Record envelope, standing records and threshold days for Anamosa 1 WNW (USC00130213), Iowa, United States, with 75 years of record.
Key Facts for Anamosa 1 WNW
Anamosa 1 WNW (USC00130213) is a weather station in Iowa, United States at 42.11 latitude and -91.29 longitude, 245 m (805 ft) above sea level.
The station reports from 1937 to 2011, 75 years of record.
1,464 records set at Anamosa 1 WNW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Anamosa 1 WNW set a daily record snowfall of 10.2 cm (4.0 in) on 21 December 2010.
About the Station
Location: Iowa, United States, 42.11 latitude, -91.29 longitude.
Elevation: 245 m (805 ft).
Period of record: 1937 to 2011, 75 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 Anamosa 1 WNW. 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 Anamosa 1 WNW, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
18.9 C (66.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Feb
19.4 C (66.9 F)
-38.3 C (-36.9 F)
n/a
n/a
Mar
30.6 C (87.1 F)
-30.0 C (-22.0 F)
n/a
n/a
Apr
32.2 C (90.0 F)
-17.8 C (0.0 F)
n/a
n/a
May
33.9 C (93.0 F)
-6.7 C (19.9 F)
n/a
n/a
Jun
37.8 C (100.0 F)
0.6 C (33.1 F)
n/a
n/a
Jul
40.0 C (104.0 F)
3.9 C (39.0 F)
n/a
n/a
Aug
39.4 C (102.9 F)
2.8 C (37.0 F)
n/a
n/a
Sep
37.2 C (99.0 F)
-5.6 C (21.9 F)
n/a
n/a
Oct
33.9 C (93.0 F)
-12.2 C (10.0 F)
n/a
n/a
Nov
25.6 C (78.1 F)
-25.6 C (-14.1 F)
n/a
n/a
Dec
21.7 C (71.1 F)
-32.8 C (-27.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Anamosa 1 WNW still stand. 1963 holds the most, with 45.
Standing records at Anamosa 1 WNW by the year they were set
Year set
Standing records
1937
19
1938
16
1939
31
1940
37
1941
24
1942
36
1943
21
1944
14
1945
19
1946
13
1947
38
1948
16
1949
16
1950
31
1951
23
1952
19
1953
23
1954
21
1955
21
1956
13
1957
7
1958
17
1959
20
1960
21
1961
10
1962
22
1963
45
1964
17
1965
20
1966
18
1967
19
1968
19
1969
6
1970
11
1971
20
1972
17
1973
16
1974
27
1975
21
1976
29
1977
24
1978
12
1979
21
1980
1
1981
18
1982
21
1983
30
1984
21
1985
21
1986
22
1987
23
1988
32
1989
20
1990
26
1991
42
1992
26
1993
12
1994
16
1995
10
1996
17
1997
13
1998
23
1999
14
2000
23
2001
7
2002
20
2003
13
2004
17
2005
16
2006
24
2007
11
2008
13
2009
19
2010
3
All-Time Record Progression
12 new records
12 all-time records were set at Anamosa 1 WNW between 18 July 1968 and 7 February 2008. Each dot is a new record.
When Anamosa 1 WNW set new all-time records
Date
Kind
Detail
1968-07-18
Record high minimum temperature
Record high minimum temperature 26.1 C (79.0 F)
1973-04-09
Record daily snowfall
Record daily snowfall 21.6 cm (8.5 in)
1974-01-12
Record low minimum temperature
Record low minimum temperature -33.9 C (-29.0 F)
1975-02-24
Record daily snowfall
Record daily snowfall 22.9 cm (9.0 in)
1978-01-01
Record daily snowfall
Record daily snowfall 24.1 cm (9.5 in)
1990-12-03
Record daily snowfall
Record daily snowfall 25.4 cm (10.0 in)
1992-08-09
Record high minimum temperature
Record high minimum temperature 28.3 C (82.9 F)
1994-01-18
Record low maximum temperature
Record low maximum temperature -24.4 C (-11.9 F)
1994-01-19
Record low minimum temperature
Record low minimum temperature -34.4 C (-29.9 F)
1996-02-03
Record low minimum temperature
Record low minimum temperature -38.3 C (-36.9 F)
1999-07-03
Record daily precipitation
Record daily precipitation 165.6 mm (6.5 in)
2008-02-07
Record daily snowfall
Record daily snowfall 26.7 cm (10.5 in)
Wettest Day of Each Month
Jul: 165.6 mm (6.5 in)
The wettest day on record for each calendar month at Anamosa 1 WNW. The most was 165.6 mm (6.5 in) on 3 July 1999.
Record daily precipitation for each month at Anamosa 1 WNW
Month
Record daily precipitation (mm)
Date
Jan
48.0 mm (1.9 in)
12 January 1960
Feb
85.1 mm (3.4 in)
8 February 2001
Mar
63.0 mm (2.5 in)
25 March 1945
Apr
59.7 mm (2.4 in)
29 April 1974
May
111.3 mm (4.4 in)
29 May 1962
Jun
99.1 mm (3.9 in)
17 June 1990
Jul
165.6 mm (6.5 in)
3 July 1999
Aug
126.2 mm (5.0 in)
5 August 1968
Sep
135.9 mm (5.4 in)
8 September 1941
Oct
67.3 mm (2.6 in)
19 October 1984
Nov
81.3 mm (3.2 in)
17 November 1952
Dec
55.9 mm (2.2 in)
15 December 1971
Period of Record Coverage
1937 to 2010
Complete yearUnder 90 percent of days
74 years of record at Anamosa 1 WNW, 1937 to 2010. 3 years have data for under 90 percent of days and are left out of rankings: 1937, 1972, 1980.
