Last Sat. a new 24 hour rainfall record was set in Chicago 8.2 inches.  Here's what's happened just this last week.

Such heavy rains are extremely unusual, said Harry Hillaker, state of Iowa climatologist.

"To see 10 inches of rain in one spot - a single gauge area - happens about once every 800 years," Hillaker said. "That is very extreme in one spot."

The deluge comes just more than a year after more than 10 inches of rain fell in Oelwein over a 12-hour period on July 22 and 23, 2010. The heavy rains in the Maquoketa River basin contributed to the Lake Delhi dam failure July 24.

• In northwestern Illinois, Galena recorded 13.45 inches;
• A spot four miles southwest of Dubuque gauged 15.1 inches.
• Another area four miles southeast of the city measured 14.5 inches.
• THE MONTHLY RAINFALL TOTAL FOR JULY
  2011 TO 11.15 INCHES AS OF 7 AM CDT. THIS SETS A NEW RECORD FOR THE
  WETTEST JULY IN RECORDED HISTORY IN CHICAGO.

If you think you’ve seen a downpour, consider this: Over a 40-hour period starting at midnight July 26, Seoul was inundated with 17.5 inches of rain, according to Bloomberg.

Seoul ended up with over 20 inches for the week, another city received 26 inches. Korea has nothing in it's record books like this event.

Then the storm got to Japan -

Forecasters warned that the rains could continue to be torrential after reaching 1,000 millimetres (40 inches) to date in Sanjo City, Niigata, 250 kilometres (155 miles) northwest of Tokyo, since they started Wednesday.

In Fukushima Prefecture,The Meteorological Agency said some areas in the two prefectures saw precipitation of 100 mm per hour and warned that torrential rain would continue through Saturday morning.

40 inches of rain falling at rates of as high as 4 inches an hour.