Published: June 30,2017
July could be a hot month for a large swath of the western and northern United States, according to the latest outlook from The Weather Company, an IBM Business.
It appears a significant El Niño will not develop this year, so it's not a factor in the forecast this summer. The state of the atmosphere is still tilting a bit toward the La Niña event that occurred over the winter.
"The July forecast is now warmer across the northern U.S., given the lack of any sign of high-latitude blocking and the persistence of the weak La Niña base state," said Dr. Todd Crawford, chief meteorologist with The Weather Company.
The biggest heat relative to average in July is likely to remain anchored in the Southwest where a prolonged heat wave set numerous record highs in the second half of June. The central High Plains are also forecast to see temperatures that are much above average.
July temperature outlook.States from the Midwest into New England also have increased odds of seeing above-average temperatures overall in July.
Although the Southeast is forecast to see temperatures slightly below average, typical summer heat and humidity can still be expected.
(MAPS: Average Monthly Temperatures)
What to Expect in August and SeptemberMost areas east of the Rockies could see temperatures near or slightly above average in August. The Northwest is the only area favored to see cooler-than-average temperatures during the month.
But Crawford cautions that the north-central and northeastern regions could see hotter temperatures than currently forecast if negative NAO conditions do not develop at times.
"Our August-September maps have a La Niña look, with less heat across the north-central and northeastern states due to concerns about negative NAO conditions developing again," said Crawford.
August temperature outlook.The transition from summer to fall in September may be marked by above-average warmth spreading across the nation's southern tier, as well as northward toward the Great Lakes and mid-Atlantic.
Cooler-than-average readings are forecast to be locked in once again in the Northwest.
September temperature outlook.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.