Record envelope, standing records and threshold days for Harrold 12 SSW (USC00393608), South Dakota, United States, with 59 years of record.
Key Facts for Harrold 12 SSW
Harrold 12 SSW (USC00393608) is a weather station in South Dakota, United States at 44.36 latitude and -99.80 longitude, 519 m (1,701 ft) above sea level.
The station reports from 1963 to 2021, 59 years of record.
1,464 records set at Harrold 12 SSW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Harrold 12 SSW set a daily record high minimum temperature of 6.1 C (43.0 F) on 27 October 2021.
About the Station
Location: South Dakota, United States, 44.36 latitude, -99.80 longitude.
Elevation: 519 m (1,701 ft).
Period of record: 1963 to 2021, 59 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 Harrold 12 SSW. 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 Harrold 12 SSW, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
20.0 C (68.0 F)
-40.0 C (-40.0 F)
n/a
n/a
Feb
23.3 C (73.9 F)
-42.2 C (-44.0 F)
n/a
n/a
Mar
31.1 C (88.0 F)
-34.4 C (-29.9 F)
n/a
n/a
Apr
35.6 C (96.1 F)
-22.2 C (-8.0 F)
n/a
n/a
May
39.4 C (102.9 F)
-11.7 C (10.9 F)
n/a
n/a
Jun
44.4 C (111.9 F)
-4.4 C (24.1 F)
n/a
n/a
Jul
45.0 C (113.0 F)
0.0 C (32.0 F)
n/a
n/a
Aug
45.0 C (113.0 F)
0.0 C (32.0 F)
n/a
n/a
Sep
42.8 C (109.0 F)
-10.0 C (14.0 F)
n/a
n/a
Oct
36.7 C (98.1 F)
-18.9 C (-2.0 F)
n/a
n/a
Nov
28.3 C (82.9 F)
-30.0 C (-22.0 F)
n/a
n/a
Dec
20.6 C (69.1 F)
-38.9 C (-38.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Harrold 12 SSW still stand. 1985 holds the most, with 51.
Standing records at Harrold 12 SSW by the year they were set
Year set
Standing records
1963
14
1964
39
1965
38
1966
34
1967
31
1968
26
1969
36
1970
31
1971
31
1972
32
1973
20
1974
33
1975
14
1976
47
1977
32
1978
31
1979
27
1980
16
1981
27
1982
19
1983
33
1984
22
1985
51
1986
21
1987
34
1988
46
1989
43
1990
44
1991
43
1992
47
1993
22
1994
25
1995
29
1996
12
2000
28
2003
11
2004
29
2005
27
2006
34
2007
17
2008
11
2009
28
2010
11
2011
20
2012
39
2013
25
2014
36
2015
23
2016
16
2017
13
2018
16
2019
10
2021
20
Wettest Day of Each Month
Jun: 105.2 mm (4.1 in)
The wettest day on record for each calendar month at Harrold 12 SSW. The most was 105.2 mm (4.1 in) on 25 June 1969.
