heat Thursday
Hot temperatures for the South as Great Salt Lake sees historic low
02:43 - Source: CNN
CNN  — 

The third heat wave of the still-early summer is scorching the US South, and “it will get worse … before it gets better,” warns the National Weather Service.

Over 65 million people across 16 states are under heat alerts Thursday, with triple-digit heat indexes – or “feels like” temperatures – expected in cities including Dallas; St. Louis; Memphis, Tennessee; Little Rock, Arkansas; Birmingham, Alabama; Atlanta; and Raleigh, North Carolina.

The latest heat wave continues a trend playing out in recent weeks on every continent in the Northern Hemisphere – and something that will be more frequent with human-induced climate change, experts with the Copernicus Climate Change Service said Thursday.

Above-normal temperatures will soar Thursday into the upper 90s and 100s Fahrenheit from the central and southern Plains to the Southeast. Paired with uncomfortable high humidity, it will feel like 110 to 115 degrees in some places.

And above-normal temperatures are forecast well into next week across the South – well beyond the average of four days. Dallas already has seen several days above 100 degrees and is expected to continue the trend though at least midweek, putting this stretch in the running for the city’s longest consecutive 100-degree streak since 2011.

“Just as concerning, low temperatures will remain very warm overnight providing little relief from the sweltering conditions during the day,” the Weather Prediction Center said.

Over 100 warm, low-temperature records could be tied or broken over the next three mornings, with lows in the mid-70s to low-80s. Memphis and Tulsa, Oklahoma, are a few of places with overnight lows expected to stay above 80 degrees.

“Excessive heat is especially dangerous for vulnerable populations,” the prediction center warns.

NEW YORK - JULY 10:  A man wipes sweat from his face July 10, 2007 in New York City. New York City is experiencing a second day of a heat wave with temperatures in the upper 90`s and uncomfortable humidity levels.  (Photo by Spencer Platt/Getty Images)
Nighttime 'lows' more dangerous than highs
01:07 - Source: CNN

Heat is the No. 1 cause of weather-related deaths in the United States, and people in places where the temperature is due to spike should be on the lookout for heat-related ailments, including cramps, exhaustion and stroke. Heat even can kill.

Excessive heat also can damage crops, injure or kill livestock, and increase wildfire risk. And it can lead to power outages as increased demands for air conditioning strain the power grid, the Environmental Protection Agency has said.

Global heat waves result from a warming climate

The latest US heat wave adds to a series of global heat waves related to the warming climate, said the Copernicus Climate Change Service monthly report. The globe this year experienced the third-warmest June on record as early summer heat waves impacted parts of Europe, Asia and North America, it said.

In the regions where these heat waves occurred – non-tropical land areas of the Northern Hemisphere – June temperatures have been warming about twice as fast as they have globally since the 1970s, the report noted.

Dozens of heat records were broken last month across the United States, Western Europe, Japan and northern China.

The eastern and central US baked for much of June amid back-to-back heat waves. The stubborn heat dome led to hundreds of records from the Plains to the South.

A location in southern France topped 40 degrees Celsius (104 degrees Fahrenheit) on June 16 – the earliest mainland France had ever reached that mark. Days later, several locations across the country broke June temperature records, and a few even set all-time records.

Japan ended the month with a record-breaking heat wave that also included the nation’s earliest 40-degree temperature – a record that was set in 1875.

The heat waves in Europe and Asia are exceptional but not unexpected, the Copernicus report said.

“In line with the evidence presented in the latest (Intergovernmental Panel on Climate Change) Assessment Report, there is an increase in the frequency and intensity of heatwaves and that this rise, according to the IPCC, can be attributed to human-induced climate change and is expected to continue in the future as the climate continues to warm globally,” the Copernicus report said.

“Heatwaves similar to those observed this year are expected to become more frequent and severe in the years to come, both in Europe and further afield,” said Carlo Buontempo, director of the Copernicus Climate Change Service.