Record envelope, standing records and threshold days for Joliet (USC00244506), Montana, United States, with 70 years of record.
Key Facts for Joliet
Joliet (USC00244506) is a weather station in Montana, United States at 45.47 latitude and -109.01 longitude, 1,170 m (3,838 ft) above sea level.
The station reports from 1951 to 2020, 70 years of record.
1,464 records set at Joliet still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Joliet tied a daily record high maximum temperature of 13.9 C (57.0 F) on 21 December 2020.
About the Station
Location: Montana, United States, 45.47 latitude, -109.01 longitude.
Elevation: 1,170 m (3,838 ft).
Period of record: 1951 to 2020, 70 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 Joliet. 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 Joliet, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.2 C (63.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Feb
22.8 C (73.0 F)
-37.2 C (-35.0 F)
n/a
n/a
Mar
25.6 C (78.1 F)
-35.6 C (-32.1 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-23.3 C (-9.9 F)
n/a
n/a
May
34.4 C (93.9 F)
-9.4 C (15.1 F)
n/a
n/a
Jun
38.9 C (102.0 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
41.1 C (106.0 F)
0.0 C (32.0 F)
n/a
n/a
Aug
40.0 C (104.0 F)
-1.7 C (28.9 F)
n/a
n/a
Sep
38.3 C (100.9 F)
-7.8 C (18.0 F)
n/a
n/a
Oct
32.8 C (91.0 F)
-23.3 C (-9.9 F)
n/a
n/a
Nov
23.9 C (75.0 F)
-33.3 C (-27.9 F)
n/a
n/a
Dec
20.6 C (69.1 F)
-39.4 C (-38.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Joliet still stand. 1968 holds the most, with 39.
Standing records at Joliet by the year they were set
Year set
Standing records
1956
5
1957
23
1958
24
1959
26
1960
24
1961
27
1962
30
1963
32
1964
14
1965
32
1966
21
1967
19
1968
39
1969
27
1970
16
1971
19
1972
33
1973
20
1974
21
1975
16
1976
12
1977
19
1978
18
1979
9
1980
23
1981
17
1982
19
1983
29
1984
21
1985
37
1986
27
1987
31
1988
39
1989
21
1990
33
1991
19
1992
28
1993
19
1994
22
1995
19
1996
33
1997
28
1998
18
1999
26
2000
17
2001
13
2002
27
2003
35
2004
12
2005
32
2006
14
2007
16
2008
16
2009
27
2010
20
2011
15
2012
16
2013
21
2014
21
2015
17
2016
9
2017
14
2018
23
2019
30
2020
34
All-Time Record Progression
3 new records
3 all-time records were set at Joliet between 2 February 1989 and 13 July 2002. Each dot is a new record.
When Joliet set new all-time records
Date
Kind
Detail
1989-02-02
Record low maximum temperature
Record low maximum temperature -29.4 C (-20.9 F)
1997-04-05
Record daily snowfall
Record daily snowfall 48.3 cm (19.0 in)
2002-07-13
Record high maximum temperature
Record high maximum temperature 41.1 C (106.0 F)
Wettest Day of Each Month
May: 108.0 mm (4.3 in)
The wettest day on record for each calendar month at Joliet. The most was 108.0 mm (4.3 in) on 18 May 1978.
Record daily precipitation for each month at Joliet
Month
Record daily precipitation (mm)
Date
Jan
24.1 mm (0.9 in)
26 January 1975
Feb
16.3 mm (0.6 in)
18 February 1955
Mar
33.3 mm (1.3 in)
23 March 1973
Apr
52.3 mm (2.1 in)
25 April 1964
May
108.0 mm (4.3 in)
18 May 1978
Jun
106.7 mm (4.2 in)
14 June 2001
Jul
36.8 mm (1.4 in)
6 July 1994
Aug
50.8 mm (2.0 in)
15 August 1987
Sep
70.9 mm (2.8 in)
18 September 1978
Oct
66.0 mm (2.6 in)
31 October 1974
Nov
32.3 mm (1.3 in)
1 November 1957
Dec
17.8 mm (0.7 in)
4 December 2013
Period of Record Coverage
1956 to 2020
Complete yearUnder 90 percent of days
65 years of record at Joliet, 1956 to 2020. 4 years have data for under 90 percent of days and are left out of rankings: 1956, 1990, 1995, 2009.