Record daily precipitation for each month at Harrold 12 SSW
Month
Record daily precipitation (mm)
Date
Jan
16.3 mm (0.6 in)
16 January 1985
Feb
24.1 mm (0.9 in)
24 February 1977
Mar
63.8 mm (2.5 in)
27 March 2004
Apr
57.7 mm (2.3 in)
27 April 1964
May
55.6 mm (2.2 in)
31 May 1983
Jun
105.2 mm (4.1 in)
25 June 1969
Jul
86.1 mm (3.4 in)
31 July 2017
Aug
49.5 mm (1.9 in)
16 August 2009
Sep
54.6 mm (2.1 in)
19 September 1986
Oct
49.0 mm (1.9 in)
9 October 1982
Nov
31.8 mm (1.3 in)
13 November 1993
Dec
19.3 mm (0.8 in)
29 December 1972
Period of Record Coverage
1963 to 2021
Complete yearUnder 90 percent of days
54 years of record at Harrold 12 SSW, 1963 to 2021. 13 years have data for under 90 percent of days and are left out of rankings: 1963, 1973, 1974, 1975, 1978, 1996, 2000, 2003 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 38 complete years at Harrold 12 SSW, 1964 to 2016. Blue stripes are years cooler than the station's own mean of 7.3 C (45.1 F); red stripes are warmer. The coolest year was 2014, at 5.5 C (41.8 F), and the warmest was 1987, at 9.6 C (49.3 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at Harrold 12 SSW as warming stripes, 1964 to 2016
Year
Annual mean temperature
Difference from the station mean
1964
7.6 C
+0.32 C
1965
6.9 C
-0.40 C
1966
6.8 C
-0.52 C
1967
7.4 C
+0.13 C
1968
6.8 C
-0.48 C
1969
6.8 C
-0.47 C
1970
6.9 C
-0.40 C
1971
6.9 C
-0.42 C
1972
6.3 C
-1.01 C
1976
8.0 C
+0.76 C
1981
8.8 C
+1.51 C
1982
6.0 C
-1.26 C
1983
7.4 C
+0.17 C
1984
7.7 C
+0.40 C
1985
6.1 C
-1.22 C
1986
7.8 C
+0.54 C
1987
9.6 C
+2.34 C
1988
8.3 C
+0.98 C
1989
7.1 C
-0.21 C
1990
8.6 C
+1.29 C
1991
8.7 C
+1.39 C
1992
7.7 C
+0.39 C
1993
5.8 C
-1.52 C
1994
6.9 C
-0.39 C
1995
7.3 C
+0.07 C
2004
7.4 C
+0.17 C
2005
7.9 C
+0.67 C
2006
8.5 C
+1.21 C
2007
7.7 C
+0.46 C
2008
5.9 C
-1.42 C
2009
5.8 C
-1.46 C
2010
6.5 C
-0.80 C
2011
6.1 C
-1.22 C
2012
9.0 C
+1.72 C
2013
6.0 C
-1.32 C
2014
5.5 C
-1.81 C
2015
7.9 C
+0.62 C
2016
8.6 C
+1.28 C
The fitted trend in annual mean temperature here over 1964 to 2016 is 0.00 C (-0.21 to 0.21) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.01 F (-0.38 to 0.37) per decade. The slope is a straight line fitted to 38 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Harrold 12 SSW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.00 C (-0.21 to 0.21) per decade
-0.01 F (-0.38 to 0.37) per decade
1964 to 2016
38
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.4 to 0.2) per decade
-0.1 F (-0.6 to 0.3) per decade
1964 to 2016
38
Not clearly different from zero
Mean daily minimum
0.1 C (-0.1 to 0.3) per decade
0.1 F (-0.2 to 0.5) per decade
1964 to 2016
38
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
1963 to 2021
Yearly extremes at Harrold 12 SSW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.0 C (113.0 F)
1965
40.6 C (105.1 F)
54
Coldest night (TNn)
-42.2 C (-44.0 F)
1994
-33.0 C (-27.5 F)
54
Wettest day (Rx1day)
105.2 mm (4.1 in)
1969
44.1 mm (1.7 in)
54
Wettest five days (Rx5day)
135.7 mm (5.3 in)
1969
62.4 mm (2.5 in)
54
Longest dry spell (CDD)
105 days
2012
36 days
54
Hottest day (TXx)
The hottest day of the year at Harrold 12 SSW, 1963 to 2021. The record is 45.0 C (113.0 F) in 1965, marked on the chart; the median year is 40.6 C (105.1 F).
