The National Weather Service in Hanford, which serves much of California’s Central Valley, warned that a “dangerous, extended heat wave with the risk of extreme heat will continue for several days through this week leading up to the Fourth of July.”
Heat watches are in effect from eastern Kansas to eastern Texas, then across the northern Gulf Coast and through southern Georgia and western Florida. Oklahoma City, Dallas, Houston, Mobile, Alabama, and Tallahassee are under heat watches, with heat index temperatures typically reaching 110 degrees Fahrenheit.
At least 45 million Americans could be exposed to temperatures that actually exceed 100 degrees this week, with more than two-thirds of the population experiencing temperatures above 90 degrees, often for multiple days at a time.
The new HeatRisk product predicts an extreme Level 4 threat for at least 14 states over the next seven days, with a widespread Level 3 severe threat in about 24 states.
Where the heat is strongest early in the week
Normally muggy New Orleans will be hit with rain on Monday. According to the local weather service, a heat index of 112 to 118 is typical, with actual temperatures reaching the mid-90s F. In Tulsa and surrounding areas, the heat index is expected to be around 115.
California is experiencing a long, brutal and dangerous heatwave Monday, with highs approaching 100 degrees in the Central Valley and 100 to 110 degrees being the norm in the southern desert.
Areas that are normally cooled by the ocean may also feel hotter because the marine cloud and fog layers are disrupted by the thermal dome overhead.
Fire weather is also a concern in parts of the West, particularly in California and the Great Basin. Red flag warnings have been issued for parts of central California and southwestern Utah, where several large fires are burning early in the season.
Temperatures will be widespread Monday and Tuesday, reaching at least 100 degrees Fahrenheit in locations from Kansas to Oklahoma and Texas. The heat will move farther south through the mid-to-late week, with slightly below average temperatures taking hold across the Central Plains over the weekend, but likely only for a short time.
Future hot spots
Heat will be on the rise across much of the eastern U.S. as we approach the holiday season. Independence Day will be a scorching hot day from the Mid-Atlantic to the Southeast and into Texas. Most locations will see temperatures rise into the mid to upper 90s Fahrenheit and heat indexes will be high.
Similar weather conditions are expected to continue across these regions into the weekend, but outside the Southeast there may also be an increased risk of rain, which could result in occasional drops in daily temperatures.
By the Fourth of July, temperatures are expected to frequently reach nearly 110 degrees in California’s Central Valley, the state’s desert regions, and neighboring Arizona and southern Nevada.
“Triple-digit temperatures are possible inland through the weekend and into next week,” the weather service, which serves the San Francisco Bay area, wrote.
Little change in temperatures is expected over the weekend, with temperatures likely to reach nearly 90 degrees north of the Seattle area and over 100 degrees in eastern Washington.
Record temperatures approaching
Many locations, including the mountain west, south Texas, and parts of New England, experienced their hottest June on record, and large areas surrounding these locations recorded one of the top five hottest Junes ever.
July is not over yet, with hundreds of new daily high and low temperature records expected across the US this week.
Several record high temperatures are possible each day early in the week, with numerous daytime records likely to be broken Thursday through Sunday. The potential record high temperatures will be concentrated overwhelmingly in California and parts of neighboring states, although occasional records could also be broken in the central and eastern United States.
“Some weather stations may approach record high temperatures,” wrote the National Weather Service, which serves the Las Vegas area, where temperatures are expected to rise to about 115 degrees later in the weekend, with lows near 90.
Notable targets included Redding in Northern California hitting about 115 degrees, much of the Central Valley nearing 110 degrees on consecutive days, Las Vegas nearing 115 degrees on multiple days and the Southeast coast nearing 100 degrees at times.
Death Valley, one of the hottest places on Earth, is expecting severe weather this week that could approach the highest temperatures ever recorded with modern measuring instruments.
The predicted high temperatures for Monday through Sunday are 118, 122, 125, 127, 128, 128, and 129. The highest observed temperature is 134, but reliability is questionable. In 2020 and 2021, Death Valley reached 130 degrees, the highest temperature reliably observed on record. In 2023, it even reached 129 degrees.
If coverage is widespread enough, record high low temperatures could reach the tens of degrees each day, with the number potentially topping 100 on several days over the weekend. Low temperatures above 90 degrees could be recorded in Phoenix, while many other places will see temperatures above 80 degrees. Record high nights are a prime indicator of human-induced climate change and a major factor in increasing the risk of heat waves.
