National Weather Service United States Department of Commerce

Heavy Rains and Potential for Flash Floods

Severe thunderstorms with damaging winds and heavy rains will be possible from the Ohio Valley to the Northeast Tuesday. In addition, heavy rains possible in the central Plains and southern Rockies. Heavy rain threat moves into the southern Mid-Atlantic Wednesday. Dry conditions remain out west where isolated dry thunderstorms could exacerbate ongoing fires and start new fires. Read More >

 


Climate data on this page is PRELIMINARY (unofficial). CERTIFIED (official) climate data is available from the National Climatic Data Center or the Midwestern Regional Climate Center.  
 


Graphs of observed temperatures and precipitation are available from several airport stations from around northern Illinois and northwest Indiana. These are available for individual months, and the year to date.  Go to the bottom of the page for help on how to interpret these graphs.

 

Last 31 Days:

Aurora Airport
Last 31 Days in Sugar Grove

DuPage Airport
Last 31 Days in West Chicago

Midway Airport
Last 31 Days at Midway Airport

O'Hare Airport
Last 31 Days at Chicago O'Hare

Chicago Executive Airport
Last 31 Days in Palwaukee

Rockford Airport
Last 31 Days at Rockford Airport

NWS Romeoville
Last 31 Days in Romeoville

Waukegan Airport
Last 31 Days in Waukegan

Valparaiso Airport
Last 31 Days in Valparaiso

 

2017 Graphs:

Aurora Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
DuPage Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Midway Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
O'Hare Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Palwaukee Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Rockford Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Romeoville NWS Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Waukegan Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Valparaiso Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

 

2016 Graphs:

Aurora Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
DuPage Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Midway Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
O'Hare Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Palwaukee Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Rockford Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Romeoville NWS Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Waukegan Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Valparaiso Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

 

 

2015 Graphs:

Aurora Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
DuPage Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Midway Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
O'Hare Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Palwaukee Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Rockford Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Romeoville NWS Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Waukegan Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Valparaiso Airport Annual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

 

 

For specific daily observations, visit https://www.weather.gov/climate/index.php?wfo=lot and select the "Preliminary Climatological Data (CF6)" option. 


Here are descriptions on how to interpret these graphs:

 

Climate plot for Chicago O'Hard for July 2015

This is an example of the monthly climate plot.  The observed high and low temperatures are indicated by the tops and bottoms of the vertical blue bars, respectively.  The normal temperature ranges are indicated by the green band.  Record highs are shown on the top of the light pink band, and record lows are indicated along the bottom of the light blue band.

 

Chicago O'Hare climate data for 2014

This is an example of the year to date climate plot.  As with the monthly plot, observed temperatures are shown by the dark blue areas, normals with the light green areas, record highs in the light red areas, and record lows in the light blue areas.

The bottom portion of the graph indicates the precipitation and snowfall for the year to date.  The yellow line (and green area below it) represents the normal year to date total at the given time frame.  Periods that have year to date totals above the climatological normals are shown by dark green areas above the yellow line.  Periods that are below normal are shown with the brown areas below the yellow line.