Hottest day (TXx) at Harrold 12 SSW by year
Year
Hottest day (TXx)
1963
37.2 C (99.0 F)
1964
42.2 C (108.0 F)
1965
45.0 C (113.0 F)
1966
43.3 C (109.9 F)
1967
38.9 C (102.0 F)
1968
39.4 C (102.9 F)
1969
40.6 C (105.1 F)
1970
40.6 C (105.1 F)
1971
41.1 C (106.0 F)
1972
38.9 C (102.0 F)
1973
43.3 C (109.9 F)
1974
42.2 C (108.0 F)
1975
42.8 C (109.0 F)
1976
45.0 C (113.0 F)
1977
41.1 C (106.0 F)
1978
41.1 C (106.0 F)
1979
41.1 C (106.0 F)
1980
43.3 C (109.9 F)
1981
38.3 C (100.9 F)
1982
39.4 C (102.9 F)
1983
42.8 C (109.0 F)
1984
41.1 C (106.0 F)
1985
41.1 C (106.0 F)
1986
38.9 C (102.0 F)
1987
43.3 C (109.9 F)
1988
44.4 C (111.9 F)
1989
44.4 C (111.9 F)
1990
38.9 C (102.0 F)
1991
42.8 C (109.0 F)
1992
37.8 C (100.0 F)
1993
36.1 C (97.0 F)
1994
37.8 C (100.0 F)
1995
38.3 C (100.9 F)
1996
36.7 C (98.1 F)
2000
42.2 C (108.0 F)
2003
41.1 C (106.0 F)
2004
37.8 C (100.0 F)
2005
41.1 C (106.0 F)
2006
45.0 C (113.0 F)
2007
42.2 C (108.0 F)
2008
37.2 C (99.0 F)
2009
37.2 C (99.0 F)
2010
39.4 C (102.9 F)
2011
38.9 C (102.0 F)
2012
42.2 C (108.0 F)
2013
37.8 C (100.0 F)
2014
39.4 C (102.9 F)
2015
38.9 C (102.0 F)
2016
42.2 C (108.0 F)
2017
40.6 C (105.1 F)
2018
37.8 C (100.0 F)
2019
37.2 C (99.0 F)
2020
4.4 C (39.9 F)
2021
33.9 C (93.0 F)
Coldest night (TNn)
The coldest night of the year at Harrold 12 SSW, 1963 to 2021. The record is -42.2 C (-44.0 F) in 1994, marked on the chart; the median year is -33.0 C (-27.5 F).
Coldest night (TNn) at Harrold 12 SSW by year
Year
Coldest night (TNn)
1963
-33.3 C (-27.9 F)
1964
-33.3 C (-27.9 F)
1965
-33.3 C (-27.9 F)
1966
-40.0 C (-40.0 F)
1967
-35.0 C (-31.0 F)
1968
-34.4 C (-29.9 F)
1969
-31.7 C (-25.1 F)
1970
-39.4 C (-38.9 F)
1971
-32.8 C (-27.0 F)
1972
-36.1 C (-33.0 F)
1973
-33.3 C (-27.9 F)
1974
-33.3 C (-27.9 F)
1975
-32.2 C (-26.0 F)
1976
-31.7 C (-25.1 F)
1977
-33.9 C (-29.0 F)
1978
-31.7 C (-25.1 F)
1979
-34.4 C (-29.9 F)
1980
-30.6 C (-23.1 F)
1981
-32.8 C (-27.0 F)
1982
-35.0 C (-31.0 F)
1983
-36.7 C (-34.1 F)
1984
-32.8 C (-27.0 F)
1985
-33.3 C (-27.9 F)
1986
-30.0 C (-22.0 F)
1987
-25.0 C (-13.0 F)
1988
-39.4 C (-38.9 F)
1989
-35.0 C (-31.0 F)
1990
-38.9 C (-38.0 F)
1991
-31.7 C (-25.1 F)
1992
-26.1 C (-15.0 F)
1993
-31.1 C (-24.0 F)
1994
-42.2 C (-44.0 F)
1995
-28.9 C (-20.0 F)
1996
-24.4 C (-11.9 F)
2000
-32.8 C (-27.0 F)
2003
-25.0 C (-13.0 F)
2004
-30.0 C (-22.0 F)
2005
-35.0 C (-31.0 F)
2006
-26.7 C (-16.1 F)
2007
-32.2 C (-26.0 F)
2008
-32.8 C (-27.0 F)
2009
-35.6 C (-32.1 F)
2010
-32.8 C (-27.0 F)
2011
-33.9 C (-29.0 F)
2012
-25.6 C (-14.1 F)
2013
-38.3 C (-36.9 F)
2014
-34.4 C (-29.9 F)
2015
-29.4 C (-20.9 F)
2016
-37.2 C (-35.0 F)
2017
-28.3 C (-18.9 F)
2018
-28.3 C (-18.9 F)
2019
-34.4 C (-29.9 F)
2020
-25.6 C (-14.1 F)
2021
-33.3 C (-27.9 F)
Wettest day (Rx1day)
The wettest day of the year at Harrold 12 SSW, 1963 to 2021. The record is 105.2 mm (4.1 in) in 1969, marked on the chart; the median year is 44.1 mm (1.7 in).
