Local Climatologicat Data Summary Chicago, Illinois

Transcription

1 SWS Miscellaneous Publication STATE OF ILLINOIS DEPARTMENT OF ENERGY AND NATURAL RESOURCES and NATIONAL WEATHER SERVICE, NOAA Local Climatologicat Data Summary Chicago, Illinois by Audrey A. Bryan 1, Herbert Hoffman 2, Wayne Wendland 1, and Paul Dailey 2 1 1llinois State Water Survey, Champaign, IL 2 National Weather Service, Romeoville, IL Illinois State Water Survey 1994

2 CHANGES TO MIDWAY CLIMATOLOGICAL DATA (only changes from those printed are presented here) AVERAGE MAXIMUM TEMPERATURE MIDWAY CHICAGO IL Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann AVERAGE MINIMUM TEMPERATURE MIDWAY CHICAGO IL Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann AVERAGE TEMPERATURE MIDWAY CHICAGO IL Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann COOLING DEGREE DAYS MIDWAY CHICAGO IL Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann HEATING DEGREE DAYS MIDWAY CHICAGO IL Year Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Ann , , , , ,045 TOTAL PRECIPITATION MIDWAY CHICAGO IL Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann SNOWFALL MIDWAY CHICAGO IL Year Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Ann We are indebted to Mr. Frank Wachowski of the National Weather Service Office at Midway Airport for bringing these corrections to our attention.

3 CHICAGO CLIMATOLOGICAL DATA by Audrey A. Bryan 1, Herbert Hoffman 2, Wayne M. Wendland 1 and Paul Dailey2 A cooperative publication of the Illinois State Water Survey 1, Champaign IL and the National Weather Service 2, Romeoville IL.

4 Climatological Summary: LOCAL CLIMATOLOGICAL DATA FOR CHICAGO ILLINOIS Chicago (Cook County) has a temperate continental climate, dominated by maritime tropical air from the Gulf of Mexico from about March through November. Gulf air generally supports relative humidities of about 60% during the day and 85% at night. This is the airmass which yields a "muggy" environment, particularly during June through August. During these months, there are occasional, brief interruptions of drier, cooler air from the Pacific Ocean, but they typically only last a few days. Within a few miles of the Lake Michigan shore, the climate is modified by lake breezes, yielding temperatures 2 to 5 F warmer on winter days than those measured at O'Hare (if lake is not frozen), and cooler by a like amount on summer days. From November through March, the Chicago area is dominated by air from the Pacific Ocean with daily highs in the low 30s and lows in the mid teens. About ten times each winter, cold, dry air from the Canadian Arctic breaks south, bringing temperatures into negative values for a few days, each such outbreak usually preceded by (perhaps heavy) snowfall. Ground frost typically impacts the area from January through March. Snowfalls of 6 inches or more at Chicago are expected about once every other year on average. The greatest snowfall ever during one month in Chicago was 36.4 inches in December Snowcover often continues in Chicago for several weeks at a time. The longest snowcover of at least two inches in Chicago was 111 days during the winter. Summer day temperatures are usually in the 80s, occasionally in the 90s, with nighttime lows about 18 F lower. Humidities are relatively high, and comfort is often impaired. Each summer month generally supports some four inches, of rainfall, mostly in the form of showers and thunderstorms, occasionally accompanied by gusty winds, hail or even a tornado. Summer winds are usually out of the southwest. CHICAGO STATION HISTORY Systematic weather observations from Chicago began in 1830 at Ft. Dearborn. Daily observations are essentially complete since The climate of the Chicago metro area exhibits substantial variations relative to the collar counties due to the influence of the city itself, and Lake Michigan on the local climate.

