Summer of extreme weather continues, with deadly floods in Kentucky and St. Louis, and a heat-wave emergency in Oregon

• Record heat and flooding are the latest extreme weather events in the US this summer.
• Four people are dead following floods in Kentucky and St. Louis.

Extreme weather events have dominated this summer in the US, with some regions seeing record-breaking heat, while others experienced fatal flooding. Both events are becoming more common and more severe because of the climate crisis.

After torrential rainfall in St. Louis earlier in the week, eastern Kentucky saw storms that brought devastating flooding to areas of the state. As of Thursday afternoon, three people were confirmed dead from the floods.

"I expect double-digit deaths in this flooding," Kentucky Gov. Andy Beshear said.

Less than 48 hours earlier, a man in St. Louis died after flash flooding submerged his car in more than 8 feet of water, the St. Louis Post-Dispatch reported. More than 9 inches of rain fell in just 24 hours, the highest rate in St. Louis history, delivering more than 25% of the city's average annual rainfall in just 12 hours, according to the National Weather Service.

Area fire departments rescued more than 400 people during the flood, while 10 puppies drowned at a dog-rescue center in a St. Louis suburb, the newspaper reported.

Parts of the city's light-rail system were damaged in the flood when waters covered the tracks. Residents who use the damaged areas of the public transit system were advised to seek alternate transportation "until further notice," likely for two weeks, according to the Post-Dispatch.

The impact of Tuesday's rainfall and flooding is expected to be felt by St. Louis residents for weeks, the St. Louis Post-Dispatch reported.

Meanwhile, residents of the Pacific Northwest are coping with grueling heat. The governor of Oregon declared a state of emergency in 25 of the state's counties on Tuesday, with temperatures expected to top 100 degrees for most of the week, KGW8 reported. In western Washington, temperatures on Tuesday broke records.

More than 85 million Americans were under heat warnings as of Sunday, NPR reported.

"I encourage everyone to take proactive steps to keep themselves and their families safe, including drinking plenty of fluids, taking advantage of cooling centers, and checking in on neighbors, friends, and loved ones," Oregon Gov. Kate Brown said in a statement.

Heat in the region isn't expected to let up for the rest of the week, ABC News reported. Parts of California, Nevada, and Idaho are under heat alerts until Saturday.

Temperatures are climbing, and rainfall is changing

Climate change, driven by all the greenhouse gasses that humans have released into the atmosphere, is changing the planet's water cycle. Rising temperatures are increasing water evaporation and changing the atmospheric and ocean currents that distribute moisture across the globe. In some places, drought is becoming more common, extreme, or prolonged. In others, like the US Midwest, heavy rainfall and flooding are increasing.

Because it raises temperatures across the globe, climate change also makes heat waves more common, severe, and long-lasting, and spreads them over a larger geographic area. Scientists have already observed these changes in heat waves over the last few decades, and they expect extreme heat to keep getting more dangerous and more prevalent in the future.

This year is perfectly demonstrating the trend. The US has been bombarded with record-breaking heat waves, some lasting two weeks or longer, since spring. Europe, China, the Middle East, North Africa, and much of South and Central Asia have also suffered repeat extreme-heat events this year.

Across the Mediterranean region, other parts of Europe, and the US, the heat dried out the landscape and fueled major wildfires — another type of extreme weather that's becoming more common and severe in many parts of the world as the planet's temperatures rise.

"We're in a climate that is constantly shifting towards more extremes. From that perspective, it's exactly what we would expect, and what scientists have projected to happen for the last decade," Kai Kornhuber, a climate physicist at Columbia University, told Insider in mid-July.

Seattle's previous record temperature for July 26 was 92 degrees, but this year it reached 94 degrees, according to the National Weather Service. The city of Bellingham saw a 4-degree increase, from its 1988 record of 86 degrees, to this year's 90 degrees.

"Extreme heat is a deadly hazard we will see more of in Seattle as a result of climate change," Curry Mayer, Seattle's director of emergency management, said in a statement. "We ask residents to take extreme heat seriously by understanding the danger and learning how to protect yourself, your family, and your neighbors."

Meteorologists don't expect temperatures to climb as high as they did during the devastating heat event that caused more than 1,400 deaths in the Pacific Northwest last year. The 2021 event would have been "virtually impossible" without climate change, according to a historical data analysis by World Weather Attribution.

"We don't have to go down this path," Kornhuber said, calling for a rapid reduction in greenhouse-gas emissions. "But if things keep developing the way they are, it's pretty clear that we will see more record-breaking extremes, and more concurrent extremes just as this year, and even more extreme."