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Triple-digit temperatures expected for July 4 holiday; nearly 150 million people under heat alert

Triple-digit temperatures expected for July 4 holiday; nearly 150 million people under heat alert

Triple-digit temperatures expected for July 4 holiday; nearly 150 million people under heat alert

Heat warnings and alerts are in effect for nearly 150 million people in 21 states over the holiday period, with dangerous and potentially historic extreme heat expected to hit the West in the coming days and temperatures of 115 degrees possible.

Several daily heat records were broken on Tuesday and more than 130 could be set by next Tuesday.

The California cities of San Rafael and Livermore hit record high temperatures on Wednesday, at 100 and 110 degrees respectively.

Excessive heat warnings are in effect for much of California and southern Nevada, as well as parts of Arizona, Washington and Oregon. An excessive heat warning means life-threatening conditions, “with high to very high risk for much of the population due to long-lasting heat with little to no overnight relief.”

The National Weather Service in the San Francisco Bay Area warned that “an exceptionally dangerous situation is developing as we head into a potentially historic and deadly heat event.”

He said heat is the leading cause of weather-related death in the United States and that “we are VERY LIKELY to increase that statistic if preparations are not taken seriously.”

The extreme heat in the San Francisco area could last six to 12 days, the local weather service said, making it the longest period of extreme temperatures the Bay Area has experienced in at least 18 years.

The city of Los Angeles issued an excessive heat warning on Wednesday, saying the period of scorching temperatures could last “at least” through Monday, with temperatures potentially climbing to 106 in parts of Los Angeles “for many days in a row.”

In Oregon, where temperatures are expected to reach near-record levels this weekend, Gov. Tina Kotek issued a warning Wednesday and said state agencies were working to open cooling centers to combat the heat wave.

And Seattle’s weather service warned Wednesday that the forecast for a hot holiday weekend remains intact, with highs in the 90s, peaking Sunday.

In the Plains and Southeast, the heat index, which measures how windy it feels when humidity is taken into account, could reach between 100 and 115 on Wednesday.

The heat index could reach 116 degrees in Little Rock, Arkansas, while in Phoenix it is expected to reach 113 on the same scale.

On Wednesday, Little Rock officially hit 100 degrees for the first time this year, 301 days since the mercury last rose this high in the city.

Phoenix hit a high temperature of 113 degrees on Wednesday, the 16th consecutive day the city has seen temperatures at or above 110 degrees.

Phoenix police said a child died Tuesday while hiking on South Mountain “as a result of a heat-related medical issue.” The police department said the victim’s family had been on the trail since earlier in the day.

According to the weather service, the Southern Plains and Lower Mississippi Valley are likely to experience “stifling heat and humidity” through the holidays, with temperatures reaching the upper 90s and low 100s and heat indices reaching 110 degrees. The heat wave is expected to spread eastward to the Mid-Atlantic by the end of the week.

Several cities have already canceled or postponed Fourth of July fireworks ceremonies and parades due to high temperatures and dry conditions that could lead to wildfires.

In California, St. Helena announced it would postpone its fireworks show until later in the year when weather conditions are better. And Oroville canceled its Fourth of July fireworks, citing the Thompson Fire, which has been burning nearby since Tuesday.

Antioch, California, canceled its daytime parade because of the heat but said it still planned to hold a fireworks show Thursday night.

Excessive heat and humidity will extend from Nashville, Tennessee, to New Orleans on Wednesday and Thursday, but slightly cooler temperatures will arrive on Friday.

It’s already been a record-breaking year for temperatures. It’s only the beginning of July, but Miami has spent more time with temperatures of 105 degrees or higher than it did in all of 2019.

Extreme heat increases the risk of wildfires. About 4 million people, most of them in California, are under red flag warnings. The warnings urge people to be careful around open flames, an added risk with holiday fireworks shows taking place.

There is also a chance that stormy weather in the central US could disrupt some holiday gatherings.

Approximately 13 million people are at risk from severe storms in the western High Plains and Ohio River Valley. Strong winds are likely in both areas, along with hail and isolated tornadoes in the region.

On Thursday, 6 million people are at slight risk of severe storms across much of Missouri and parts of Kansas and Oklahoma.

A secondary area of ​​thunderstorms that could flare up in the afternoon could be Iowa, where tornadoes are possible. The main threat will be damaging winds for cities like Kansas City, Missouri, and Topeka, Kansas.

A low-pressure front over the central High Plains and a frontal boundary stretching from the lower Great Lakes to the central Plains could be “the triggers for some meteorological fireworks,” the weather service said.

Flash flooding is possible as a result of heavy rainfall between eastern Kansas and the Ohio Valley.

This article was originally published on NBCNews.com