Climate Plots for Northern Illinois and Northwest Indiana

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	DuPage Airport	Midway Airport	O'Hare Airport
Chicago Executive Airport	Rockford Airport	NWS Romeoville	Waukegan Airport
Valparaiso Airport

**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:

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.

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.