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Mid-Summer to Early-Fall Temperatures Are Expected to be Mild in the Central U.S., Hot Near the Coasts
Published: June 25, 2019
Relatively cool temperatures in the middle of the country and relatively warm ones toward the coasts are anticipated to prevail for most areas through the start of fall, according to an outlook released Thursday by The Weather Company, an IBM Business.
This general temperature theme has dominated much of the United States since May.
Record precipitation is one of the main drivers for the cooler temperatures in parts of the West, Plains and Midwest, noted Dr. Todd Crawford, chief meteorologist at The Weather Company.
Soil moisture continues to be well above average for much of the Plains, and in summer that can greatly influence temperatures. When the landscape is wet, some of the solar energy that would heat the land and the air near the ground is instead used for evapotranspiration, the process that transfers water to the atmosphere and pulls water from vegetation back to the air. As a result, temperatures can be cooler than they would be otherwise.
The upper-level pattern in place recently in the North Atlantic may continue through the rest of the summer. This suggests that the Southeast would be the warmest pocket of the nation relative to the averages for July through September.
Weak El Niño conditions are also persisting, which suggests that below-average temperatures are more likely in the northern Plains and Great Lakes and above-average temperatures are likely across the southern tier of the U.S. and the Northwest.
Here's a closer look at how the forecast evolves over the next three months.
In July, below-average temperatures are expected from northern Arizona and Utah into the central Plains, while a broad area of near- to slightly below-average temperatures is possible from Southern California into the Midwest.
Temperatures will be the most above average across the Florida Peninsula, while much of the South, East and West Coast can expect near- or slightly above-average conditions.
The reason for a largely mild July is the "combination of the North Atlantic blocking signal, record soil-moisture levels and continued weak El Niño conditions," Crawford said.
The coolest temperatures compared to average are likely from eastern Wyoming and northeastern Colorado into southern North Dakota, southwestern Minnesota, Iowa and northwestern Missouri.
Meanwhile, areas toward the East and West coasts can expect above-average temperatures.
Elsewhere from the Midwest into parts of the South and West, temperatures will be closer to average for the last month of summer.
As fall begins, the overall temperature pattern may trend a bit warmer.
Warmer-than-average conditions are anticipated across the East and northern tier into the Northwest. Temperatures will be closer to average or slightly warmer for much of the Midwest, lower Mississippi Valley and parts of the West.
Temperatures may run cooler than average from New Mexico and Colorado into southwestern Iowa and Missouri.
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.