Record envelope, standing records and threshold days for Cahokia (USC00111160), Illinois, United States, with 44 years of record.
Key Facts for Cahokia
Cahokia (USC00111160) is a weather station in Illinois, United States at 38.57 latitude and -90.19 longitude, 122 m (400 ft) above sea level.
The station reports from 1969 to 2012, 44 years of record.
1,464 records set at Cahokia still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Cahokia tied a daily record high minimum temperature of 20.6 C (69.1 F) on 29 May 2012.
About the Station
Location: Illinois, United States, 38.57 latitude, -90.19 longitude.
Elevation: 122 m (400 ft).
Period of record: 1969 to 2012, 44 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Cahokia. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Cahokia, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.6 C (78.1 F)
-28.3 C (-18.9 F)
n/a
n/a
Feb
27.2 C (81.0 F)
-25.0 C (-13.0 F)
n/a
n/a
Mar
31.7 C (89.1 F)
-21.7 C (-7.1 F)
n/a
n/a
Apr
33.9 C (93.0 F)
-7.8 C (18.0 F)
n/a
n/a
May
34.4 C (93.9 F)
0.0 C (32.0 F)
n/a
n/a
Jun
39.4 C (102.9 F)
5.0 C (41.0 F)
n/a
n/a
Jul
41.1 C (106.0 F)
6.7 C (44.1 F)
n/a
n/a
Aug
40.6 C (105.1 F)
5.0 C (41.0 F)
n/a
n/a
Sep
39.4 C (102.9 F)
0.0 C (32.0 F)
n/a
n/a
Oct
34.4 C (93.9 F)
-5.6 C (21.9 F)
n/a
n/a
Nov
29.4 C (84.9 F)
-16.1 C (3.0 F)
n/a
n/a
Dec
26.1 C (79.0 F)
-28.3 C (-18.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Cahokia still stand. 1988 holds the most, with 63.
Standing records at Cahokia by the year they were set
Year set
Standing records
1969
14
1970
41
1971
54
1972
55
1973
16
1974
47
1975
31
1976
56
1977
45
1978
47
1979
33
1980
39
1981
18
1982
36
1983
10
1984
12
1985
37
1986
43
1987
39
1988
63
1989
53
1990
53
1991
53
1992
23
1993
33
1994
21
1995
24
1996
32
1997
30
1998
39
1999
19
2000
48
2001
27
2002
22
2004
25
2005
29
2006
31
2007
35
2008
30
2009
28
2010
20
2011
30
2012
23
Wettest Day of Each Month
May: 111.0 mm (4.4 in)
The wettest day on record for each calendar month at Cahokia. The most was 111.0 mm (4.4 in) on 16 May 1990.
Record daily precipitation for each month at Cahokia
Month
Record daily precipitation (mm)
Date
Jan
60.7 mm (2.4 in)
3 January 2005
Feb
62.7 mm (2.5 in)
7 February 1999
Mar
78.7 mm (3.1 in)
28 March 1977
Apr
76.2 mm (3.0 in)
28 April 1994
May
111.0 mm (4.4 in)
16 May 1990
Jun
68.1 mm (2.7 in)
12 June 2002
Jul
88.1 mm (3.5 in)
10 July 1991
Aug
108.5 mm (4.3 in)
18 August 1998
Sep
80.0 mm (3.1 in)
23 September 1993
Oct
64.0 mm (2.5 in)
30 October 2009
Nov
58.9 mm (2.3 in)
25 November 2010
Dec
83.8 mm (3.3 in)
10 December 1971
Period of Record Coverage
1969 to 2012
Complete yearUnder 90 percent of days
43 years of record at Cahokia, 1969 to 2012. 13 years have data for under 90 percent of days and are left out of rankings: 1969, 1970, 1973, 1980, 1981, 1982, 1983, 1984 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 27 complete years at Cahokia, 1972 to 2010. Blue stripes are years cooler than the station's own mean of 13.3 C (55.9 F); red stripes are warmer. The coolest year was 1972, at 11.9 C (53.4 F), and the warmest was 1998, at 14.4 C (58.0 F). The strongest colour marks a difference of 1.4 C (2.5 F).
