[NOAA Logo] NCDC / Climate-Radar Data Inventories / Locate Station / Search ------------------------------------------------------------------------ Chicago Ohare International Airport * About this Station Chicago, IL, United States * Data Inventories Other Stations in Chicago * DATA List Stations in Division IL-02 * Station History List Stations in Cook County * State Climatologist List Stations within 5, 10, 25, or 50 miles * Regional Climate Center Type* : ASOS-NWS FCWOS --------------------------- Information at Other Sites Call : ORD / KORD * National Weather Service Sign/ICS* - Central Region WBAN* : 94846 Headquarters COOP ID* : 111549 - Regional Forecast Office Climate Division* : IL-02 - Northeast - Current Weather Conditions WMO ID* : 72530 - Current Weather Forecast In Service* : 30 Oct 1958 to Present * Current Radar Elevation* : 200.6m (658.0') above s/l * Current Satellite Lat/Lon* : 41¢X59'N / 87¢X55'W * Sunrise/Sunset County* : Cook * Disclaimer * List of NCDC Datasets * Please report any Data Errors found. * Note to webmasters: you can link directly to this page. ------------------------------------------------------------------------ [Go to Top of Page] Other Stations in Chicago Chicago / Waukegan Waukegan Reg Chicago / West Chicago Dupage A Chicago / Wheeling Pal - Waukee A Chicago 95th / Baltimore Chicago Botanical Garden Chicago C Wtr Filt Plant Chicago Cal Treat Wks Chicago Christiana Av Chicago Dan Ryan Woody Chicago Dunne Crib Chicago Grant Park Chicago Hanover Park Chicago Hazelcrest Chicago Heights Chicago Homewood Chicago Lake Calumet Chicago Lakeview Pump Chicago Lawrence / Calif Chicago Loyola Univ Chicago Mayfair Pump Station Chicago Meigs Field Chicago Midway Airport Chicago Midway Ap 3 SW Chicago N Bra Pump Station Chicago Oak Lawn Chicago Orland Park Chicago Racine Pump Chicago Roseland Pump Chicago S Wtr Filt Plant Chicago San Dist Office Chicago San Dist Office Chicago Springfld Pump Chicago University Chicago WSFO Chicago Wb City 2 Chicago Yacht Club Chicago Yacht Club Bh Lansing Municipal Airport Romeoville Lewis Univ Airport ------------------------------------------------------------------------ [Go to Top of Page] About this Station Chicago is located along the southwest shore of Lake Michigan and occupies a plain which, for the most part, is only some tens of feet above the lake. Lake Michigan averages 579 feet above sea level. Natural water drainage over most of the city would be into Lake Michigan, and from areas west of the city is into the Mississippi River System. But actual drainage over most of the city is artificially channeled also into the Mississippi system. Topography does not significantly affect air flow in or near the city except that lesser frictional drag over Lake Michigan causes winds to be frequently stronger along the lakeshore, and often permits air masses moving from the north to reach shore areas an hour or more before affecting western parts of the city. Chicago is in a region of frequently changeable weather. The climate is predominately continental, ranging from relatively warm in summer to relatively cold in winter. However, the continentality is partially modified by Lake Michigan, and to a lesser extent by other Great Lakes. In late autumn and winter, air masses that are initially very cold often reach the city only after being tempered by passage over one or more of the lakes. Similarly, in late spring and summer, air masses reaching the city from the north, northeast, or east are cooler because of movement over the Great Lakes. Very low winter temperatures most often occur in air that flows southward to the west of Lake Superior before reaching the Chicago area. In summer the higher temperatures are with south or southwest flow and are therefore not influenced by the lakes, the only modifying effect being a local lake breeze. Strong south or southwest flow may overcome the lake breeze and cause high temperatures to extend over the entire city. During the warm season, when the lake is cold relative to land, there is frequently a lake breeze that reduces daytime temperature near the shore, sometimes by l0 degrees or more below temperatures farther inland. When the breeze off the lake is light this effect usually reaches inland only a mile or two, but with stronger on-shore winds the whole city is cooled. On the other hand, temperatures at night are warmer near the lake so that 24-hour averages on the whole are only slightly different in various parts of the city and suburbs. At the O'Hare International Airport temperatures of 96 degrees or higher occur in about half the summers, while about half the winters have a minimum