Cooler than the station meanWarmer than the station mean
One stripe for each of 58 complete years at Joliet, 1957 to 2020. Blue stripes are years cooler than the station's own mean of 7.6 C (45.7 F); red stripes are warmer. The coolest year was 2019, at 5.0 C (41.0 F), and the warmest was 1999, at 9.7 C (49.4 F). The strongest colour marks a difference of 2.7 C (4.9 F).
Annual mean temperature at Joliet as warming stripes, 1957 to 2020
Year
Annual mean temperature
Difference from the station mean
1957
7.3 C
-0.36 C
1958
8.4 C
+0.78 C
1959
7.5 C
-0.13 C
1960
7.5 C
-0.12 C
1961
7.7 C
+0.10 C
1962
7.9 C
+0.24 C
1963
8.2 C
+0.59 C
1964
7.4 C
-0.25 C
1965
7.1 C
-0.54 C
1966
7.6 C
-0.02 C
1967
7.1 C
-0.53 C
1968
6.5 C
-1.11 C
1969
7.1 C
-0.53 C
1970
7.6 C
+0.01 C
1971
7.4 C
-0.23 C
1972
7.0 C
-0.65 C
1973
7.7 C
+0.07 C
1974
8.3 C
+0.69 C
1975
6.5 C
-1.09 C
1976
8.7 C
+1.08 C
1978
6.0 C
-1.60 C
1980
8.3 C
+0.67 C
1981
9.4 C
+1.76 C
1982
6.9 C
-0.70 C
1983
8.2 C
+0.59 C
1984
7.8 C
+0.19 C
1985
6.8 C
-0.84 C
1986
8.9 C
+1.25 C
1987
9.4 C
+1.73 C
1988
9.2 C
+1.61 C
1989
7.3 C
-0.29 C
1991
8.5 C
+0.89 C
1992
8.9 C
+1.22 C
1993
6.8 C
-0.80 C
1994
8.9 C
+1.29 C
1996
5.8 C
-1.80 C
1997
8.1 C
+0.45 C
1998
8.9 C
+1.24 C
1999
9.7 C
+2.03 C
2000
8.2 C
+0.57 C
2001
8.3 C
+0.66 C
2002
6.9 C
-0.69 C
2003
8.4 C
+0.78 C
2004
8.1 C
+0.45 C
2005
7.5 C
-0.10 C
2006
8.4 C
+0.76 C
2007
8.1 C
+0.46 C
2008
6.8 C
-0.79 C
2011
6.2 C
-1.44 C
2012
8.1 C
+0.47 C
2013
6.6 C
-1.03 C
2014
6.2 C
-1.42 C
2015
7.7 C
+0.06 C
2016
7.8 C
+0.18 C
2017
6.7 C
-0.90 C
2018
5.8 C
-1.81 C
2019
5.0 C
-2.64 C
2020
7.2 C
-0.41 C
The fitted trend in annual mean temperature here over 1957 to 2020 is -0.1 C (-0.2 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.4 to 0.1) per decade. The slope is a straight line fitted to 58 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Joliet
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.2 to 0.1) per decade
-0.1 F (-0.4 to 0.1) per decade
1957 to 2020
58
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.2 to 0.1) per decade
-0.2 F (-0.4 to 0.1) per decade
1957 to 2020
58
Not clearly different from zero
Mean daily minimum
-0.1 C (-0.2 to 0.1) per decade
-0.1 F (-0.3 to 0.1) per decade
1957 to 2020
58
Not clearly different from zero
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
1951 to 2020
Yearly extremes at Joliet: 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)
2002
37.8 C (100.0 F)
65
Coldest night (TNn)
-39.4 C (-38.9 F)
1983
-31.1 C (-24.0 F)
65
Wettest day (Rx1day)
108.0 mm (4.3 in)
1978
33.2 mm (1.3 in)
70
Wettest five days (Rx5day)
175.6 mm (6.9 in)
1978
51.4 mm (2.0 in)
70
Longest dry spell (CDD)
58 days
2008
28 days
70
Hottest day (TXx)
The hottest day of the year at Joliet, 1951 to 2020. The record is 41.1 C (106.0 F) in 2002, marked on the chart; the median year is 37.8 C (100.0 F).
