Heat Wave Expands to the East Coast; Flash Flooding Likely in the Central Plains into the Midwest; Severe Thunderstorms in the Northeast

Dangerous, prolonged heat is ongoing in the Mid-South to Mid-Mississippi Valley and heat expands into the Northeast for a brief period today. Widely scattered instances of flash flooding due to heavy rains are forecast from northeast Kansas to much of Indiana. Scattered strong to severe thunderstorms are possible across parts of New England, northern Mid-Atlantic, and North Dakota. Read More >

Chicago
Rockford

Weather Observations for the City of Chicago

Official Climate Observation Sites

Location	Occupied From	Occupied To	Remarks
181 W Washington St. (formerly 162 Washington St.)	10/15/1870	10/8/1871	Station abandoned on October 8, 1871 due to the Great Chicago Fire – all records lost.
427 W Randolph St. (10 W Randolph St. prior to 1909)	10/14/1871	6/11/1872	Room rented on October 14. Regular observations resumed on October 16.
20 N Wacker Dr. (80 S Market prior to 1909)	6/11/1872	6/8/1873
Roanoke Building (formerly Major Block) SE corner of Madison St. and LaSalle St.	6/8/1873	1/1/1887
Chicago Opera House SW corner of Clark St. and Washington St.	1/1/1887	2/1/1890
Auditorium Tower NE corner of Wabash Ave. and Ida B. Wells Dr./Congress Pkwy.	2/1/1890	7/1/1905	Automatic recording rain gauge installed in 1897
U.S. Court House 219 S Dearborn St. Photo 1* \| Photo 2*	7/1/1905	12/31/1925	Maintained supplemental observations through October 15, 1970
University of Chicago Rosenwald Hall 58th St. and University Ave. Photo*	1/1/1926	6/30/1942	Maintained supplemental observations through March 31, 1962
Midway International Airport South Terminal Building 6200 S Cicero Ave.	7/1/1942	1/17/1980	Supplemental observations were transferred to station Midway Airport 3SW
O’Hare International Airport International Terminal Building	1/17/1980	3/7/1985
O’Hare International Airport Hardstand Operational Building	3/7/1985	1/19/1989
O’Hare International Airport O’Hare Corporate Tower, Rosemont	1/19/1989	2/1/1996
O’Hare International Airport	2/1/1996	Present	Automated Surface Observing System (ASOS) installed

*Photos provided to the NWS by long time weather observer Frank Wachowski.

Additional Climate Records (but not official for Chicago)

Location	Occupied From	Occupied To	Remarks
U.S. Court House 219 S Dearborn St.	1/1/1926	10/15/1970	Previously was the official observation site for Chicago. Observations continued local site’s climate record.
University of Chicago Rosenwald Hall 58th St. and University Ave.	1/1/1916 and 7/1/1942	12/31/1925 and 3/31/1962	Temporarily was the official observation site for Chicago. Observations continued local site’s climate record.
University of Chicago 5730 S Woodlawn Ave.	4/1/1962	10/31/1994	Previously was the official observation site for Chicago. Observations continued local site’s climate record.
Midway International Airport National Airtransport Hangar 5490 S Cicero Ave.	2/13/1928	11/3/1932
Midway International Airport South Terminal Building 6200 S Cicero Ave.	11/3/1932	6/30/1942	Continuation of MDW climate records. Became the official observation site for Chicago on 7/1/1942.
Midway Airport 3SW (Cooperative Observer)	1/18/1980	Present	Continuation of MDW climate records after the official observation site for Chicago was transferred to O’Hare
Midway International Airport	5/1/1997	Present	Regular observations resumed at Midway Airport after an Automated Surface Observing System (ASOS) was installed
O’Hare International Airport International Terminal Building	10/30/1958	1/16/1980	Beginning of ORD climate records. Became the official observation site for Chicago on 1/17/1980.

Weather Observations for the City of Rockford

Official Climate Observation Sites

Location	Occupied From	Occupied To	Remarks
900 Block, N Main St.	12/??/1872	10/??/1893	Cooperative observer, T. D. Robertson (rainfall only)
731 N Court St.	11/??/1893	12/??/1912	Cooperative observer, H. C. Porter (rainfall only)
1135 N Court St.	1/??/1913	6/1/1918	Cooperative observer, Dr. John R. Porter (temperature observations added)
731 N Court St.	6/2/1918	7/29/1920	Cooperative observer, Carson H. Porter
324 Churchill St.	7/30/1920	12/19/1950	Cooperative observers, F. W. Knowlton and Daughter
Rockford Airport Federal Facilities Building	12/19/1950	7/1/1995
Rockford International Airport	7/1/1995	Present	Automated Surface Observing System (ASOS) installed

Additional Climate Records (but not official for Rockford)

Location	Occupied From	Occupied To	Remarks
324 Churchill St.	12/19/1950	9/23/1953	Cooperative observers. Previously was the official observation site for Rockford.
2221 North Winnebago St.	9/24/1953	6/30/1957	Continuation of the same cooperative observer's climate record at a new residence.

LOT RSS Feed

Heat Wave Expands to the East Coast; Flash Flooding Likely in the Central Plains into the Midwest; Severe Thunderstorms in the Northeast

History of the Chicago and Rockford Weather Observation Sites