Annual mean temperature at Cahokia as warming stripes, 1972 to 2010
Year
Annual mean temperature
Difference from the station mean
1972
11.9 C
-1.34 C
1974
12.6 C
-0.61 C
1975
12.9 C
-0.39 C
1976
12.1 C
-1.12 C
1977
12.4 C
-0.87 C
1985
12.5 C
-0.76 C
1986
14.0 C
+0.76 C
1987
13.9 C
+0.68 C
1988
13.0 C
-0.30 C
1989
12.4 C
-0.87 C
1990
14.3 C
+1.08 C
1991
14.3 C
+1.04 C
1992
13.8 C
+0.55 C
1993
12.9 C
-0.33 C
1994
13.7 C
+0.40 C
1995
13.5 C
+0.26 C
1996
12.5 C
-0.79 C
1998
14.4 C
+1.18 C
1999
13.9 C
+0.60 C
2000
12.9 C
-0.32 C
2001
13.5 C
+0.24 C
2005
13.8 C
+0.59 C
2006
14.1 C
+0.80 C
2007
14.0 C
+0.74 C
2008
12.4 C
-0.86 C
2009
12.6 C
-0.61 C
2010
13.5 C
+0.26 C
This station does not have enough complete years (30 are needed) to fit a temperature trend.
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1969 to 2012
Yearly extremes at Cahokia: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.1 C (106.0 F)
1980
36.7 C (98.1 F)
43
Coldest night (TNn)
-28.3 C (-18.9 F)
1977
-18.3 C (-0.9 F)
43
Wettest day (Rx1day)
111.0 mm (4.4 in)
1990
60.7 mm (2.4 in)
43
Wettest five days (Rx5day)
182.6 mm (7.2 in)
1995
99.8 mm (3.9 in)
43
Longest dry spell (CDD)
42 days
1979
20 days
43
Hottest day (TXx)
The hottest day of the year at Cahokia, 1969 to 2012. The record is 41.1 C (106.0 F) in 1980, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Cahokia by year
Year
Hottest day (TXx)
1969
35.0 C (95.0 F)
1970
40.0 C (104.0 F)
1971
38.9 C (102.0 F)
1972
36.7 C (98.1 F)
1973
35.6 C (96.1 F)
1974
37.2 C (99.0 F)
1975
37.2 C (99.0 F)
1976
38.9 C (102.0 F)
1977
36.7 C (98.1 F)
1978
39.4 C (102.9 F)
1979
36.1 C (97.0 F)
1980
41.1 C (106.0 F)
1981
35.0 C (95.0 F)
1982
32.8 C (91.0 F)
1983
27.8 C (82.0 F)
1984
38.3 C (100.9 F)
1985
36.1 C (97.0 F)
1986
39.4 C (102.9 F)
1987
38.9 C (102.0 F)
1988
38.9 C (102.0 F)
1989
36.1 C (97.0 F)
1990
38.9 C (102.0 F)
1991
37.8 C (100.0 F)
1992
35.0 C (95.0 F)
1993
35.0 C (95.0 F)
1994
35.6 C (96.1 F)
1995
37.8 C (100.0 F)
1996
35.0 C (95.0 F)
1997
36.7 C (98.1 F)
1998
36.7 C (98.1 F)
1999
39.4 C (102.9 F)
2000
37.8 C (100.0 F)
2001
36.7 C (98.1 F)
2002
35.6 C (96.1 F)
2004
36.7 C (98.1 F)
2005
37.8 C (100.0 F)
2006
37.8 C (100.0 F)
2007
40.6 C (105.1 F)
2008
36.1 C (97.0 F)
2009
35.0 C (95.0 F)
2010
38.9 C (102.0 F)
2011
39.4 C (102.9 F)
2012
34.4 C (93.9 F)
Coldest night (TNn)
The coldest night of the year at Cahokia, 1969 to 2012. The record is -28.3 C (-18.9 F) in 1977, marked on the chart; the median year is -18.3 C (-0.9 F).
