Station list     Available data
ILLINOIS RIVER BASIN


415755087525300       O'HARE AIRPORT AT CHICAGO, IL



LOCATION.-- Latitude 41°57'55", longitude 87°52'53", in NE1/4NW1/4NW1/4 sec.16, T.40 N., R.12 E., Cook County, Hydrologic Unit 07120004, on Montrose Road 500 ft West of Mannheim Road, and located on the fence 100 ft past a guard house of the O'Hare Airport at Chicago.

PERIOD OF RECORD.--
PRECIPITATION: October 1, 1998 to current year.

GAGE.-- An 8-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, 2.92 in., (estimated) October 17, 1998.

EXTREMES FOR CURRENT YEAR.--Maximum daily total, 2.84 in., August 30.

PRECIPITATION, TOTAL, INCHES, WATER YEAR OCTOBER 2000 TO SEPTEMBER 2001
DAILY SUM VALUES
DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP
1 0.00 0.00 0.31 0.00 s0.01 0.00 0.00 0.00 0.52 0.00 0.00 0.00
2 .00 .14 .00 .00 .00 .00 .00 .00 .03 .00 .84 .00
3 .91 .00 .00 .00 .00 .20 .00 .00 .00 .05 .00 .00
4 .31 .00 .00 .00 s.02 s.19 .00 .00 .00 .00 .00 .00
5 .09 .00 s.11 s.05 .00 s.18 .27 .00 .53 .00 .00 .00
6 .01 .84 s.05 s.06 s.06 .00 .21 .17 .00 .00 .00 .87
7 .06 .00 s.06 s.03 s.03 .00 .00 .04 .00 .34 1.53 .00
8 .00 .05 .00 s.06 .63 .00 .00 .00 .00 .00 .00 .00
9 .00 .92 .00 s.05 .41 .00 .14 .00 .00 .00 .35 .23
10 .00 .00 .05 s.05 s.06 .05 .00 .34 .00 .00 .00 .00
11 .00 .00 s.01 s.40 s.03 .05 .52 .37 .30 .00 .00 .00
12 .00 .01 .00 s.07 s.19 .15 .00 .00 .08 .00 .00 .00
13 .00 .23 .00 .00 .01 .00 .00 .00 .00 .00 .01 .00
14 .01 .00 s.01 .11 .21 .00 .00 .12 .60 .00 .01 .00
15 .03 .12 .00 .02 .00 .35 .30 .00 .01 .00 .07 .00
16 .00 .01 .17 .00 .00 .13 .00 .31 .00 .00 .54 .00
17 .00 .00 .00 .00 s.02 .22 .00 .01 .10 .21 .00 .22
18 .00 .00 s.03 s.02 s.01 .00 .00 .00 .21 .01 .89 .66
19 .00 .01 .00 .00 .00 .00 .00 .00 .01 .00 .38 1.14
20 .00 .00 .00 s.06 s.01 .00 .27 .07 .00 .00 .00 e1.14
21 .00 .00 .00 .00 s.01 .00 .36 .24 .12 .00 .06 e.08
22 .00 .00 s.01 s.01 .00 .00 .10 .03 .01 1.05 .59 .00
23 .00 .03 .00 s.09 .00 .00 .40 .04 .00 .02 .05 e.66
24 .01 .00 .00 s.02 1.05 .00 .00 .23 .00 .00 .39 .01
25 .00 .15 s.02 s.03 .50 .00 .00 .07 .00 .58 .87 .00
26 .00 .10 .00 .00 s.01 .00 .00 .66 .00 .00 .00 .00
27 .00 .00 .00 s.01 s.20 .00 .00 .12 .00 .00 .22 .00
28 .00 .00 s.01 .00 s.01 .00 .00 .12 .00 .00 .00 .00
29 .00 .06 .00 .61 -- .00 .00 .00 .00 .00 .00 .00
30 .00 .00 .00 .17 -- .00 .00 .00 .00 .00 2.84 .00
31 .00 -- .00 .02 -- .02 -- .41 -- .00 .02 --

TOTAL 1.43 2.67 0.84 1.94 3.48 1.54 2.57 3.35 2.52 2.26 9.66 5.01

s Snowfall-affected precipitation
e Estimated


Table of Contents

Introduction

Station Descriptions

Surface-Water Data

Ground-Water Data

Meteorological Data

Biological Data