Hottest day (TXx) at Joliet by year
Year
Hottest day (TXx)
1951
n/a
1952
n/a
1953
n/a
1954
n/a
1955
n/a
1956
25.0 C (77.0 F)
1957
38.9 C (102.0 F)
1958
36.7 C (98.1 F)
1959
38.3 C (100.9 F)
1960
40.0 C (104.0 F)
1961
40.0 C (104.0 F)
1962
36.1 C (97.0 F)
1963
38.3 C (100.9 F)
1964
37.8 C (100.0 F)
1965
37.8 C (100.0 F)
1966
37.2 C (99.0 F)
1967
36.7 C (98.1 F)
1968
37.2 C (99.0 F)
1969
37.2 C (99.0 F)
1970
36.7 C (98.1 F)
1971
37.8 C (100.0 F)
1972
35.6 C (96.1 F)
1973
38.3 C (100.9 F)
1974
36.7 C (98.1 F)
1975
37.8 C (100.0 F)
1976
36.7 C (98.1 F)
1977
39.4 C (102.9 F)
1978
36.1 C (97.0 F)
1979
36.1 C (97.0 F)
1980
36.7 C (98.1 F)
1981
37.2 C (99.0 F)
1982
37.2 C (99.0 F)
1983
38.3 C (100.9 F)
1984
37.8 C (100.0 F)
1985
37.8 C (100.0 F)
1986
37.2 C (99.0 F)
1987
35.6 C (96.1 F)
1988
38.9 C (102.0 F)
1989
40.0 C (104.0 F)
1990
38.3 C (100.9 F)
1991
37.8 C (100.0 F)
1992
35.6 C (96.1 F)
1993
34.4 C (93.9 F)
1994
35.6 C (96.1 F)
1995
38.3 C (100.9 F)
1996
37.8 C (100.0 F)
1997
35.6 C (96.1 F)
1998
36.7 C (98.1 F)
1999
38.3 C (100.9 F)
2000
37.8 C (100.0 F)
2001
38.9 C (102.0 F)
2002
41.1 C (106.0 F)
2003
40.0 C (104.0 F)
2004
36.7 C (98.1 F)
2005
40.0 C (104.0 F)
2006
39.4 C (102.9 F)
2007
40.0 C (104.0 F)
2008
38.3 C (100.9 F)
2009
35.6 C (96.1 F)
2010
37.8 C (100.0 F)
2011
37.2 C (99.0 F)
2012
38.9 C (102.0 F)
2013
36.1 C (97.0 F)
2014
35.6 C (96.1 F)
2015
37.8 C (100.0 F)
2016
37.2 C (99.0 F)
2017
37.2 C (99.0 F)
2018
37.8 C (100.0 F)
2019
36.1 C (97.0 F)
2020
38.3 C (100.9 F)
Coldest night (TNn)
The coldest night of the year at Joliet, 1951 to 2020. The record is -39.4 C (-38.9 F) in 1983, marked on the chart; the median year is -31.1 C (-24.0 F).