5 Beginning Date Official Site Location 15 October East Washington St 1 May East Washington St 15 October West Randolph St 8 June January 1887 SE corner Madison and LaSalle St Chicago Opera House, corner Clark and Washington 1 February July 1905 Auditorium Tower Federal Building 1 Jan 1916 University of Chicago 1 Mar 1928 Midway Airport 1 Jan 1958 O'Hare Airport Observations from the last three sites above continue to the present. The following climate averages are presented for each of the three Chicago sites to demonstrate differences in climate within the metro area. Lake Michigan dramatically impacts the metro area. The University of Chicago site lies within 0.2 mile of the lake shore, Midway about 9 miles to the west, and O'Hare about 13 miles to the west. Particularly note the differences in January temperatures, annual snowfall and first fall and last spring frost dates as one proceeds away from the lake. O'HARE MIDWAY UNIV. OF CHICAGO Avg Jan T x Avg Jul T x Annual Precip 35.82" 37.38" 37.22" Annual Snow 38.7" 44.9" 26.9" Winter w/most 83.7" 89.7" 48.9" snow Max 24h precip " ( ) " ( ) " ( ) Max mon precip 17.10" (Aug 87) 14.17" (Sep 61) 11.69" (Oct 54) Absolute T x Absolute T N 104 ( ) -27 ( ) ( ) -25 ( ) 104 ( ) -24 ( ) Last spr frost 24 April 22 Apri 1 12 April 1st fall frost 13 October 25 October 4 November COMMENTS CONCERNING WEATHER RECORDS Earliest weather records in the Midwest generally began in the mid- 1800s. The first official governmental action concerning weather observations was inaugurated under the Surgeon General of the Army in 1814, when all hospital surgeons were asked to keep a weather diary. Systematic observations began under that program in The Smithsonian Institution acquired the meteorological observing program in 1848, under the direction of James P. Espy and Joseph Henry. For the first time in the U.S., observers were provided with instruments. By 1850, 301 sites were taking routine weather observations in the country. An additional 200 were added within the next decade. In 1870, military posts were directed to regularly observe the weather, and the U.S. Weather Bureau (forerunner of the National Weather Service), became a new agency of the U.S. Signal Service in 1871 and began managing the network. In 1873, all meteorological work was directed solely

6 by the Signal Service. In 1891 the U.S. Weather Bureau was transferred to the U.S. Dept. of Agriculture, and in 1940, again, transferred to the Dept. of Commerce, its present home. Today, daily observations of temperature and precipitation are available from about 200 sites in Illinois. Atlantic storm warnings were first made in 1885, followed by cold wave warnings with 3 days lead the following year. Twenty-four hour hurricane observing and warning service began in Five-day forecasts were first issued in 1940, 30- and 90-day outlooks began in the 1950s, and outlooks for the coming year in January Temperature and precipitation records are not likely homogeneous over long periods of record. For example, raingages with small catchments were preferred during the early/mid-1800s. Today, the standard raingage has a diameter of 8 inches, exhibiting a different catchment efficiency. Daily mean temperatures are currently based on the average of the daily maximum and minimum. Maximum/minimum thermometers were not commonly available until the late 1800s, therefore prior to that time daily mean temperatures were defined as either (1) the average of the 0700, 1400 and 2100 observations (suggested by the Mannheim Meteorological Society), or the average of the 0700, 1400, and twice the 2100 temperatures, the latter more closely approximating the average of all 24 hourly readings of a day (Schott, 1876). The Chicago weather stations are three of about 200 such observing sites in Illinois under the direction of the National Weather Service. Climatological data and information for these locations are available from either: Illinois State Water Survey National Climatic Data Center ATTN: STATE CLIMATOLOGIST Federal Building 2204 Griffith Dr. Asheville NC Champaign IL The Illinois State Water Survey has prepared climatological summaries similar to this for the following locations: Aurora Fairfield Lincoln Peoria Champaign Freeport Moline Springfield Decatur Harrisburg Ottawa White Hall Cox, H-J. & J.H. Armington, 1914: The weather and climate of Chicago. University of Chicago Press, Chicago. 375 p. Page, J.L., 1949: Climate of Illinois. Bulletin 532. Univ. of Illinois Agr. Experiment Station. Urbana. 364 p. Schott, C.A., 1876: Tables, distribution, and variations of the atmospheric temperature in the U.S. Smithsonian Contributions to Knowledge #277. Smithsonian Inst. Washington. 345 p.

