Mid to Late Summer Outlook: Warm Temperatures to Prevail, Especially in the North

Tom Moore
Published: June 22,2016
Most of the U.S. will experience above-average temperatures from mid to late summer, according to the latest outlook by The Weather Company, an IBM Business.
The most extreme warmth is expected to extend from the northern Rockies to the Great Lakes, said Dr. Todd Crawford, chief meteorologist with The Weather Company.
"Given the fact that summers transitioning from El Niño to La Niña get hotter as the summer progresses, this sets a rather interesting tone for the rest of the season," Crawford said.
The trend for above average temperatures across a large portion of the nation will already be in place by July. The only exceptions, where temperatures will be a bit below average, will be along the Gulf Coast and Florida.
The core of the heat will be from the northern Rockies to the Great Basin in July.

Temperature Forecast For July.

Summer Forecast: July-September 

The trend of warmer-than-average temperatures overall during summer months the last several years is expected to continue.
"The last six summers have been the hottest six-year stretch in the last 120 years, barely eclipsing the very hot 1930s," Crawford said.
The only area where cooler-than-average temperatures are expected will be southern Texas, the western Gulf Coast and southern Florida.

Temperature Forecast For July-September.

"We expect that the full La Niña forcing will come roaring into play by July and, especially, August," Crawford said. "We expect a strongly 'back-loaded' summer with the heat continuing into September."
Typically, La Niña summers feature hotter temperatures from the central U.S. into the Northeast.
Crawford notes that during previous years where rapid changes from El Niño to La Niña occurred, the worst of the summer heat was focused from the northern Plains to the Great Lakes states.
Another factor to consider regarding temperatures this summer are sea-surface temperatures in the western North Atlantic, which are forecast to be warmer than any time over the past five years.
That often results in warmer temperatures in the eastern U.S.
Overall, computer model guidance indicates widespread warmth with little hint of cooler-than-average temperatures across most of the nation.
Keep in mind that these outlooks are overall trends for the season. An individual cold front or an upper ridge of high pressure can lead to a brief period of colder or warmer weather, respectively.