Coldest night (TNn) at Joliet by year
Year
Coldest night (TNn)
1951
n/a
1952
n/a
1953
n/a
1954
n/a
1955
n/a
1956
-27.2 C (-17.0 F)
1957
-35.0 C (-31.0 F)
1958
-23.9 C (-11.0 F)
1959
-33.9 C (-29.0 F)
1960
-30.0 C (-22.0 F)
1961
-32.2 C (-26.0 F)
1962
-35.0 C (-31.0 F)
1963
-36.7 C (-34.1 F)
1964
-33.9 C (-29.0 F)
1965
-31.7 C (-25.1 F)
1966
-30.0 C (-22.0 F)
1967
-28.9 C (-20.0 F)
1968
-35.6 C (-32.1 F)
1969
-32.8 C (-27.0 F)
1970
-28.3 C (-18.9 F)
1971
-28.9 C (-20.0 F)
1972
-35.6 C (-32.1 F)
1973
-32.2 C (-26.0 F)
1974
-32.8 C (-27.0 F)
1975
-28.3 C (-18.9 F)
1976
-31.1 C (-24.0 F)
1977
-32.2 C (-26.0 F)
1978
-32.2 C (-26.0 F)
1979
-30.6 C (-23.1 F)
1980
-33.3 C (-27.9 F)
1981
-35.0 C (-31.0 F)
1982
-31.7 C (-25.1 F)
1983
-39.4 C (-38.9 F)
1984
-30.0 C (-22.0 F)
1985
-31.7 C (-25.1 F)
1986
-28.9 C (-20.0 F)
1987
-26.1 C (-15.0 F)
1988
-27.8 C (-18.0 F)
1989
-37.2 C (-35.0 F)
1990
-36.1 C (-33.0 F)
1991
-30.0 C (-22.0 F)
1992
-28.3 C (-18.9 F)
1993
-28.3 C (-18.9 F)
1994
-27.2 C (-17.0 F)
1995
-22.2 C (-8.0 F)
1996
-36.1 C (-33.0 F)
1997
-38.3 C (-36.9 F)
1998
-28.3 C (-18.9 F)
1999
-22.8 C (-9.0 F)
2000
-26.7 C (-16.1 F)
2001
-27.2 C (-17.0 F)
2002
-26.1 C (-15.0 F)
2003
-32.2 C (-26.0 F)
2004
-31.1 C (-24.0 F)
2005
-30.0 C (-22.0 F)
2006
-27.8 C (-18.0 F)
2007
-33.9 C (-29.0 F)
2008
-31.1 C (-24.0 F)
2009
-25.6 C (-14.1 F)
2010
-32.2 C (-26.0 F)
2011
-29.4 C (-20.9 F)
2012
-23.9 C (-11.0 F)
2013
-33.3 C (-27.9 F)
2014
-33.9 C (-29.0 F)
2015
-26.7 C (-16.1 F)
2016
-32.8 C (-27.0 F)
2017
-31.1 C (-24.0 F)
2018
-31.7 C (-25.1 F)
2019
-35.6 C (-32.1 F)
2020
-23.9 C (-11.0 F)
Wettest day (Rx1day)
The wettest day of the year at Joliet, 1951 to 2020. The record is 108.0 mm (4.3 in) in 1978, marked on the chart; the median year is 33.2 mm (1.3 in).
Wettest day (Rx1day) at Joliet by year
Year
Wettest day (Rx1day)
1951
16.8 mm (0.7 in)
1952
35.6 mm (1.4 in)
1953
34.5 mm (1.4 in)
1954
16.3 mm (0.6 in)
1955
23.9 mm (0.9 in)
1956
25.9 mm (1.0 in)
1957
52.1 mm (2.1 in)
1958
31.2 mm (1.2 in)
1959
34.0 mm (1.3 in)
1960
28.4 mm (1.1 in)
1961
38.4 mm (1.5 in)
1962
42.7 mm (1.7 in)
1963
25.4 mm (1.0 in)
1964
52.3 mm (2.1 in)
1965
26.7 mm (1.1 in)
1966
32.0 mm (1.3 in)
1967
31.8 mm (1.3 in)
1968
47.0 mm (1.9 in)
1969
83.8 mm (3.3 in)
1970
82.6 mm (3.3 in)
1971
31.8 mm (1.3 in)
1972
27.4 mm (1.1 in)
1973
33.3 mm (1.3 in)
1974
66.0 mm (2.6 in)
1975
41.4 mm (1.6 in)
1976
33.0 mm (1.3 in)
1977
24.6 mm (1.0 in)
1978
108.0 mm (4.3 in)
1979
26.4 mm (1.0 in)
1980
32.0 mm (1.3 in)
1981
58.7 mm (2.3 in)
1982
34.8 mm (1.4 in)
1983
26.7 mm (1.1 in)
1984
37.8 mm (1.5 in)
1985
16.8 mm (0.7 in)
1986
42.7 mm (1.7 in)
1987
64.0 mm (2.5 in)
1988