7 Probabilities: Precipitation (in) Missing Data: 0.2% Station: (111549) CHICAGO_0'HARE_WSO_ARPT Years: 1961 To % 5% 10% 25% 50% 75% 90% 95% 99% Ja Fe Ma Ap Ma Jn Ju Au Se Oc No De An wi Sp Su Fa Growing Season Summary Station: (111549) CHICAGO_0'HARE_WSO_ARPT Years: 1961 To 1990 Missing Data: 0% Base Date of : Last Spring Occurrence Date of First Fall Occurrence Temp Median Early 90% 10% Late Median Early 10% 90% Late 32 4/30 4/09 4/10 5/11 5/29 10/11 9/22 9/30 10/26 11/ /11 3/31 4/04 4/24 5/09 10/25 9/23 10/07 11/15 11/ /05 3/18 3/22 4/18 5/10 11/07 10/08 10/24 11/20 11/ /23 2/22 3/13 4/07 4/10 11/20 10/11 10/30 12/03 12/ /16 2/07 2/18 4/02 4/09 12/01 11/09 11/16 12/09 12/10 Base Length of Season (Days) Temp Median Shortest 10% 90% Longest

8 AVERAGE MAXIMUM TEMPERATURE O'HARE CHICAGO, IL YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT MOV DEC AVERAGE

9 AVERAGE MINIMUM TEMPERATURE O'HARE CHICAGO, IL Year JAN FEB HAS APR MAY JUM JUL AUG SEP OCT NOV DEC AVERAGE ' ,

10 AVERAGE TEMPERATURE O'HARE CHICAGO, IL YEAR JAN FEB MAR APR HAY JUN JUL AUG SEP OCT NOV DEC AVERAGE

11 COOLING DEGREE DAYS O'HARE CHICAGO, IL YEAR JAN FEB HAR APR HAY JUN JUL AUG SEP OCT NOV DEC TOTAL , , , , , , , ,

12 HEATING DEGREE DAYS O'HARE CHICAGO, IL SEASONAL YEAR JUL AUG SEP OCT NOV DEC JAN FEB HAS APR HAY JUN TOTAL ,375 1,509 1, ,175 1,164 1, , ,282 1, , ,223 1,489 1, , ,291 1,655 1, , ,599 1,149 1, , ,240 1,342 1,134 1, , ,502 1, , ,170 1,148 1, , ,068 1,274 1, , ,146 1, , ,138 1,506 1, , ,055 1,422 1, , ,405 1, , ,269 1,135 1, , ,139 1,240 1, , ,072 1,160 1, , ,033 1, , ,408 1,679 1, , ,254 1,521 1,346 1, , ,206 1,622 1, , ,281 1, , ,140 1,308 1, , ,236 1,632 1, , , , ,568 1, , , ,046 1,563 1, , ,480 1,302 1, , ,060 1, , ,011 1,396 1, , ,149 1,003 1, , , , ,120 1, , ,066 1, , ,122 1,196 1, , ,047

13 TOTAL PRECIPITATION O'HARE CHICAGO, IL YEAR JAN FEB MAS APR MAY JON JUL AUG SEP OCT NOV DEC TOTAL '

14 SNOWFALL O'HARE CHICAGO, IL YEAR JUL AUG SEP OCT NOV DEC JAN FEB HAR APR HAY JUN SEASONAL TOTAL Monthly totals of a Trace, an amount too small to be measured, were not reported.