Coldest night (TNn) at Cahokia by year
Year
Coldest night (TNn)
1969
-10.6 C (12.9 F)
1970
-21.1 C (-6.0 F)
1971
-17.2 C (1.0 F)
1972
-20.6 C (-5.1 F)
1973
-17.2 C (1.0 F)
1974
-19.4 C (-2.9 F)
1975
-16.1 C (3.0 F)
1976
-21.7 C (-7.1 F)
1977
-28.3 C (-18.9 F)
1978
-21.7 C (-7.1 F)
1979
-24.4 C (-11.9 F)
1980
-18.3 C (-0.9 F)
1981
-17.2 C (1.0 F)
1982
-26.1 C (-15.0 F)
1983
-11.7 C (10.9 F)
1984
-12.2 C (10.0 F)
1985
-27.2 C (-17.0 F)
1986
-20.0 C (-4.0 F)
1987
-17.8 C (0.0 F)
1988
-21.7 C (-7.1 F)
1989
-28.3 C (-18.9 F)
1990
-17.2 C (1.0 F)
1991
-14.4 C (6.1 F)
1992
-14.4 C (6.1 F)
1993
-21.1 C (-6.0 F)
1994
-22.2 C (-8.0 F)
1995
-16.7 C (1.9 F)
1996
-25.0 C (-13.0 F)
1997
-20.0 C (-4.0 F)
1998
-13.3 C (8.1 F)
1999
-21.7 C (-7.1 F)
2000
-18.3 C (-0.9 F)
2001
-20.0 C (-4.0 F)
2002
-14.4 C (6.1 F)
2004
-13.9 C (7.0 F)
2005
-15.6 C (3.9 F)
2006
-15.0 C (5.0 F)
2007
-16.7 C (1.9 F)
2008
-16.1 C (3.0 F)
2009
-19.4 C (-2.9 F)
2010
-20.6 C (-5.1 F)
2011
-16.7 C (1.9 F)
2012
-12.8 C (9.0 F)
Wettest day (Rx1day)
The wettest day of the year at Cahokia, 1969 to 2012. The record is 111.0 mm (4.4 in) in 1990, marked on the chart; the median year is 60.7 mm (2.4 in).
Wettest day (Rx1day) at Cahokia by year
Year
Wettest day (Rx1day)
1969
59.4 mm (2.3 in)
1970
54.6 mm (2.1 in)
1971
83.8 mm (3.3 in)
1972
61.0 mm (2.4 in)
1973
36.1 mm (1.4 in)
1974
50.8 mm (2.0 in)
1975
61.0 mm (2.4 in)
1976
44.5 mm (1.8 in)
1977
78.7 mm (3.1 in)
1978
39.6 mm (1.6 in)
1979
55.9 mm (2.2 in)
1980
53.3 mm (2.1 in)
1981
78.5 mm (3.1 in)
1982
64.8 mm (2.6 in)
1983
52.1 mm (2.1 in)
1984
46.0 mm (1.8 in)
1985
57.2 mm (2.3 in)
1986
57.2 mm (2.3 in)
1987
62.2 mm (2.4 in)
1988
48.3 mm (1.9 in)
1989
71.9 mm (2.8 in)
1990
111.0 mm (4.4 in)
1991
88.1 mm (3.5 in)
1992
58.4 mm (2.3 in)
1993
80.0 mm (3.1 in)
1994
76.2 mm (3.0 in)
1995
88.9 mm (3.5 in)
1996
76.2 mm (3.0 in)
1997
40.6 mm (1.6 in)
1998
108.5 mm (4.3 in)
1999
62.7 mm (2.5 in)
2000
67.8 mm (2.7 in)
2001
48.3 mm (1.9 in)
2002
68.1 mm (2.7 in)
2004
57.9 mm (2.3 in)
2005
60.7 mm (2.4 in)
2006
50.8 mm (2.0 in)
2007
58.4 mm (2.3 in)
2008
69.1 mm (2.7 in)
2009
64.0 mm (2.5 in)
2010
58.9 mm (2.3 in)
2011
79.2 mm (3.1 in)
2012
41.7 mm (1.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Cahokia, 1969 to 2012. The record is 182.6 mm (7.2 in) in 1995, marked on the chart; the median year is 99.8 mm (3.9 in).
