LOCATION.-- Latitude 41°51'31", longitude 88°14'36" (NAD of 1927), in NW1/4SW1/4SW1/4 sec.17, T.39 N., R.9 E., Du Page County, Hydrologic Unit 07120004, on McChesney Road 0.5 mi north of Eola Road, and at the National Accelerator Lab near West Chicago.

PERIOD OF RECORD.--

PRECIPITATION: April 1989 to October 1995 and July 1997 to current year.

GAGE.-- A 12-in.-diameter, unheated, 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, 5.09 in., July 9, 2002.