Historical Record High Temperatures

With the recent warm weather, have you wondered what the record high temperatures are for Chicago and elsewhere? In the last few years, a group composed of NWS, Regional Climate Centers, and State Climatologists stitched together the weather records for 270 major metropolitan areas. The results of this project can be found at http://threadex.rcc-acis.org/
The sites in Illinois include Chicago, Moline, Peoria, Rockford, and Springfield. Amongst other things, the program reports the daily record high and low temperature and precipitation.
Here I selected the record highs for Chicago and pulled out the results for September. The program gives you the top three candidates and their dates.

Threaded Climate Extremes for Chicago Area, IL
Period of record: 1872 - 2009
Date	Highest Maximum Temperatures (degrees F)
Top 	Record		2nd Record	3rd Record
9/1	101 in 1953	96 in 1984	95 in 1960+
9/2	101 in 1953	98 in 1922	97 in 1913
9/3	97 in 1953	95 in 1960	95 in 1947
9/4	95 in 1983	95 in 1960	95 in 1954
9/5	98 in 1899	97 in 1954	95 in 1983+
9/6	97 in 1960	97 in 1954	96 in 1990+
9/7	100 in 1960	100 in 1939	99 in 1985
9/8	96 in 1960	96 in 1959	96 in 1933+
9/9	95 in 1983	95 in 1959	95 in 1955
9/10	95 in 1983	94 in 1964	94 in 1931+
9/11	95 in 1952	92 in 1908	92 in 1895
9/12	96 in 1952	94 in 1939	93 in 1962
9/13	98 in 1939	95 in 1927	94 in 2005+
9/14	99 in 1939	95 in 1927	95 in 1893
9/15	99 in 1939	94 in 1927	92 in 1955
9/16	92 in 1955	92 in 1931	89 in 1948+
9/17	93 in 1955	90 in 1988	90 in 1891
9/18	94 in 1955	92 in 1953	90 in 1963+
9/19	93 in 1955	92 in 1963	92 in 1948
9/20	91 in 1931	91 in 1895	90 in 1980+
9/21	92 in 1970	90 in 1931	90 in 1924+
9/22	92 in 1956	90 in 1986	90 in 1959+
9/23	91 in 1937	88 in 1892	87 in 1945+
9/24	91 in 1891	90 in 2007	90 in 1920
9/25	90 in 1933	89 in 1920	89 in 1900
9/26	90 in 1998	87 in 1973	86 in 1999+
9/27	91 in 1971	89 in 1987	89 in 1954
9/28	92 in 1953	90 in 1952	89 in 1971
9/29	99 in 1953	87 in 1921	87 in 1898
9/30	92 in 1971	88 in 1943	87 in 1952
+ indicates same value also occurred in a previous year.

Record Streak of Warm Days in Chicago

From the National Weather Service

Record of Days At or Above 80 Degrees for Chicagoland

THE PREVIOUS RECORD FOR CONSECUTIVE 80 DEGREE OR ABOVE DAYS WAS 42
DAYS IN A ROW...SET IN 1955. ON AUGUST 13 2010...THE CHICAGOLAND
AREA HIT 43 CONSECUTIVE DAYS...AND THE NUMBER CONTINUES TO
INCREASE. JULY 2 2010 WAS THE FIRST 80 DEGREE DAY OF THE CURRENT
RECORD. AS OF 251 PM CDT TODAY...WHEN THE TEMPERATURE AT OHARE
INTERNATIONAL AIRPORT OFFICIALLY REACHED 80 DEGREES DURING
AFTERNOON HEATING...TODAY IS THE 46 CONSECUTIVE DAY FOR THIS
RECORD.
THE TOP TEN RECORDS ARE AS FOLLOWS
1.   46 DAYS...WITH THE STREAK STILL CONTINUING ON AUGUST 16 2010
2.   42 DAYS...WITH THE STREAK ENDING ON AUGUST 7 1955
3.   34 DAYS...WITH THE STREAK ENDING ON SEPTEMBER 6 1995
4.   32 DAYS...WITH THE STREAK ENDING ON AUGUST 8 1983
5.   30 DAYS...WITH THE STREAK ENDING ON JULY 19 1921
6.   29 DAYS...WITH THE STREAK ENDING ON AUGUST 18 1988
7.   27 DAYS...WITH THE STREAK ENDING ON AUGUST 6 1999
8.   27 DAYS...WITH THE STREAK ENDING ON JULY 14 1966
9.   25 DAYS...WITH THE STREAK ENDING ON AUGUST 15 2007
10. 24 DAYS...WITH THE STREAK ENDING ON JULY 26 2005

July 1936 – Hot in Chicago

While this summer has been hot and humid, it pales in comparison to the hottest month in Illinois history – July 1936. Here are the records from July of that year at Midway Airport in Chicago. The temperature hit the triple digit mark nine times that month.  That’s more times than for the entire 1954 to present-day period at Midway Airport. Also, eight of those nine days in July were consecutive.
It was also very dry with only 0.31 inches of precipitation that month. A “T” in the precipitation column means the a trace event – enough to wet the sidewalk but not enough to measure.
The second table has the reports from the University of Chicago site. Those numbers show that conditions closer to the lake were a little more tolerable that summer but still very warm. And this was all before air conditioning was in widespread use.