66.5 mm (2.6 in)
1989
34.3 mm (1.4 in)
1990
24.1 mm (0.9 in)
1991
20.3 mm (0.8 in)
1992
43.7 mm (1.7 in)
1993
29.5 mm (1.2 in)
1994
36.8 mm (1.4 in)
1995
22.9 mm (0.9 in)
1996
40.6 mm (1.6 in)
1997
51.3 mm (2.0 in)
1998
21.6 mm (0.9 in)
1999
24.4 mm (1.0 in)
2000
33.5 mm (1.3 in)
2001
106.7 mm (4.2 in)
2002
28.7 mm (1.1 in)
2003
27.2 mm (1.1 in)
2004
23.6 mm (0.9 in)
2005
21.3 mm (0.8 in)
2006
33.8 mm (1.3 in)
2007
39.1 mm (1.5 in)
2008
30.0 mm (1.2 in)
2009
25.1 mm (1.0 in)
2010
33.0 mm (1.3 in)
2011
83.8 mm (3.3 in)
2012
25.4 mm (1.0 in)
2013
38.1 mm (1.5 in)
2014
45.7 mm (1.8 in)
2015
25.4 mm (1.0 in)
2016
34.5 mm (1.4 in)
2017
36.1 mm (1.4 in)
2018
43.2 mm (1.7 in)
2019
30.5 mm (1.2 in)
2020
29.0 mm (1.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Joliet, 1951 to 2020. The record is 175.6 mm (6.9 in) in 1978, marked on the chart; the median year is 51.4 mm (2.0 in).
Wettest five days (Rx5day) at Joliet by year
Year
Wettest five days (Rx5day)
1951
34.3 mm (1.4 in)
1952
61.7 mm (2.4 in)
1953
41.6 mm (1.6 in)
1954
25.2 mm (1.0 in)
1955
71.0 mm (2.8 in)
1956
34.8 mm (1.4 in)
1957
86.9 mm (3.4 in)
1958
51.3 mm (2.0 in)
1959
46.8 mm (1.8 in)
1960
37.4 mm (1.5 in)
1961
64.1 mm (2.5 in)
1962
93.8 mm (3.7 in)
1963
50.0 mm (2.0 in)
1964
99.0 mm (3.9 in)
1965
51.1 mm (2.0 in)
1966
43.0 mm (1.7 in)
1967
51.4 mm (2.0 in)
1968
71.8 mm (2.8 in)
1969
110.7 mm (4.4 in)
1970
90.5 mm (3.6 in)
1971
71.1 mm (2.8 in)
1972
46.1 mm (1.8 in)
1973
56.5 mm (2.2 in)
1974
86.5 mm (3.4 in)
1975
97.0 mm (3.8 in)
1976
66.2 mm (2.6 in)
1977
40.1 mm (1.6 in)
1978
175.6 mm (6.9 in)
1979
33.5 mm (1.3 in)
1980
59.2 mm (2.3 in)
1981
87.9 mm (3.5 in)
1982
52.9 mm (2.1 in)
1983
35.0 mm (1.4 in)
1984
67.3 mm (2.6 in)
1985
29.0 mm (1.1 in)
1986
53.6 mm (2.1 in)
1987
74.7 mm (2.9 in)
1988
67.5 mm (2.7 in)
1989
41.7 mm (1.6 in)
1990
29.2 mm (1.1 in)
1991
71.3 mm (2.8 in)
1992
86.4 mm (3.4 in)
1993
51.3 mm (2.0 in)
1994
42.7 mm (1.7 in)
1995
43.7 mm (1.7 in)
1996
73.1 mm (2.9 in)
1997
51.3 mm (2.0 in)
1998
47.7 mm (1.9 in)
1999
28.8 mm (1.1 in)
2000
34.0 mm (1.3 in)
2001
127.0 mm (5.0 in)
2002
51.0 mm (2.0 in)
2003
42.5 mm (1.7 in)
2004
26.6 mm (1.0 in)
2005
56.9 mm (2.2 in)
2006
51.9 mm (2.0 in)
2007
51.8 mm (2.0 in)
2008
79.5 mm (3.1 in)
2009
29.9 mm (1.2 in)
2010
41.9 mm (1.6 in)
2011
116.6 mm (4.6 in)
2012
47.5 mm (1.9 in)
2013
44.5 mm (1.8 in)
2014
65.1 mm (2.6 in)
2015
45.5 mm (1.8 in)
2016
45.6 mm (1.8 in)
2017
61.8 mm (2.4 in)
2018
64.3 mm (2.5 in)
2019
38.8 mm (1.5 in)
2020
41.4 mm (1.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Joliet, 1951 to 2020. The record is 58 days in 2008, marked on the chart; the median year is 28 days.
