The intense rain last night flooded the parking lot in the Kencho (prefectural government office building). The caption says the photo was taken a little after 11 PM on the 20th.

The article also says that Kosa-machi got a record-breaking 150 millimeters (almost 6 inches) of rain in just an hour last night.

http://www.asahi.com/articles/photo/AS20160621000059.html