[NOAA] 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 * Online Data List Stations in Division IL-02 * Station History List Stations in Cook County * State Climatologist Surrounding Stations (+/- 30' Lat/Lon) * Regional Climate Center Type* : ASOS-NWS FCWOS ----------------------------- Call Information at Other Sites Sign/ICS* : ORD / KORD * National Weather Service - Central Region Headquarters WBAN* : 94846 - Regional Forecast Office COOP ID* : 111549 - Current Weather Conditions Climate Division* : IL-02 - Northeast - Current Weather Forecast WMO ID* : 72530 * Current Radar * Current Satellite In Service* : 30 Oct 1958 to Present * Sunrise/Sunset Elevation*: 200.6m (658.0') above sea level Lat/Lon* : 41¢X59'N / 87¢X55'W County*: Cook * Disclaimer * List of NCDC Datasets * Please report any Data Errors found. * Note to webmasters: you can link directly to this page. ------------------------------------------------------------------------ [Image] Other Stations in Chicago Chicago Chicago / Aurora Municipal Airport 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 ------------------------------------------------------------------------ [Image] 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: DAT to obtain data (charges may apply), INV to view inventory, or 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 -DATSAV2 Surface, Global Surface Hourly Data (see Global Surface Station Information). ------------------------------------------------------------------------ [Image] Online Data NNDC Climate Data Online (CDO) IMPORTANT NOTE: Data from the CDO is not described as it is in some of our products. CDO data comes in flat ASCII files (see sample and documentation) and is provided as input into spreadsheets and other applications. There is a charge for this data. If you don't know what a flat ASCII file is, you probably don't want to use the CDO System to get your data. SOD -Daily Surface Data (TD3200/3210 combined) 3220 -Summary Of The Month (SOM) Cooperative 3240 -Hourly Precipitation Data Daily Data, Summary of the Day Observations (NWS Cooperative Stations) Hourly/Daily Data, Local Climatological Data Hourly Data, Form 10A/10B Graph Weather Elements The graphs generated here are from the National Weather Service Summary of the Day dataset. For additional data and visualization, use CLIMVIS. Select the desired values for Element 1, Element 2 and Month. Enter the desired Year and Submit Graph Values to view graph. Element 1 Element 2 Year/Month ------------------------------------------------------------------------ [Image] 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¢X 658.0' FCWOS 55'W 01 Feb 20 Aug 41¢X59'N 200.6m / 111549 94846 ORD 72530 ASOS-NWS 1996 1997 / 87¢X 658.0' WSCMO 55'W 01 Apr 01 Feb 42¢X00'N 200.6m / 111549 94846 ORD 72530 WSCMO 1995 1996 / 87¢X 658.0' 53'W 01 Jan 01 Apr 42¢X00'N 200.6m / 111549 94846 ORD 72530 WSO 1995 1995 / 87¢X 658.0' 53'W 03 Dec 01 Jan 42¢X00'N 200.6m / 111549 94846 ORD 72530 WSO 1991 1995 / 87¢X 658.0' 53'W 19 Jan 03 Dec 42¢X00'N 200.6m / 111549 94846 ORD 72530 WSFO 1989 1991 / 87¢X 658.0' 53'W 11 Mar 01 Jan 41¢X59'N 200.6m / 111549 94846 ORD 72530 WSO 1985 1989 / 87¢X 658.0' 54'W 31 Dec 11 Mar 41¢X59'N 200.6m / 111549 94846 ORD 72530 WSO 1972 1985 / 87¢X 658.0' 54'W 01 Dec 31 Dec 41¢X59'N 200.6m / 111549 94846 ORD 72530 WBAS WSO 1972 1972 / 87¢X 658.0' 54'W 30 Oct 01 Dec 41¢X59'N 200.6m / 111549 94846 ORD 72530 WBAS 1958 1972 / 87¢X 658.0' 54'W [Image] Top of Page ------------------------------------------------------------------------ [NOAA] NCDC / Climate-Radar Data Inventories / Locate Station / Search This page dynamically generated 26 May 2000 from: http://www.ncdc.noaa.gov/ol/climate/stationlocator.html Please send questions or comments about this system to webcliserv@ncdc.noaa.gov Please see the NCDC Contact Page if you have questions or comments.