A weekslong heat wave will intensify this weekend and push temperatures close to 130 degrees

An already dangerous weekslong heat wave will only worsen this weekend as a heat dome intensifies and reaches peak strength over parts of the Western United States.

The heat dome is so formidable the National Weather Service in Phoenix called it "one of the strongest high pressure systems this region has ever seen." Around 100 heat records could fall today through the weekend as it intensifies, piling onto the more than 1,000 high temperature records broken in the US since June.

More than 90 million people are under heat alerts after the heat dome expanded into places like California, which is now experiencing its first extreme heat wave of the year.

It has already been dangerously hot for weeks in Texas, Florida and Arizona, where Phoenix is in the middle of a likely record-breaking streak of consecutive 110-degree days, forcing many businesses and parks to close or readjust their hours. The low temperature in Phoenix might not drop below 90 degrees for eight consecutive days, another record.

The heat will be so intense, forecasters suggested residents of Las Vegas avoid the outdoors between 9 a.m. and 6 p.m., with the city forecast to challenge its all-time high temperature of 117 degrees on Sunday. It won't get much cooler at night, with low temperatures nearing 90 degrees - a particularly dangerous side effect of the climate crisis.

Even the hottest place on Earth, California's Death Valley, could reach rare highs, with 130 degrees possible Sunday, forecasters at the National Weather Service told CNN. It has only happened a handful of times, one of which is the all-time global record high temperature of 134 degrees.

This kind of extreme heat is one of the hallmarks of human-caused climate change, the symptoms of which are tallying up this year into a global record box score of sorts: "unprecedented" ocean heat off the coast of Florida and in the North Atlantic; record heat in Beijing, in what could be one of the hottest summers in China; record energy demand and heat in Texas; and an ongoing "Cerberus" heat wave, threatening to topple European temperature records.