LOCATION.-- Latitude 41°50'37", longitude 87°58'17" (NAD of 1927), in SW1/4NE1/4NW1/4 sec.27, T.39 N., R.11 E., Du Page County, Hydrologic Unit 07120004, on Midwest Road 50 ft north of U.S. Highway 88, and located on the roof of the Oakbrook well housing, at Oak Brook.

PERIOD OF RECORD.--

PRECIPITATION: July 1997 to current year. Prior to Water year 2003, published as "Oak Brook Lift Station at Oak Brook, IL."

GAGE.-- A 12-in.-diameter, heated, tipping-bucket rain gage.

REMARKS.-- Snowfall-affected data can result during cold weather when snow fills the rain-gage funnel and then melts as temperatures rise. Snowfall-affected data are subject to appreciable errors.

EXTREMES FOR PERIOD OF RECORD.--

PRECIPITATION: Maximum daily total, 2.90 in, October 17, 1998.