Wettest five days (Rx5day) at Cahokia by year
Year
Wettest five days (Rx5day)
1969
113.8 mm (4.5 in)
1970
97.4 mm (3.8 in)
1971
135.9 mm (5.4 in)
1972
128.3 mm (5.1 in)
1973
79.1 mm (3.1 in)
1974
90.5 mm (3.6 in)
1975
85.6 mm (3.4 in)
1976
80.8 mm (3.2 in)
1977
89.1 mm (3.5 in)
1978
83.6 mm (3.3 in)
1979
101.1 mm (4.0 in)
1980
73.6 mm (2.9 in)
1981
99.8 mm (3.9 in)
1982
98.6 mm (3.9 in)
1983
66.3 mm (2.6 in)
1984
85.2 mm (3.4 in)
1985
112.1 mm (4.4 in)
1986
161.8 mm (6.4 in)
1987
149.7 mm (5.9 in)
1988
74.5 mm (2.9 in)
1989
77.7 mm (3.1 in)
1990
172.2 mm (6.8 in)
1991
127.2 mm (5.0 in)
1992
101.9 mm (4.0 in)
1993
123.4 mm (4.9 in)
1994
134.9 mm (5.3 in)
1995
182.6 mm (7.2 in)
1996
106.4 mm (4.2 in)
1997
60.5 mm (2.4 in)
1998
125.0 mm (4.9 in)
1999
95.2 mm (3.7 in)
2000
118.0 mm (4.6 in)
2001
81.5 mm (3.2 in)
2002
89.8 mm (3.5 in)
2004
96.6 mm (3.8 in)
2005
149.7 mm (5.9 in)
2006
73.7 mm (2.9 in)
2007
80.9 mm (3.2 in)
2008
110.0 mm (4.3 in)
2009
101.5 mm (4.0 in)
2010
104.3 mm (4.1 in)
2011
117.5 mm (4.6 in)
2012
82.8 mm (3.3 in)
Longest dry spell (CDD)
The longest dry spell of the year at Cahokia, 1969 to 2012. The record is 42 days in 1979, marked on the chart; the median year is 20 days.
Longest dry spell (CDD) at Cahokia by year
Year
Longest dry spell (CDD)
1969
25 days
1970
28 days
1971
18 days
1972
21 days
1973
16 days
1974
15 days
1975
14 days
1976
26 days
1977
20 days
1978
20 days
1979
42 days
1980
26 days
1981
20 days
1982
19 days
1983
31 days
1984
11 days
1985
33 days
1986
27 days
1987
14 days
1988
15 days
1989
20 days
1990
19 days
1991
18 days
1992
20 days
1993
17 days
1994
16 days
1995
26 days
1996
20 days
1997
15 days
1998
12 days
1999
20 days
2000
13 days
2001
16 days
2002
21 days
2004
21 days
2005
21 days
2006
21 days
2007
23 days
2008
20 days
2009
26 days
2010
21 days
2011
18 days
2012
12 days
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
27 years with a frost
Across 27 years with a frost, the median last spring frost at Cahokia falls on 9 April and the median first autumn frost on 18 October, which leaves a median of 192 days between them.
Fitted over all years, the growing season changes by +4.7 days per decade at this station.
Frost dates and growing season at Cahokia
Measure
Median, all years
Earliest period
Recent period (1972 to 2010)
Recent against earliest
Fitted trend
Last spring frost
9 April
n/a
9 April
n/a
-1.6 days per decade
First autumn frost
18 October
n/a
18 October
n/a
+3.1 days per decade
Growing days
192 days
n/a
192 days
n/a
+4.7 days per decade
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
30 years, 1972 to 2010
A day with at least 61.8 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 125.3 mm (4.9 in) of rain is expected about once in 100 years.
Rainfall return levels at Cahokia: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
61.8 mm (2.4 in)
5 years
77.4 mm (3.0 in)
10 years
88.3 mm (3.5 in)
25 years
102.7 mm (4.0 in)
50 years
113.8 mm (4.5 in)
Longer than the 30 years of record
100 years
125.3 mm (4.9 in)
Longer than the 30 years of record
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 30 years of values from 1972 to 2010.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 111.0 mm (4.4 in) in 1990; 108.5 mm (4.3 in) in 1998; 88.9 mm (3.5 in) in 1995.
Download the Data
Data for Cahokia standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Cahokia threshold days by year: CSV or JSON. Field meanings are on the data page.
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-13 (13 October 2026). Records are computed by this site and are not official.