026, and that update will show whether the summer split is sharpening or fading. (cpc.ncep.noaa.gov)