15 Probabilities: Precipitation (in) Missing Data: 1% Station: (111577) CHICAG0_MIDWAY_AP_3_SW Years: 1961 To % 5% 10% 25% 50% 75% 90% 95% 99% Ja Fe Ma Ap Ma Jn Ju AU Se OC NO De An wi Sp Su Fa Growing Season Summary Station: (111577) CHICAGO_MIDWAY_AP_3_SW Years: 1961 To 1990 Missing Data: 0.8% Base Date of Last Spring Occurrence Date of First Fall Occurrence Temp Median Early 90% 10% Late Median Early 10% 90% Late 32 4/19 4/03 4/08 5/10 5/16 10/26 10/01 10/07 11/10 11/ /07 3/18 3/23 4/18 5/12 11/05 10/02 10/21 11/15 11/ /25 3/14 3/17 4/09 4/18 11/14 10/24 11/01 12/01 12/ /19 2/03 2/25 4/06 4/09 11/28 10/24 11/09 12/08 12/ /06 1/27 2/11 4/02 4/07 12/03 11/12 11/19 12/20 12/27 Base Length of Season (Days) Temp Median Shortest 10% 90% Longest

16 AVERAGE HAXIHUH TEHPERATORE HIDWAY CHICAGO, IL YEAR JAN FEB HAS APR HAY JUN JUL AUG SEP OCT NOV DEC AVERAGE M M @ M M * O'Hare data substituted, Hidvay data missing ** Annual average calculated from O'Hare and Hidvay data 8 Mean monthly maximum temperature data no longer available H Honthly- fever than 4 days missing. Annually- one or more months are incomplete.

17 AVERAGE MAXIMUM TEMPERATURE MIDWAY CHICAGO, IL YEAR JAN FEB HAS APR MAY JUN JUL AUG SEP OCT NOV DEC AVERAGE * 56.4* 71.9* M 83.8M **M * O'Hare data substituted, Midway data missing ** Annual average calculated from O'Hare and Midway Mean monthly maximum temperature data no longer available H Monthly- fewer than 4 days missing. Annually- one or more months are incomplete.

18 AVERAGE MINIMUM TEMPERATURE MIDWAY CHICAGO, IL YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVERAGE M M M M M M * O'Hare data substituted, Midvay data missing ** Annual average calculated fron O'Hare and Hidvay data 8 Mean Monthly minimum temperature no longer available M Monthly- fewer than 4 days missing. Annually- one or more months are incomplete

19 AVERAGE MINIHUM TEMPERATURE MIDWAY CHICAGO, IL YEAR JAN FEB MAR APR HAY JUN JUL AUG SEP OCT NOV DEC AVERAGE * 36.6* 47.5* M 64.6M **H * O'Hare data substituted, Midway data missing ** Annual average calculated from O'Hare and Midway Mean monthly minimum temperature no longer available M Monthly- fewer than 4 days missing. Annually- one or more months are incomplete

20 AVESAGE TEHPEKATDSE MIDWAY CHICAGO, IL YEAS JAN FEB HAS APS HAY JON JUL AUG SEP OCT NOV DEC AVERAGE * O'Hare data substituted, Midway data missing ** Annual average calculated from O'Hare and Midway data M Monthly- fever than 4 days nissing. Annually- one or more months are incomplete

21 AVERAGE TEHPERATDRE MIDWAY CHICAGO, IL YEAR JAN FEB HAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVERAGE * 46.5* 59.7* M 74.2M **M * O'Etare data substituted, Midway data missing ** Annual average calculated from O'Hare and Midway data M Monthly- fewer than 4 days missing. Annually- one or more months are incomplete