Wettest day (Rx1day) at Harrold 12 SSW by year
Year
Wettest day (Rx1day)
1963
20.8 mm (0.8 in)
1964
57.7 mm (2.3 in)
1965
24.4 mm (1.0 in)
1966
60.2 mm (2.4 in)
1967
28.4 mm (1.1 in)
1968
80.0 mm (3.1 in)
1969
105.2 mm (4.1 in)
1970
34.3 mm (1.4 in)
1971
49.5 mm (1.9 in)
1972
36.3 mm (1.4 in)
1973
62.0 mm (2.4 in)
1974
41.7 mm (1.6 in)
1975
42.7 mm (1.7 in)
1976
22.1 mm (0.9 in)
1977
76.2 mm (3.0 in)
1978
31.2 mm (1.2 in)
1979
45.2 mm (1.8 in)
1980
46.2 mm (1.8 in)
1981
49.8 mm (2.0 in)
1982
49.0 mm (1.9 in)
1983
61.5 mm (2.4 in)
1984
48.3 mm (1.9 in)
1985
30.5 mm (1.2 in)
1986
54.6 mm (2.1 in)
1987
31.5 mm (1.2 in)
1988
53.8 mm (2.1 in)
1989
38.1 mm (1.5 in)
1990
41.9 mm (1.6 in)
1991
49.8 mm (2.0 in)
1992
68.6 mm (2.7 in)
1993
31.8 mm (1.3 in)
1994
47.0 mm (1.9 in)
1995
40.9 mm (1.6 in)
1996
53.3 mm (2.1 in)
2000
41.9 mm (1.6 in)
2003
33.0 mm (1.3 in)
2004
63.8 mm (2.5 in)
2005
31.5 mm (1.2 in)
2006
26.4 mm (1.0 in)
2007
42.4 mm (1.7 in)
2008
49.0 mm (1.9 in)
2009
49.5 mm (1.9 in)
2010
52.3 mm (2.1 in)
2011
47.0 mm (1.9 in)
2012
40.9 mm (1.6 in)
2013
42.9 mm (1.7 in)
2014
29.2 mm (1.1 in)
2015
58.4 mm (2.3 in)
2016
41.9 mm (1.6 in)
2017
86.1 mm (3.4 in)
2018
45.7 mm (1.8 in)
2019
39.1 mm (1.5 in)
2020
0.0 mm (0.00 in)
2021
22.9 mm (0.9 in)
Wettest five days (Rx5day)
The wettest five days of the year at Harrold 12 SSW, 1963 to 2021. The record is 135.7 mm (5.3 in) in 1969, marked on the chart; the median year is 62.4 mm (2.5 in).
