How much did it rain in Sioux Falls on July 23?

A storm brought heavy rain and flash flooding to parts of eastern South Dakota, including Sioux Falls, on July 23.

The National Weather Service issued a flash flood warning for Sioux Falls and the surrounding region shortly after 6 p.m., as storms moved into the area from the southwest.

The call log for the Sioux Falls Police Department shows multiple calls for stalled vehicles and other traffic hazards around that time.

How much did it rain in Sioux Falls and other South Dakota cities on July 23?

In Sioux Falls, reports of rainfall totals ranged from 0.63 inches on the west side of the city to 4.84 inches on the east side, according to the Community Collaborative Rain, Hail & Snow Network.

Here’s how much rain fell in other South Dakota cities:

• Aberdeen: 0.69 inches
• Brookings: 0.01 inches
• Elk Point: 0.61 inches
• Harrisburg: 2 inches
• Hurley: 0.09 inches
• Lennox: 1.16 inches
• Milbank: 0.55 inches
• Mitchell: 0.03 inches
• Sisseton: 0.87 inches
• Tea: 1.47 inches
• Vermillion: 1.09 inches
• Watertown: 1.3 inches
• Yankton: 0.12 inches

What is flash flooding?

Flash flooding usually begins within six hours, but often within three hours, of heavy rain or massive amounts of water accumulating in an area, according to the National Weather Service.

This type of flooding usually happens very quickly and catches people off guard. It can be caused by a number of things, but it is often due to extremely heavy rainfall from thunderstorms.

“The intensity of the rainfall, the location and distribution of the rainfall, the land use and topography, vegetation types and growth/density, soil type, and soil water-content all determine just how quickly the flash flooding may occur, and influence where it may occur,” the National Weather Service says.