Saturday brought as much rain in one day as Portlanders usually see throughout the entire month of August.

It was the second rainiest day of the year in Portland with .80 inches of rain, second only to January 18, which received 1.11 inches of rain, the National Weather Service’s Portland Twitter account reported.

The downpour selectively wetted the metro area, with the Portland International Airport area receiving most of the onslaught and other areas receiving barely any rainfall at all. The weather service, in the same thread about the rainfall, noted that the north and east sides of the metro area received the most rain, while areas like Hillsboro received only .01 inches of rain.

“That is one of the more impressive things,” Matthew Cullen, a National Weather Service meteorologist based in Portland, said on Saturday. “Most of the rain today fell within 90 minutes to two hours, and it wasn’t the entire area seeing rain. We had some very strong showers from around the Portland airport and east to Interstate 205, but there were parts of town in the south, as well as Milwaukie and Happy Valley, that had very little rain.”

The Weather Service reported that the rain also broke the record for August 10 historically. The historic record rain total for August 10 in Portland was set at 0.36 inches in 1957.

The Portland Bureau of Environmental Services said Saturday that the heavy rains had caused a sewage overflow at Northwest 110th Avenue and Front Avenue in Portland; initial estimates say the overflow leaked 60,000 gallons of stormwater and sewage into the Willamette River.

“Because of increased bacteria in the water, the public should avoid contact with the Willamette River in the vicinity of Linnton and Port of Portland Terminal 4 and downstream for the next 48 hours,” the bureau said.

The statement reported that this is the first sewage overflow of 2019 and noted that sewage overflows in Portland are increasingly rare because of investments in the city’s drainage system.

--Casey Chaffin; cchaffin@oregonian.com; @todaycaseysays

Michael Russell contributed to this report.