Record envelope, standing records and threshold days for Andover (USC00390198), South Dakota, United States, with 69 years of record.
Key Facts for Andover
Andover (USC00390198) is a weather station in South Dakota, United States at 45.41 latitude and -97.91 longitude, 427 m (1,400 ft) above sea level.
The station reports from 1937 to 2005, 69 years of record.
1,464 records set at Andover still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Andover set a daily record high maximum temperature of 13.3 C (55.9 F) on 13 February 2005.
About the Station
Location: South Dakota, United States, 45.41 latitude, -97.91 longitude.
Elevation: 427 m (1,400 ft).
Period of record: 1937 to 2005, 69 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 Andover. 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 Andover, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
15.0 C (59.0 F)
-39.4 C (-38.9 F)
n/a
n/a
Feb
20.6 C (69.1 F)
-39.4 C (-38.9 F)
n/a
n/a
Mar
28.9 C (84.0 F)
-35.0 C (-31.0 F)
n/a
n/a
Apr
35.6 C (96.1 F)
-20.6 C (-5.1 F)
n/a
n/a
May
38.3 C (100.9 F)
-10.6 C (12.9 F)
n/a
n/a
Jun
41.1 C (106.0 F)
-2.2 C (28.0 F)
n/a
n/a
Jul
43.3 C (109.9 F)
1.7 C (35.1 F)
n/a
n/a
Aug
45.0 C (113.0 F)
0.6 C (33.1 F)
n/a
n/a
Sep
39.4 C (102.9 F)
-8.9 C (16.0 F)
n/a
n/a
Oct
36.7 C (98.1 F)
-16.1 C (3.0 F)
n/a
n/a
Nov
23.3 C (73.9 F)
-29.4 C (-20.9 F)
n/a
n/a
Dec
18.3 C (64.9 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 Andover still stand. 1959 holds the most, with 54.
Standing records at Andover by the year they were set
Year set
Standing records
1939
4
1940
6
1941
38
1942
45
1943
43
1944
42
1945
39
1946
37
1947
37
1948
45
1949
38
1950
49
1951
50
1952
36
1953
34
1954
31
1955
53
1956
35
1957
13
1958
52
1959
54
1960
35
1961
34
1962
37
1963
38
1964
34
1965
21
1966
28
1967
22
1968
30
1969
28
1970
26
1971
28
1972
21
1973
18
1974
24
1975
13
1997
27
1998
24
1999
25
2000
47
2001
28
2002
35
2003
21
2004
29
2005
10
Wettest Day of Each Month
Jun: 108.0 mm (4.3 in)
The wettest day on record for each calendar month at Andover. The most was 108.0 mm (4.3 in) on 10 June 1939.
Record daily precipitation for each month at Andover
Month
Record daily precipitation (mm)
Date
Jan
49.5 mm (1.9 in)
9 January 1939
Feb
40.6 mm (1.6 in)
3 February 1943
Mar
38.6 mm (1.5 in)
19 March 1968
Apr
71.6 mm (2.8 in)
17 April 1967
May
58.9 mm (2.3 in)
16 May 1962
Jun
108.0 mm (4.3 in)
10 June 1939
Jul
65.0 mm (2.6 in)
19 July 1969
Aug
67.3 mm (2.6 in)
17 August 1940
Sep
43.2 mm (1.7 in)
18 September 1946
Oct
61.0 mm (2.4 in)
17 October 1998
Nov
44.5 mm (1.8 in)
17 November 1952
Dec
27.4 mm (1.1 in)
11 December 1949
Period of Record Coverage
1939 to 2005
Complete yearUnder 90 percent of days