22 COOLING DEGREE DAYS HIDWAY CHICAGO, IL YEAR JAN FEB HAS APR HAY JUN JUL AUG SEP OCT NOV DEC TOTAL # 205# 24# 0# 0 0# # # 267# 174# 78# 0# ## # # 248# 118# 0# ## # # 353# 233# 180# # 1,036## # 242# 65# 0# ## # 185# 168# 0# 3 0# 1,125## # 0 0 0# # 223# 78# 0# 0 0 1,101## # 260# 110# 0# ## # 347# 138# 0# 0 0 1,165## # 357# 84# 0# 0 0# 950## # # 335# 105# 0# ## * # 239# 167# 0# 0 0 1,073## # # 251# 91# 0# ## # 279# 157# 0# 0# 0 1,066## # # # 229# 59# 0# ## # # 310# 46# 0# ## # 282# 119# 0# 4 0 1,093## # 217# 84# 0# ## # 0# # 181# 110# 0# 0 0# 802## # 471# 127# 52# ## # # 887## , # 0# ## # ## , # 0 0 0# # 353# 335# 141# # 1,212## # # ,240## # 0# 6 80# ,354## # # # 1,034## # 0# # ## ,308## ,040 # Degree days based on mean monthly temperature as opposed to daily accumulated values ## Annual total calculated from values based on mean monthly temperature and daily accumulated values * O'Hare data substituted, Hidvay data missing ** Annual total calculated from O'Hare and Hidvay data # Annual total calculated from daily accumulated values, values based on mean monthly temperature, O'Hare and Hidvay data H Honthly- fever than 4 days missing. Annually- one or more months are incomplete

23 COOLING DEGREE DAYS MIDWAY CHICAGO, IL YEAR JAN FEB KM APR HAY JUN JUL AUG SEP OCT NOV DEC TOTAL , , , , , , , , , , , * 0* 10* 43* H 297H # 0 936/M , , , , , , # Degree days based on mean monthly temperature as opposed to daily accumulated values ## Annual total calculated from values based on mean monthly temperature and daily accumulated values * O'Hare data substituted, Hidvay data missing ** Annual total calculated from O'Hare and Hidvay data / Annual total calculated from daily accumulated values, values based on mean monthly temperature, O'Hare and Hidvay data M Honthly- fever than 4 days missing. Annually- one or more months are incomplete

24 HEATING DEGREE DAYS MIDWAY CHICAGO, IL SEASONAL YEAS JDL AUG SEP OCT NOV DEC JAN FEB HAS APR HAY JUN TOTAL # 0# 176# 326# 726 1,073# 1,535 1, # # 6,688## # 26# 122# 440# 915 1,181 1, # ,604## # 0# 83# 450# 723 1,149 1, # 324 0# 6,065## # 0# 21# # 1, , ,438## # 0# 135# 422# 893 1, , ,319## # 15# 32# 434# 841 1,097# 1,048# 1,218 1, # ,339## # 0# 122# 298# 613 1,256 1,263 1, ,280## # 0# 91# 366# 791 1,266 1,463 1, ,060## # 0# 62# 391# ,212 1, ,382## # 0# 116# 456# 867 1,218# 1, # ,110## # 0# 95# 236# 676 1,141 1,073# 1, ,887## # 0# 33f 313# ,533 1,050# 1, ,499## # 0# 110# 248# ,164 1,129 1, ,970## # 0# 43# 291# 690# 925 1,262# 1, # 37 5,688## # 0# 141# 363# 714 1,296 1,304 1,042# 1, ,774## # 0# 154# 350# 854 1,151 1,037 1,040 1, ,345## # 0# 81# 360# 666 1,304 1,410 1, ,233## # 0# 116f 422# 750 1,323 1,179 1, # 417# ,119## # 20# 91# 207# 674 1,026# 1,119 1,239 1, ,375## # 0# 73# 148# 903 1,078 1,448 1, ,387## # ,076# 1,128 1, ,895## ,025 1,095 1, # 705# ,281## ,403 1,283 1, , ,196 1, , ,005 1, , ,022 1, , ,020 1,238 1, , ,205 1,123 1, , , , ,192 1, , ,315 1,437 1, , ,137 1,132 1, ,400 # Degree days based on mean monthly temperature as opposed to daily accumulated values ## Seasonal total calculated from values based on mean monthly temperature and daily accumulated values * O'Hare data substituted, midvay data missing ** Seasonal total calculated from O'Hare and Hidvay data H Monthly- fewer than 4 days missing. Seasonal Total- one or more months are incomplete