Wettest five days (Rx5day) at Harrold 12 SSW by year
Year
Wettest five days (Rx5day)
1963
41.1 mm (1.6 in)
1964
93.3 mm (3.7 in)
1965
40.6 mm (1.6 in)
1966
67.8 mm (2.7 in)
1967
57.9 mm (2.3 in)
1968
93.8 mm (3.7 in)
1969
135.7 mm (5.3 in)
1970
76.3 mm (3.0 in)
1971
60.2 mm (2.4 in)
1972
65.4 mm (2.6 in)
1973
64.8 mm (2.6 in)
1974
50.8 mm (2.0 in)
1975
42.7 mm (1.7 in)
1976
22.1 mm (0.9 in)
1977
76.2 mm (3.0 in)
1978
52.5 mm (2.1 in)
1979
47.3 mm (1.9 in)
1980
69.4 mm (2.7 in)
1981
52.2 mm (2.1 in)
1982
76.7 mm (3.0 in)
1983
71.1 mm (2.8 in)
1984
64.1 mm (2.5 in)
1985
51.1 mm (2.0 in)
1986
67.3 mm (2.6 in)
1987
45.6 mm (1.8 in)
1988
70.3 mm (2.8 in)
1989
50.3 mm (2.0 in)
1990
65.8 mm (2.6 in)
1991
76.2 mm (3.0 in)
1992
85.8 mm (3.4 in)
1993
49.6 mm (2.0 in)
1994
56.9 mm (2.2 in)
1995
60.9 mm (2.4 in)
1996
106.1 mm (4.2 in)
2000
41.9 mm (1.6 in)
2003
35.5 mm (1.4 in)
2004
63.8 mm (2.5 in)
2005
53.7 mm (2.1 in)
2006
41.7 mm (1.6 in)
2007
65.5 mm (2.6 in)
2008
68.5 mm (2.7 in)
2009
65.5 mm (2.6 in)
2010
92.4 mm (3.6 in)
2011
101.1 mm (4.0 in)
2012
60.9 mm (2.4 in)
2013
59.5 mm (2.3 in)
2014
40.7 mm (1.6 in)
2015
118.4 mm (4.7 in)
2016
68.6 mm (2.7 in)
2017
86.1 mm (3.4 in)
2018
54.2 mm (2.1 in)
2019
60.5 mm (2.4 in)
2020
0.0 mm (0.00 in)
2021
23.3 mm (0.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at Harrold 12 SSW, 1963 to 2021. The record is 105 days in 2012, marked on the chart; the median year is 36 days.
Longest dry spell (CDD) at Harrold 12 SSW by year
Year
Longest dry spell (CDD)
1963
36 days
1964
58 days
1965
36 days
1966
28 days
1967
49 days
1968
28 days
1969
19 days
1970
27 days
1971
28 days
1972
35 days
1973
19 days
1974
30 days
1975
25 days
1976
32 days
1977
34 days
1978
26 days
1979
54 days
1980
41 days
1981
46 days
1982
34 days
1983
64 days
1984
28 days
1985
25 days
1986
30 days
1987
26 days
1988
48 days
1989
30 days
1990
61 days
1991
39 days
1992
54 days
1993
87 days
1994
57 days
1995
51 days
1996
33 days
2000
21 days
2003
34 days
2004
60 days
2005
43 days
2006
47 days
2007
49 days
2008
55 days
2009
27 days
2010
53 days
2011
39 days
2012
105 days
2013
24 days
2014
42 days
2015
45 days
2016
44 days
2017
44 days
2018
39 days
2019
25 days
2020
28 days
2021
16 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
38 years with a frost
Across 38 years with a frost, the median last spring frost at Harrold 12 SSW falls on 18 May and the median first autumn frost on 20 September, which leaves a median of 125 days between them.
Fitted over all years, the growing season changes by +4.6 days per decade at this station.
Frost dates and growing season at Harrold 12 SSW
Measure
Median, all years
Earliest period
Recent period (1972 to 2016)
Recent against earliest
Fitted trend
Last spring frost
18 May
n/a
18 May
n/a
-1.0 days per decade
First autumn frost
20 September
n/a
21 September
n/a
+3.6 days per decade
Growing days
125 days
n/a
126 days
n/a
+4.6 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
40 years, 1964 to 2016
A day with at least 44.3 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 96.9 mm (3.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Harrold 12 SSW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
44.3 mm (1.7 in)
5 years
58.4 mm (2.3 in)
10 years
67.8 mm (2.7 in)
25 years
79.6 mm (3.1 in)
50 years
88.3 mm (3.5 in)
Longer than the 40 years of record
100 years
96.9 mm (3.8 in)
Longer than the 40 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, 40 years of values from 1964 to 2016.
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: 105.2 mm (4.1 in) in 1969; 80.0 mm (3.1 in) in 1968; 76.2 mm (3.0 in) in 1977.
Climate Twins
1994 to 2016 against 1961 to 1990
Over 1994 to 2016, Harrold 12 SSW had a mean temperature of 7.1 C (44.8 F) and 454.9 mm (17.9 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Bison (United States, 246 km away), Faith (United States, 191 km away) and Maurine 12SW (United States, 226 km away).
Climate twins of Harrold 12 SSW: stations whose 1961 to 1990 climate is closest to its 1994 to 2016 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 Harrold 12 SSW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Harrold 12 SSW 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.