46 years of record at Andover, 1939 to 2005. 14 years have data for under 90 percent of days and are left out of rankings: 1939, 1940, 1964, 1965, 1968, 1969, 1970, 1971 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 29 complete years at Andover, 1941 to 2004. Blue stripes are years cooler than the station's own mean of 6.6 C (43.9 F); red stripes are warmer. The coolest year was 1950, at 4.4 C (39.9 F), and the warmest was 1998, at 8.3 C (46.9 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Andover as warming stripes, 1941 to 2004
Year
Annual mean temperature
Difference from the station mean
1941
7.7 C
+1.06 C
1942
6.5 C
-0.19 C
1943
5.8 C
-0.84 C
1944
6.7 C
+0.04 C
1945
5.6 C
-1.03 C
1946
6.7 C
+0.06 C
1947
6.1 C
-0.51 C
1948
6.4 C
-0.21 C
1949
6.9 C
+0.28 C
1950
4.4 C
-2.25 C
1951
4.5 C
-2.17 C
1952
6.6 C
-0.01 C
1953
7.3 C
+0.68 C
1954
7.1 C
+0.49 C
1955
6.6 C
-0.08 C
1956
6.4 C
-0.25 C
1957
6.7 C
+0.01 C
1958
7.0 C
+0.36 C
1959
6.9 C
+0.27 C
1963
7.1 C
+0.45 C
1966
5.2 C
-1.43 C
1997
6.1 C
-0.54 C
1998
8.3 C
+1.62 C
1999
8.1 C
+1.43 C
2000
7.0 C
+0.32 C
2001
7.2 C
+0.60 C
2002
7.5 C
+0.86 C
2003
7.0 C
+0.32 C
2004
7.2 C
+0.57 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
1937 to 2005
Yearly extremes at Andover: 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
38.9 C (102.0 F)
46
Coldest night (TNn)
-39.4 C (-38.9 F)
1943
-32.8 C (-27.0 F)
46
Wettest day (Rx1day)
108.0 mm (4.3 in)
1939
48.0 mm (1.9 in)
48
Wettest five days (Rx5day)
184.7 mm (7.3 in)
1966
69.2 mm (2.7 in)
48
Longest dry spell (CDD)
96 days
1999
34 days
48
Hottest day (TXx)
The hottest day of the year at Andover, 1937 to 2005. The record is 45.0 C (113.0 F) in 1965, marked on the chart; the median year is 38.9 C (102.0 F).
Hottest day (TXx) at Andover by year
Year
Hottest day (TXx)
1937
n/a
1938
n/a
1939
37.2 C (99.0 F)
1940
6.1 C (43.0 F)
1941
40.0 C (104.0 F)
1942
33.9 C (93.0 F)
1943
35.6 C (96.1 F)
1944
35.6 C (96.1 F)
1945
37.8 C (100.0 F)
1946
36.1 C (97.0 F)
1947
40.6 C (105.1 F)
1948
40.0 C (104.0 F)
1949
43.3 C (109.9 F)
1950
38.9 C (102.0 F)
1951
36.7 C (98.1 F)
1952
39.4 C (102.9 F)
1953
37.2 C (99.0 F)
1954
40.6 C (105.1 F)
1955
41.7 C (107.1 F)
1956
41.1 C (106.0 F)
1957
37.8 C (100.0 F)
1958
42.8 C (109.0 F)
1959
43.3 C (109.9 F)
1960
42.8 C (109.0 F)
1961
40.0 C (104.0 F)
1962
37.8 C (100.0 F)
1963
39.4 C (102.9 F)
1964
42.2 C (108.0 F)
1965
45.0 C (113.0 F)
1966
39.4 C (102.9 F)
1967
36.1 C (97.0 F)
1968
36.7 C (98.1 F)
1969
36.1 C (97.0 F)
1970
38.9 C (102.0 F)
1971
39.4 C (102.9 F)
1972
36.7 C (98.1 F)
1973
40.6 C (105.1 F)
1974
39.4 C (102.9 F)
1975
39.4 C (102.9 F)
1997
34.4 C (93.9 F)
1998
35.0 C (95.0 F)
1999
35.6 C (96.1 F)
2000
34.4 C (93.9 F)
2001
36.7 C (98.1 F)
2002
38.9 C (102.0 F)
2003
40.6 C (105.1 F)
2004
32.2 C (90.0 F)
2005
14.4 C (57.9 F)
Coldest night (TNn)
The coldest night of the year at Andover, 1937 to 2005. The record is -39.4 C (-38.9 F) in 1943, marked on the chart; the median year is -32.8 C (-27.0 F).
