Summer Temperature Outlook: Will An El Niño Cool The East?

Temperatures will be warmer than average across much of the Lower 48 this summer, but are expected to be cooler than last year, a newly released outlook predicted.

A "much different, and cooler, summer is on the way this year," according to Dr. Todd Crawford, Vice President of Meteorology at Atmospheric G2 and author of the latest outlook released Thursday from The Weather Company, an IBM Business, and AG2.

B​efore we get to that summer update, let's first take a look at how next month is shaping up.

May Outlook

Warmer-than-average temperatures are expected in May in parts of the Northeast and along the Gulf Coast into the Carolinas.

Conversely, cooler-than-average temperatures are expected across much of California into Arizona, and temperature could skew slightly cooler than usual in much of the Great Basin and Southwest.

Summer 2023 Outlook

Warmer-than-average conditions will encompass much of the northern half of the country this summer.

Temperatures will be the farthest above average for parts of Montana and North Dakota. Warmer-than-average conditions will extend from parts of the Northwest southward into Oklahoma and eastward into the Great Lakes and northern New England.

The rest of the country should see temperatures near average. Much of the Southeast and parts of California and Arizona will see temperatures that are near average or slightly cooler.

A​nd if you're wondering about rainfall, the most likely scenario is that above average rainfall amounts will occur east of the Rockies while the western states will dry out after a wet, cool winter and early spring.

J​une Outlook

Starting the summer in June, the core of the heat is anticipated to be in parts of the central U.S., while the East will generally experience temperatures near average or slightly warmer.

P​arts of California and Arizona have the highest chance for cooler-than-average temperatures, while parts of the West will be near average.

July Outlook

Warmer-than-average temperatures will also extend from parts of the interior Northwest into the central Rockies, northern Great Lakes and northern New England.

Meanwhile, temperatures will be near average or could even skew slightly cooler over the Ohio Valley, mid-Atlantic and South, including Florida, as well as parts of California.

August Outlook

As summer comes to a close in August, the heat is expected to extend from parts of the West Coast into New England.

Temperatures farthest above average will extend from the Pacific Northwest into the Northern Plains, but a generally hotter-than-average August is expected from the Great Basin to much of the Plains, Midwest and Northeast.

Once again, the Southeast could trend near average or even slightly cooler.

The El Niño Factor

Many factors are used to produce seasonal forecasts.

One that is dramatically different from last summer is a transition from La Niña to El Niño. This is the periodic cooling and warming of the equatorial Pacific Ocean surface temperatures.

T​hese warmer Pacific waters could cause a consistent ridging pattern, or northward bump in the jet stream, over the western U.S., bringing warmer-than-average temperatures to that region. Meanwhile, cooler-than-average conditions would then be expected in the East.

This suggests a generally cooler and wetter than average June-through-August period for much of the contiguous U.S., especially in portions of the East.

Last year's summer was characterized by La Niña conditions bringing temperatures that were far warmer than average to much of the U.S.

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