25 HEATING DEGREE DAYS MIDWAY CHICAGO, IL SEASONAL YEAR JUL AOG SEP OCT NOV DEC JAN FEB MAR APR HAY JUN TOTAL ,225 1, , ,204 1,450 1, , ,234 1,600 1, , ,454 1,090 1, , ,160 1,250 1,048 1, , ,437 1, , ,116 1,113 1, , ,027 1,243 1, , ,116 1, , ,118 1,475 1, , ,032 1,413 1, , ,311 1, , ,224 1, , ,158 1,230 1, , ,041 1,144 1, , ,029 1, , ,388 1,695 1, , ,242 1,517 1,346 1, , ,199 1,628 1, , ,274 1,254* 995* 558* 198* 55 6,454** Om 3M * 1,134 1,277 1, ,186i##M ,176 1,567 1, , , , ,499 1, , , ,466 1, , ,402 1,200 1, , ,051 1, , ,358 1, , , , , , , ,051 1, , , , ,050 1,141 1, , ,065 # Degree days based on mean monthly temperature as opposed to daily accumulated values ## Seasonal total calculated from values based on mean monthly temperature and daily accumulated values * O'Hare data substituted, Hidway data missing ** Seasonal total calculated from O'Hare and Hidvay data M Honthly- fewer than 4 days missing. Seasonal Total- one or more months are incomplete

26 TOTAL PRECIPITATION MIDWAY CHICAGO, IL YEAS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL , * O'Hare data substituted, Midvay data missing ** Annual total calculated from O'Hare and Kidvay data

27 TOTAL PRECIPITATION MIDWAY CHICAGO, IL YEAR JAN FEB HAS APR KAY JUN JUL AD6 SEP OCT NOV DEC TOTAL , * 1.24* 1.96* 3.41* 3.22* ** , * O'Hare data substituted, Midway data nissing ** Annual total calculated from O'Hare and Hidvay data

28 SNOWFALL MIDWAY CHICAGO, IL SEASONAL YEAS JUL AUG SEP OCT NOV DEC JAN FEB NAB APR HAY JON TOTAL * O'Hare data substituted, Midway data lissing ** Seasonal total calculated from O'Hare and Hidvay data Monthly totals 0# a Trace, an aroint too snail to be measured, vere not reported.

29 SNOWFALL MIDWAY CHICAGO, IL SEASONAL YEAS JUL AUG SEP OCT NOV DEC JAN FEB MAR APS HAY JOH TOTAL , * * 44.3** * O'Hare data substituted, Midway data missing ** Seasonal total calculated from O'Hare and Hidvay data Monthly totals 0# a Trace, an amount too smail to be measured, were not reported.

30 Probabilities: Precipitation (in) Missing Data: 0.9% Station: (111572) CHICAGO_UNIVERSITY Years: 1961 To % 5% 10% 25% 50% 75% 90% 95% 99% Ja Fe Ma Ap Ma Jn Ju Au Se Oc No De An Wi Sp Su Fa Growing Season Summary Station: (111572) CHICAGO_UNIVERSITY Years: To 1990 Missing Data: 0.9% Base Date o: f Last Spring Occurrence Date of First Fall Occurrence Temp Median Early 90% 10% Late Median Early 10% 90% Late 32 4/10 3/25 4/02 4/24 4/25 11/04 10/11 10/23 11/14 11/ /03 3/16 3/19 4/11 4/18 11/12 10/23 10/28 11/27 12/ /25 3/14 2/23 2/03 3/04 2/21 4/07 3/31 4/10 4/07 11/24 10/24 12/01 11/06 11/06 12/07 12/09 11/14 12/10 12/ /02 1/27 2/08 3/29 4/07 12/10 11/13 11/22 12/22 12/31 Base Length of Season (Days) Temp Median Shortest 10% 90% Longest