Longest dry spell (CDD) at Joliet by year
Year
Longest dry spell (CDD)
1951
18 days
1952
35 days
1953
47 days
1954
41 days
1955
39 days
1956
21 days
1957
29 days
1958
20 days
1959
24 days
1960
42 days
1961
28 days
1962
39 days
1963
31 days
1964
25 days
1965
26 days
1966
23 days
1967
47 days
1968
22 days
1969
42 days
1970
26 days
1971
20 days
1972
23 days
1973
39 days
1974
28 days
1975
29 days
1976
35 days
1977
37 days
1978
29 days
1979
42 days
1980
22 days
1981
29 days
1982
17 days
1983
25 days
1984
23 days
1985
30 days
1986
25 days
1987
26 days
1988
33 days
1989
19 days
1990
19 days
1991
19 days
1992
49 days
1993
22 days
1994
26 days
1995
16 days
1996
45 days
1997
17 days
1998
21 days
1999
55 days
2000
23 days
2001
29 days
2002
25 days
2003
33 days
2004
27 days
2005
29 days
2006
30 days
2007
41 days
2008
58 days
2009
23 days
2010
40 days
2011
23 days
2012
31 days
2013
45 days
2014
26 days
2015
20 days
2016
49 days
2017
29 days
2018
34 days
2019
22 days
2020
23 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
58 years with a frost
Across 58 years with a frost, the median last spring frost at Joliet falls on 24 May and the median first autumn frost on 19 September, which leaves a median of 117 days between them.
Fitted over all years, the growing season changes by -0.1 days per decade at this station.
Frost dates and growing season at Joliet
Measure
Median, all years
Earliest period
Recent period (1987 to 2020)
Recent against earliest
Fitted trend
Last spring frost
24 May
n/a
22 May
n/a
+0.4 days per decade
First autumn frost
19 September
n/a
17 September
n/a
+0.3 days per decade
Growing days
117 days
n/a
116 days
n/a
-0.1 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
66 years, 1952 to 2020
A day with at least 33.6 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 122.3 mm (4.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Joliet: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
33.6 mm (1.3 in)
5 years
47.7 mm (1.9 in)
10 years
60.0 mm (2.4 in)
25 years
80.0 mm (3.1 in)
50 years
99.0 mm (3.9 in)
100 years
122.3 mm (4.8 in)
Longer than the 66 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, 66 years of values from 1952 to 2020.
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: 108.0 mm (4.3 in) in 1978; 106.7 mm (4.2 in) in 2001; 83.8 mm (3.3 in) in 1969.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Joliet, at 2011. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 2011 ran 0.4 C (0.8 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Joliet, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
2011
-0.4
-0.8
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Climate Twins
2004 to 2020 against 1961 to 1990
Over 2004 to 2020, Joliet had a mean temperature of 7.1 C (44.8 F) and 383.1 mm (15.1 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Echo Dam (United States, 538 km away), Arbon 2 NW (United States, 436 km away) and Billy Creek (United States, 234 km away).
Climate twins of Joliet: stations whose 1961 to 1990 climate is closest to its 2004 to 2020 climate
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Data for Joliet standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Joliet 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.