(111577) CHICAGO MIDWAY AP_IL
Date Precip
(in)
MaxT
(F)
MinT
(F)
1936-07-01 0.00 86 55
1936-07-02 0.00 79 63
1936-07-03 0.00 86 60
1936-07-04 T 91 64
1936-07-05 T 82 68
1936-07-06 0.00 92 68
1936-07-07 0.00 102 70
1936-07-08 0.00 106 73
1936-07-09 0.06 100 71
1936-07-10 0.00 106 77
1936-07-11 T 107 76
1936-07-12 0.00 100 76
1936-07-13 0.00 102 73
1936-07-14 0.00 104 69
1936-07-15 0.00 91 74
1936-07-16 0.00 91 72
1936-07-17 0.00 93 66
1936-07-18 0.14 86 70
1936-07-19 0.05 80 62
1936-07-20 0.00 80 57
1936-07-21 0.00 88 60
1936-07-22 0.00 95 59
1936-07-23 0.06 99 69
1936-07-24 T 78 66
1936-07-25 T 94 64
1936-07-26 T 102 71
1936-07-27 T 85 67
1936-07-28 0.00 98 60
1936-07-29 0.00 74 65
1936-07-30 0.00 78 51
1936-07-31 0.00 83 50
Sum: 0.31 2838 2046
Count: 31 31 31
Average: 0.01 91.5 66.0
M = Missing, T = trace
(111572) UNIVERSITY OF CHICAGO
Date Precip
(in)
MaxT
(F)
MinT
(F)
1936-07-01 0.00 82 58
1936-07-02 0.00 72 63
1936-07-03 T 81 61
1936-07-04 T 82 64
1936-07-05 0.01 74 66
1936-07-06 0.00 84 67
1936-07-07 0.00 95 72
1936-07-08 0.00 95 76
1936-07-09 0.03 95 74
1936-07-10 0.00 102 80
1936-07-11 0.00 97 80
1936-07-12 0.00 89 76
1936-07-13 0.00 91 76
1936-07-14 0.00 96 75
1936-07-15 0.00 86 74
1936-07-16 0.00 82 73
1936-07-17 0.00 84 70
1936-07-18 0.10 81 71
1936-07-19 T 75 70
1936-07-20 0.00 76 67
1936-07-21 0.00 79 66
1936-07-22 0.00 89 66
1936-07-23 0.05 95 70
1936-07-24 T 72 68
1936-07-25 0.00 83 66
1936-07-26 T 90 71
1936-07-27 0.03 86 68
1936-07-28 0.00 87 65
1936-07-29 0.00 73 65
1936-07-30 0.00 74 64
1936-07-31 0.00 78 58
Sum: 0.22 2625 2140
Count: 31 31 31
Average: 0.01 84.7 69.0
M = Missing, T = trace

Rainfall Totals for July in the Chicago Area

Here are some rainfall totals for July 2010 [updated on August 3] for the Chicago area. This is preliminary and may contain missing or incorrect data. Missing data can make the monthly totals too low.  Based on what has been reported so far, Midway Airport has set a new record for July precipitation, beating the old record of 8.98 inches set in 1957.

Monthly Data for July 2010 for Illinois – Northeast Climate Division
Station Total Precipitation
BARRINGTON 3 SW 7.18
BELVIDERE 7.24
CHICAGO BOTANICAL GARDEN 5.51
CHICAGO MIDWAY AP 10.39
CHICAGO MIDWAY AP 3 SW 9.17
CHICAGO OHARE INTL AP 8.84
DE KALB 6.92
EARLVILLE 3 S 3.31
ELBURN 6.28
ELGIN 7.68
GENOA 2 SW 8.89
GLEN ELLYN 4 S 7.48
HARVARD 9.52
JOLIET BRANDON RD DM 5.00
MARENGO 6.53
MARSEILLES LOCK 3.87
MCHENRY STRATTON L 3.28
MENDOTA 2 SE 3.29
MONEE RSVR 6.01
MORRIS 3.89
MUNDELEIN 4 WSW 7.06
NEWARK 2 SSE 3.91
OAK BROOK 2W 9.02
PARK FOREST 6.38
PERU 2.74
PLAINFIELD 3 NE 7.48
ROMEOVILLE LEWIS UNIV AP 8.05
SHABBONA 3S 5.29
SPRING GROVE 6.89
ST CHARLES 7 NW 9.44
STREAMWOOD 6.91
WHEATON 3 SE 6.25
WOODSTOCK 5 NW 6.65
YORKVILLE 3 SW 4.31