Coldest night (TNn) at Andover by year
Year
Coldest night (TNn)
1937
n/a
1938
n/a
1939
-12.2 C (10.0 F)
1940
-30.0 C (-22.0 F)
1941
-29.4 C (-20.9 F)
1942
-33.9 C (-29.0 F)
1943
-39.4 C (-38.9 F)
1944
-32.2 C (-26.0 F)
1945
-31.1 C (-24.0 F)
1946
-30.6 C (-23.1 F)
1947
-32.2 C (-26.0 F)
1948
-37.2 C (-35.0 F)
1949
-36.7 C (-34.1 F)
1950
-35.6 C (-32.1 F)
1951
-38.3 C (-36.9 F)
1952
-32.8 C (-27.0 F)
1953
-31.7 C (-25.1 F)
1954
-37.2 C (-35.0 F)
1955
-36.1 C (-33.0 F)
1956
-34.4 C (-29.9 F)
1957
-35.0 C (-31.0 F)
1958
-36.1 C (-33.0 F)
1959
-33.9 C (-29.0 F)
1960
-32.2 C (-26.0 F)
1961
-37.2 C (-35.0 F)
1962
-35.0 C (-31.0 F)
1963
-36.7 C (-34.1 F)
1964
-34.4 C (-29.9 F)
1965
-22.8 C (-9.0 F)
1966
-37.8 C (-36.0 F)
1967
-39.4 C (-38.9 F)
1968
-37.2 C (-35.0 F)
1969
-32.2 C (-26.0 F)
1970
-38.3 C (-36.9 F)
1971
-39.4 C (-38.9 F)
1972
-37.2 C (-35.0 F)
1973
-32.2 C (-26.0 F)
1974
-30.6 C (-23.1 F)
1975
-31.1 C (-24.0 F)
1997
-30.6 C (-23.1 F)
1998
-30.0 C (-22.0 F)
1999
-31.7 C (-25.1 F)
2000
-31.7 C (-25.1 F)
2001
-28.9 C (-20.0 F)
2002
-26.1 C (-15.0 F)
2003
-30.0 C (-22.0 F)
2004
-31.7 C (-25.1 F)
2005
-32.8 C (-27.0 F)
Wettest day (Rx1day)
The wettest day of the year at Andover, 1937 to 2005. The record is 108.0 mm (4.3 in) in 1939, marked on the chart; the median year is 48.0 mm (1.9 in).
Wettest day (Rx1day) at Andover by year
Year
Wettest day (Rx1day)
1937
54.9 mm (2.2 in)
1938
63.5 mm (2.5 in)
1939
108.0 mm (4.3 in)
1940
67.3 mm (2.6 in)
1941
43.9 mm (1.7 in)
1942
44.5 mm (1.8 in)
1943
52.1 mm (2.1 in)
1944
52.1 mm (2.1 in)
1945
33.8 mm (1.3 in)
1946
52.1 mm (2.1 in)
1947
69.1 mm (2.7 in)
1948
46.5 mm (1.8 in)
1949
64.8 mm (2.6 in)
1950
45.7 mm (1.8 in)
1951
52.3 mm (2.1 in)
1952
73.7 mm (2.9 in)
1953
41.9 mm (1.6 in)
1954
40.9 mm (1.6 in)
1955
38.6 mm (1.5 in)
1956
28.7 mm (1.1 in)
1957
38.6 mm (1.5 in)
1958
27.4 mm (1.1 in)
1959
29.2 mm (1.1 in)
1960
50.3 mm (2.0 in)
1961
57.2 mm (2.3 in)
1962
58.9 mm (2.3 in)
1963
31.8 mm (1.3 in)
1964
47.5 mm (1.9 in)
1965
38.1 mm (1.5 in)
1966
89.9 mm (3.5 in)
1967
71.6 mm (2.8 in)
1968
41.9 mm (1.6 in)
1969
65.0 mm (2.6 in)
1970
71.1 mm (2.8 in)
1971
56.9 mm (2.2 in)
1972
42.9 mm (1.7 in)
1973
48.5 mm (1.9 in)
1974
24.4 mm (1.0 in)
1975
48.8 mm (1.9 in)
1997
61.0 mm (2.4 in)
1998
61.0 mm (2.4 in)
1999
40.6 mm (1.6 in)
2000
30.5 mm (1.2 in)
2001
40.6 mm (1.6 in)
2002
31.5 mm (1.2 in)
2003
41.1 mm (1.6 in)
2004
64.3 mm (2.5 in)
2005
4.8 mm (0.19 in)
Wettest five days (Rx5day)
The wettest five days of the year at Andover, 1937 to 2005. The record is 184.7 mm (7.3 in) in 1966, marked on the chart; the median year is 69.2 mm (2.7 in).
