More than a million people across the upper Midwest were under flood warnings on Sunday after days of heavy rain forced evacuations and rescue operations in several states.
The hardest-hit states were Iowa and South Dakota, where water levels in some rivers reached record highs.
South Dakota Governor Kristi Noem said at least one person died in the flooding.
Iowa Governor Kim Reynolds called the flooding “catastrophic” and declared a state of disaster for 21 counties.
Drone footage released by district officials showed homes and buildings almost completely submerged, with only their roofs visible.
In the town of Spencer in northeastern Iowa, water gauges were completely flooded.
“When the flood gauge was underwater, the water levels were very high,” Eric Teagues of Clay County Emergency Management said at a news conference Sunday.
Hundreds of homes in the town were damaged and the city’s sewage treatment plant was flooded, officials said.
Other states with weekend flood warnings include Nebraska, Minnesota, and Wisconsin.
A flood warning means flooding is imminent or ongoing.
Some warnings are expected to end later Sunday, but others will remain in effect until further notice, according to an advisory from the National Weather Service (NWS).
Iowa officials say river levels have exceeded those seen during a 1993 flood that killed 50 people.
This weekend, up to 18 inches (45 centimeters) of rain fell in some areas.
In South Dakota, Gov. Noem declared a state of emergency and warned that the worst flooding was expected on Monday and Tuesday, with the Big Sioux River likely to exceed record levels.
About 4,000 residents in Iowa’s Rock Valley (about 80 kilometers southeast of Sioux Falls) were forced to evacuate on Saturday after water levels in the Rock River rose to record levels.
Rock Valley city officials said residents in the area do not have clean running water because flooding contaminated wells.
Flooding earlier on Saturday left some people and animals stranded in the city, prompting a helicopter rescue operation.
In Wisconsin, severe weather also destroyed a historic church in the village of Argyle, the local diocese said. Apple Grove Lutheran Church, founded in 1893, was completely flattened by a tornado Saturday night.
The storm comes as parts of the U.S. are still dealing with a week-long heat wave that has pushed temperatures past daily records in some cities.
As of Sunday, more than 100 million people were under heat warning alerts. Many alerts are expected to extend into early next week.
During the scorching summer months, with temperatures expected to reach nearly 100 degrees Fahrenheit (37 degrees Celsius) in some areas, the heat wave will affect towns from the mid-Atlantic to the lower Mississippi River basin, all the way to the Great Basin and California.
Temperatures in Oklahoma are expected to reach 107 degrees Fahrenheit (41 degrees Celsius) on Sunday.
The National Weather Service said record high temperatures are also possible in the mid-Atlantic region, including Washington, D.C., and New York City.
Several records were broken on Saturday.
The temperature in Baltimore reached 101 degrees Fahrenheit (38 degrees Celsius), the day’s highest temperature on record since 1988, according to the National Weather Service.
The heat wave arrives unusually early for this time of year, and the National Weather Service warns that for some areas it could be the longest in decades.
Scientists say extreme weather events are becoming more frequent and severe as human-caused climate change is exacerbated by activities such as burning fossil fuels and clearing forests.
The United Nations climate body Intergovernmental Panel on Climate Change (IPCC) says global heat waves have become more frequent and intense since 1950.