as low as -l5 degrees. The average occurrence of the first temperature as low as 32 degrees in the fall is mid-October and the average occurrence of the last temperature as low as 32 degrees in the spring is late April. Precipitation falls mostly from air that has passed over the Gulf of Mexico. But in winter there is sometimes snowfall, light inland but locally heavy near the lakeshore, with Lake Michigan as the principal moisture source. The heavy lakeshore snow occurs when initially colder air moves from the north with a long trajectory over Lake Michigan and impinges on the Chicago lakeshore. In this situation the air mass is warmed and its moisture content increased up to a height of several thousand feet. Snowfall is produced by upward currents that become stronger, because of frictional effects, when the air moves from the lake onto land. This type of snowfall therefore tends to be heavier and to extend farther inland in south-shore areas of the city and in Indiana suburbs, where the angle between wind-flow and shoreline is greatest. The effect of Lake Michigan, both on winter temperatures and lake-produced snowfall, is enhanced by non-freezing of much of the lake during the winter, even though areas and harbors are often ice-choked. Summer thunderstorms are often locally heavy and variable, parts of the city may receive substantial rainfall and other parts none. Longer periods of continuous precipitation are mostly in autumn, winter, and spring. About one-half the precipitation in winter, and about l0 percent of the yearly total precipitation, falls as snow. Snowfall from month to month and year to year is greatly variable. There is a 50 percent likelihood that the first and last l-inch snowfall of a season will occur by December 5 and March 20, respectively. Channeling of winds between tall buildings often causes locally stronger gusts in the central business area. However, the nickname, windy city, is a misnomer as the average wind speed is not greater than in many other parts of the U.S. ------------------------------------------------------------------------ [Image] Data Inventories Please note that additional data (digital and non-digital) may be available for this station. Contact NCDC if additional details are needed. Click on the following where available: o DAT to obtain digital ascii data (charges may apply), Please do not order these data if you do not know what a Digital ASCII File is. o INV to view inventory, or o DOC to view documentation Surface DAT INV DOC 3200 -Cooperative Summary Of The Day DAT INV DOC 3210 -Summary Of The Day - First Order DAT INV DOC SOD -Daily Surface Data (TD3200/3210 combined) DAT INV DOC 3220 -Summary Of The Month (SOM) Cooperative DAT INV DOC 3240 -Hourly Precipitation Data DAT INV DOC 3280 -Surface Airways Hourly And Airways Solar Radiation DAT INV DOC 3290 -Summary Observation DAT INV DOC 3292 -Weather Duration DAT INV DOC 9950 - (see Global Surface Station Information). ------------------------------------------------------------------------ [Go to Top of Page] DATA Additional data products may be available for this station. If you can't find what you are looking for here, please try our Most Popular Products page. Forms, Publications, and Web Pages Graphs and Other Images CD-ROMs Digital ASCII Files ------------------------------------------------------------------------ [Go to Top of Section] Forms, Publications, and Web Pages Most of these products are publications that have been converted to on-line access. As such, these documents have column headings and are displayed in an easy-to-read format. For additional information and product samples, click on the [Question Mark Icon, Click for Additional Information About this Product] icon next to the desired product. [Question Mark Icon, Click for Additional Information About this Product] Hourly Surface Weather Observations (Form 10A/B) [Question Mark Icon, Click for Additional Information About this Product] Hourly Precipitation Data for Illinois [Question Mark Icon, Click for Additional Information About this Product] Hourly/Daily Data, Local Climatological Data (Unedited) [Question Mark Icon, Click for Additional Information About this Product] Hourly/Daily Data, Local Climatological Data (Edited) [Question Mark Icon, Click for Additional Information About this Product] Daily/Monthly/Annual Illinois Climatological Data [Question Mark Icon, Click for Additional Information About this Product] Record of Climatological Observations [New] [Question Mark Icon, Click for Additional Information About this Product] Annual Climatological Summary [New] [Question Mark Icon, Click for Additional