Wettest five days (Rx5day) at Andover by year
Year
Wettest five days (Rx5day)
1937
73.2 mm (2.9 in)
1938
78.3 mm (3.1 in)
1939
113.1 mm (4.5 in)
1940
73.9 mm (2.9 in)
1941
53.0 mm (2.1 in)
1942
93.0 mm (3.7 in)
1943
83.5 mm (3.3 in)
1944
61.3 mm (2.4 in)
1945
57.4 mm (2.3 in)
1946
66.7 mm (2.6 in)
1947
76.2 mm (3.0 in)
1948
81.1 mm (3.2 in)
1949
84.7 mm (3.3 in)
1950
79.6 mm (3.1 in)
1951
94.5 mm (3.7 in)
1952
93.5 mm (3.7 in)
1953
67.1 mm (2.6 in)
1954
45.5 mm (1.8 in)
1955
49.8 mm (2.0 in)
1956
36.8 mm (1.4 in)
1957
69.9 mm (2.8 in)
1958
51.5 mm (2.0 in)
1959
47.0 mm (1.9 in)
1960
74.4 mm (2.9 in)
1961
69.2 mm (2.7 in)
1962
100.8 mm (4.0 in)
1963
61.0 mm (2.4 in)
1964
49.5 mm (1.9 in)
1965
69.8 mm (2.7 in)
1966
184.7 mm (7.3 in)
1967
97.0 mm (3.8 in)
1968
53.1 mm (2.1 in)
1969
106.6 mm (4.2 in)
1970
93.7 mm (3.7 in)
1971
56.9 mm (2.2 in)
1972
59.8 mm (2.4 in)
1973
49.8 mm (2.0 in)
1974
42.5 mm (1.7 in)
1975
64.3 mm (2.5 in)
1997
63.5 mm (2.5 in)
1998
86.4 mm (3.4 in)
1999
73.7 mm (2.9 in)
2000
44.2 mm (1.7 in)
2001
47.0 mm (1.9 in)
2002
48.0 mm (1.9 in)
2003
114.8 mm (4.5 in)
2004
69.1 mm (2.7 in)
2005
7.6 mm (0.30 in)
Longest dry spell (CDD)
The longest dry spell of the year at Andover, 1937 to 2005. The record is 96 days in 1999, marked on the chart; the median year is 34 days.
Longest dry spell (CDD) at Andover by year
Year
Longest dry spell (CDD)
1937
45 days
1938
34 days
1939
71 days
1940
29 days
1941
32 days
1942
38 days
1943
54 days
1944
33 days
1945
30 days
1946
22 days
1947
44 days
1948
27 days
1949
59 days
1950
41 days
1951
19 days
1952
56 days
1953
25 days
1954
30 days
1955
30 days
1956
39 days
1957
26 days
1958
32 days
1959
37 days
1960
28 days
1961
37 days
1962
22 days
1963
19 days
1964
36 days
1965
38 days
1966
36 days
1967
41 days
1968
55 days
1969
43 days
1970
32 days
1971
48 days
1972
28 days
1973
29 days
1974
31 days
1975
34 days
1997
26 days
1998
43 days
1999
96 days
2000
40 days
2001
37 days
2002
48 days
2003
27 days
2004
33 days
2005
22 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
29 years with a frost
Across 29 years with a frost, the median last spring frost at Andover falls on 20 May and the median first autumn frost on 20 September, which leaves a median of 126 days between them.
Fitted over all years, the growing season changes by +4.5 days per decade at this station.
Frost dates and growing season at Andover
Measure
Median, all years
Earliest period
Recent period (1941 to 2004)
Recent against earliest
Fitted trend
Last spring frost
20 May
n/a
20 May
n/a
-2.2 days per decade
First autumn frost
20 September
n/a
20 September
n/a
+2.2 days per decade
Growing days
126 days
n/a
126 days
n/a
+4.5 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
41 years, 1938 to 2004
A day with at least 49.1 mm (1.9 in) of rain is expected about once in 2 years. A day with at least 104.9 mm (4.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Andover: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
49.1 mm (1.9 in)
5 years
64.6 mm (2.5 in)
10 years
74.7 mm (2.9 in)
25 years
87.1 mm (3.4 in)
50 years
96.1 mm (3.8 in)
Longer than the 41 years of record
100 years
104.9 mm (4.1 in)
Longer than the 41 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, 41 years of values from 1938 to 2004.
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 1939; 89.9 mm (3.5 in) in 1966; 73.7 mm (2.9 in) in 1952.
Download the Data
Data for Andover standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Andover 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.