The National Weather Service office in Hanford, which serves much of California’s Central Valley, is warning of a “dangerous and prolonged heat wave that will last several days with a risk of extreme heat through this week of the 4 July “.
Heat advisories extend from eastern Kansas to eastern Texas and then across the northern Gulf Coast region to southern Georgia and the Florida Panhandle. Oklahoma City; Dallas; Houston; Mobile, Ala.; and Tallahassee are in the heat advisory zone, generally for heat indices up to 110 degrees.
At least 45 million Americans are at risk of being exposed to high temperatures of 100 degrees or higher this week. More than two-thirds of the population will experience temperatures of 90 degrees, often on multiple days.
This new HeatRisk product forecasts a Level 4 of 4 extreme threat impacting at least 14 states over the next seven days. About two dozen states have significant coverage of a Level 3 of 4 major threat.
Where the heat is most intense to start the week
Usually sweltering New Orleans basks in a humid atmosphere Monday. Heat indexes of 112 to 118 will be common, according to the local weather service office. Actual temperatures will reach the mid 90s. Heat indices around 115 are expected in Tulsa and surrounding areas.
A long, harsh and dangerous heat wave is also intensifying in California on Monday, with highs expected to reach nearly 100 degrees Celsius in the Central Valley, with 100 to 110 degrees Celsius in the southern desert areas.
Even areas typically cooled by the ocean can feel the heat. This is due to a stunted marine layer of clouds and fog due to the thermal dome above us.
In parts of the West, particularly California and the Great Basin, wildfire risks will also be a concern. Red fire warnings have been issued in parts of central California and southwestern Utah. Several large fires are burning in these areas as the season gets off to a fast start.
Parts of Kansas, Oklahoma and Texas will also see temperatures near 100 degrees on Monday and Tuesday. The heat will spread farther south by mid-week and late-week, while slightly below-average temperatures will settle into the central Plains by the end of the week, likely for only a short period.
Hot spots for the next few days
The heat will rise across much of the eastern United States as the holiday season approaches. Independence Day is expected to be scorching from the Mid-Atlantic to the Southeast and all the way to Texas. Most areas are aiming for temperatures around 32 or 35 degrees with higher heat indices.
The situation is expected to remain similar in these regions through the weekend, with perhaps an occasional drop in daily temperatures outside the Southeast, partly due to potentially increased rain risks.
Between now and July 4, temperatures near 110 will likely remain common in California’s Central Valley, that state’s deserts, neighboring Arizona as well as southern Nevada.
“Remote inland areas could actually see triple-digit numbers over the weekend and early next week,” the weather service office serving the San Francisco Bay Area wrote.
Little change is expected over the weekend. Temperatures could rise to 90 degrees Fahrenheit (32 degrees Celsius) as far north as the Seattle area, and exceed 100 degrees Fahrenheit (38 degrees Celsius) in eastern Washington state.
Record temperatures ahead
It was the hottest June on record in many places, such as the Mountain West, South Texas, and parts of New England. Some large areas surrounding these locations experienced one of their five warmest Junes.
July is ready to continue. Hundreds of record daily warm highs and lows are poised to be in jeopardy this week, from coast to coast.
Several heat records are possible each day at the start of the week and from Thursday to Sunday, many daily records could be broken. Potential heat records are primarily concentrated in California and parts of neighboring states, although records will also be possible in the central and eastern United States at times.
“A few climate sites could flirt with historical temperature records,” wrote the weather service office serving the Las Vegas area, where temperatures are expected to reach around 115°F, with lows near 90°F by the end of the week.
Notable targets include Redding in Northern California around 115, much of the Central Valley near 110 for days, Las Vegas on several days around 115 and the southeast coast at times near 100.
Death Valley, one of the hottest places on Earth, is facing a week of unfavorable weather and has a chance of flirting with the highest temperature recorded by modern instruments.
The high temperatures forecast Monday through Sunday are: 118, 122, 125, 127, 128, 128 and 129. The highest temperature observed there is 134, although doubts remain about its reliability. In 2020 and 2021, Death Valley reached 130 degrees, the highest temperature ever reliably recorded. It also reached 129 in 2023.
Even more impressive, the heat records could number in the dozens of daily minimum temperatures, possibly reaching over 100 on multiple days over the weekend. Phoenix, for example, will see minimum temperatures above 90 degrees, while many other places will remain at 80 degrees or above. Record-breaking hot nights are a leading symptom of human-caused climate change and a major amplifying factor in the danger of heat waves.