Information About this Product] Storm Data Publication [Question Mark Icon, Click for Additional Information About this Product] Miscellaneous Storm Events in Cook County ------------------------------------------------------------------------ [Go to Top of Section] Graphs and Other Images Includes contour maps, time series, NEXRAD radar mosaics, and satellite images. For additional information and product samples, click on the [Question Mark Icon, Click for Additional Information About the Product] icon next to the desired product. [Question Mark Icon, Click for Additional Information About this Product] National Mosaic Reflectivity Images [Question Mark Icon, Click for Additional Information About this Product] Miscellaneous Satellite Images [Question Mark Icon, Click for Additional Information About this Product] Graph Weather Elements using CLIMVIS Period of Record Elements Available 1958-11 thru 1998-07: ABCDEFGHIJKLMNOP Please ensure that the parameters you enter are within the parameters specified in the above table. Otherwise you will receive no data. Element 1 Element 2 Year/Month ------------------------------------------------------------------------ [Go to Top of Section] CD-ROMs The following are some of the more popular CD-ROMs that contain data for this station. Others are available that may contain summarized data for this station. A complete list of CD-ROMs is available in the OnLine Store. For additional information, click on the [Question Mark Icon, Click for Additional Information About this Product] icon next to the desired product. [Question Mark Icon, Click for Additional Information About this Product] Hourly U.S. Weather Observations, 1990-1995 [Question Mark Icon, Click for Additional Information About this Product] NCDC Cooperative Station Data [Question Mark Icon, Click for Additional Information About this Product] Solar and Meteorological Surface Observational Network [Question Mark Icon, Click for Additional Information About this Product] U.S. Hourly Precipitation Data ------------------------------------------------------------------------ [Go to Top of Section] Digital ASCII Files These files may or may not contain column headers. In order to use these files, you will need to import them into a spreadsheet or database package for presentation. Please do not order these data if you do not know what a Digital ASCII File is. A sample Digital ASCII File is available for viewing but content varies a great deal depending on your request. Other digital files are available Offline that may contain data for this station. For additional information and product samples, click on the [Question Mark Icon, Click for Additional Information About this Product] icon next to the desired product. [Question Mark Icon, Click for Additional Information About this Product] SOD -Daily Surface Data (TD3200/3210 combined) [Question Mark Icon, Click for Additional Information About this Product] 3220 -Summary Of The Month (SOM) Cooperative [Question Mark Icon, Click for Additional Information About this Product] 3240 -Hourly Precipitation Data ------------------------------------------------------------------------ [Go] Station History Chicago Ohare International Airport Date Date Elevation COOP Call WMO Began Ended Lat/Lon meters/feet ID WBAN Sign ID Type CHICAGO OHARE INTL AP 20 Aug Present 41¢X59'N / 200.6m / 111549 94846 ORD 72530 ASOS-NWS 1997 87¢X55'W 658.0' FCWOS 01 Feb 20 Aug 41¢X59'N / 200.6m / 111549 94846 ORD 72530 ASOS-NWS 1996 1997 87¢X55'W 658.0' WSCMO 01 Apr 01 Feb 42¢X00'N / 200.6m / 111549 94846 ORD 72530 WSCMO 1995 1996 87¢X53'W 658.0' 01 Jan 01 Apr 42¢X00'N / 200.6m / 111549 94846 ORD 72530 WSO 1995 1995 87¢X53'W 658.0' 03 Dec 01 Jan 42¢X00'N / 200.6m / 111549 94846 ORD 72530 WSO 1991 1995 87¢X53'W 658.0' 19 Jan 03 Dec 42¢X00'N / 200.6m / 111549 94846 ORD 72530 WSFO 1989 1991 87¢X53'W 658.0' 11 Mar 01 Jan 41¢X59'N / 200.6m / 111549 94846 ORD 72530 WSO 1985 1989 87¢X54'W 658.0' 31 Dec 11 Mar 41¢X59'N / 200.6m / 111549 94846 ORD 72530 WSO 1972 1985 87¢X54'W 658.0' 01 Dec 31 Dec 41¢X59'N / 200.6m / 111549 94846 ORD 72530 WBAS WSO 1972 1972 87¢X54'W 658.0' 30 Oct 01 Dec 41¢X59'N / 200.6m / 111549 94846 ORD 72530 WBAS 1958 1972 87¢X54'W 658.0' [Go to Top of Page] Top of Page ------------------------------------------------------------------------ [NOAA Logo] NCDC / Climate-Radar Data Inventories / Locate Station / Search This page dynamically generated 04 Oct 2002 from: http://lwf.ncdc.noaa.gov/oa/climate/stationlocator.html Please send questions or comments about this system to ncdc.webcliserv@noaa.gov Please see the NCDC Contact Page if you have questions or comments.