From California to parts of central U.S., where heat will be intense this week (2024)

The National Weather Service office in Hanford, which serves much of California’s Central Valley, is warning of a “dangerous, prolonged heat wave that will last several days with Extreme Heat Risk through this week of Fourth of July.”

Heat advisories run from eastern Kansas to East Texas, then across the northern Gulf Coast region through the Florida Panhandle. Oklahoma City, Dallas and Tallahassee are in the heat advisory area, generally for heat indexes up to 110 degrees.

At least 45 million Americans are likely to be subjected to actual high temperatures at or above 100 degrees this week. Over two-thirds of the population will experience 90 degrees, often on many days.

The new HeatRisk product forecasts a Level 4 of 4 extreme threat to affect at least 20 states through the next seven days. More than two dozen states have significant coverage of a Level 3 of 4 major threat.

Typically sultry New Orleans basks in drippy distress again on Tuesday. Heat indexes of 112 to 118 will be common, according to the local Weather Service office. Actual temperatures will reach the mid-90s to near 100. Heat indexes around 115 are also anticipated in Tulsa and surrounding areas. Memphis is expecting heat indexes up to 113 Wednesday.

A long, punishing and dangerous heat spell is also revving up in California. Tuesday temperatures should end up about 105 to 110 for highs in the Central Valley, with nearer 110 to 115 common in desert areas to the south.

Even areas typically cooled by the ocean may feel the heat. That’s because of a stunted marine layer of clouds and fog due to the heat dome overhead. Heat advisories include San Francisco itself, where temperatures should reach the 80s. Other coastal areas are under heat warning for temperatures around 100.

In parts of the west, fire weather will also be of concern. Red flag warnings are up in sections of central California. Several large fires are burning amid a fast start to the season in these regions.

In portions of Kansas through Oklahoma and into Texas on Tuesday, temperatures of 100 to 105 degrees will also be widespread. Heat gets kicked farther south mid- and late week, while somewhat below-average temperatures settle into the central Plains by the end of the week, probably only for a short time.

Heat will be building in much of the eastern United States heading into the holiday period. Independence Day looks like a scorcher from the Mid-Atlantic through the Southeast and back to Texas. A majority of spots from D.C. south and west shoot for the mid- or upper 90s, with higher heat indexes.

It should stay similar in these regions into the weekend, with perhaps an occasional decrease in day-to-day temperatures outside the Southeast, in part due to potentially heightened rain risks.

By the Fourth of July, highs near and above 110 are likely to remain common in the Central Valley of California, the deserts of that state and into neighboring Arizona as well as southern Nevada. It could turn even hotter Friday and Saturday, with spots in the Central Valley approaching 120.

“Far inland areas may actually end up with triple digits into the weekend and the start of the next week,” wrote the Weather Service office serving the San Francisco Bay Area.

Little change is expected through the weekend. Temperatures may rise toward 90 as far north as the Seattle region, with 100-plus forecast for eastern Washington state.

It was the hottest June on record in many places, such as the Intermountain West, South Texas and parts of New England. Some broad areas surrounding those locations witnessed one of their top-five hottest Junes.

July is primed to keep going. Hundreds of daily record highs and record warm lows are on the chopping block this week, from coast to coast.

Record highs begin to increase in number Tuesday through Thursday, then several days with dozens of record highs are possible up and down the West Coast. Occasional record highs will also be possible in the central and eastern United States.

“A few climate sites may flirt with all-time temperature records,” wrote the Weather Service office serving the Las Vegas area, where temperatures are forecast to rise to about 115, with lows near 90 late week.

Notable targets include Redding in Northern California. The Weather Service is currently forecasting 118 there on Friday, which would tie the all-time record, set previously on dates in late July and early August. Temperatures in Mount Shasta and other nearby locations may also threaten all-time records, perhaps on more than one day in some cases.

Las Vegas is expecting multiple days of 115 or higher. The forecast there for next Monday is 117, which would tie the all-time maximum in the city. Palm Springs could reach 120. Much of the Central Valley will rise near 110 for days on end.

Death Valley — one of the hottest places on earth — is staring down an evil week of weather and has a decent chance to reach the highest temperature recorded by modern instrumentation.

Forecast highs there from Tuesday through Monday are: 119, 125, 127, 128, 129, 130 and 130. The hottest temperature observed there is 134, although there are questions about its reliability. In 2020 and 2021, Death Valley reached 130 degrees, the highest reliably observed temperature on record. It also reached 129 in 2023.

Considerably more impressive in coverage, there will be dozens of daily record warm lows, maybe rising to more than 100 of them on several days through the weekend. Phoenix and Las Vegas could experience 90-plus lows, while many other locations remain at or above 80. Record warm nights are a leading symptom of human-caused climate change and a major magnifier of danger from heat waves.