Cooler than the station meanWarmer than the station mean
One stripe for each of 63 complete years at Anamosa 1 WNW, 1938 to 2010. Blue stripes are years cooler than the station's own mean of 8.8 C (47.8 F); red stripes are warmer. The coolest year was 2008, at 7.0 C (44.5 F), and the warmest was 1998, at 11.0 C (51.8 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Anamosa 1 WNW as warming stripes, 1938 to 2010
Year
Annual mean temperature
Difference from the station mean
1938
10.0 C
+1.21 C
1939
9.9 C
+1.13 C
1940
8.1 C
-0.65 C
1941
9.9 C
+1.13 C
1942
8.8 C
+0.05 C
1943
8.2 C
-0.58 C
1944
9.1 C
+0.31 C
1946
9.7 C
+0.95 C
1947
8.9 C
+0.08 C
1948
8.9 C
+0.09 C
1949
9.0 C
+0.25 C
1950
7.5 C
-1.31 C
1951
7.1 C
-1.68 C
1952
8.8 C
+0.02 C
1953
9.3 C
+0.52 C
1954
9.5 C
+0.76 C
1955
9.3 C
+0.47 C
1956
9.1 C
+0.30 C
1957
9.1 C
+0.34 C
1958
8.4 C
-0.34 C
1960
8.1 C
-0.64 C
1961
8.3 C
-0.51 C
1962
7.9 C
-0.91 C
1963
7.8 C
-0.96 C
1964
9.0 C
+0.22 C
1965
8.5 C
-0.32 C
1966
7.9 C
-0.93 C
1967
7.8 C
-0.96 C
1968
9.2 C
+0.42 C
1969
8.4 C
-0.39 C
1970
8.8 C
+0.05 C
1971
9.0 C
+0.20 C
1974
8.8 C
+0.04 C
1977
9.0 C
+0.19 C
1979
7.4 C
-1.42 C
1982
8.1 C
-0.70 C
1983
8.9 C
+0.09 C
1984
9.0 C
+0.23 C
1985
7.9 C
-0.85 C
1986
9.4 C
+0.63 C
1987
11.0 C
+2.20 C
1988
9.2 C
+0.44 C
1989
8.3 C
-0.50 C
1990
10.0 C
+1.24 C
1991
9.5 C
+0.70 C
1992
9.0 C
+0.18 C
1993
8.4 C
-0.41 C
1994
8.9 C
+0.10 C
1995
8.9 C
+0.14 C
1996
7.8 C
-0.96 C
1997
8.8 C
+0.01 C
1998
11.0 C
+2.21 C
1999
9.4 C
+0.62 C
2000
8.6 C
-0.15 C
2001
8.8 C
-0.03 C
2002
9.2 C
+0.39 C
2004
8.6 C
-0.15 C
2005
9.0 C
+0.20 C
2006
9.4 C
+0.62 C
2007
8.8 C
0.00 C
2008
7.0 C
-1.83 C
2009
7.6 C
-1.22 C
2010
8.6 C
-0.23 C
The fitted trend in annual mean temperature here over 1938 to 2010 is -0.01 C (-0.10 to 0.08) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.02 F (-0.19 to 0.14) per decade. The slope is a straight line fitted to 63 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Anamosa 1 WNW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.01 C (-0.10 to 0.08) per decade
-0.02 F (-0.19 to 0.14) per decade
1938 to 2010
63
Not clearly different from zero
Mean daily maximum
0.01 C (-0.09 to 0.11) per decade
0.02 F (-0.17 to 0.20) per decade
1938 to 2010
63
Not clearly different from zero
Mean daily minimum
-0.04 C (-0.14 to 0.07) per decade
-0.1 F (-0.3 to 0.1) per decade
1938 to 2010
63
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
1937 to 2011
Yearly extremes at Anamosa 1 WNW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
1940
35.0 C (95.0 F)
74
Coldest night (TNn)
-38.3 C (-36.9 F)
1996
-28.6 C (-19.5 F)
74
Wettest day (Rx1day)
165.6 mm (6.5 in)
1999
66.0 mm (2.6 in)
75
Wettest five days (Rx5day)
201.9 mm (7.9 in)
1993
95.3 mm (3.8 in)
75
Longest dry spell (CDD)
55 days
1952
22 days
75
Hottest day (TXx)
The hottest day of the year at Anamosa 1 WNW, 1937 to 2011. The record is 40.0 C (104.0 F) in 1940, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Anamosa 1 WNW by year
Year
Hottest day (TXx)
1937
37.2 C (99.0 F)
1938
33.9 C (93.0 F)
1939
37.2 C (99.0 F)
1940
40.0 C (104.0 F)
1941
37.2 C (99.0 F)
1942
34.4 C (93.9 F)
1943
34.4 C (93.9 F)
1944
35.6 C (96.1 F)
1945
35.0 C (95.0 F)
1946
34.4 C (93.9 F)
1947
39.4 C (102.9 F)
1948
36.7 C (98.1 F)
1949
35.0 C (95.0 F)
1950
31.7 C (89.1 F)
1951
33.9 C (93.0 F)
1952
33.9 C (93.0 F)
1953
36.1 C (97.0 F)
1954
36.1 C (97.0 F)
1955
37.8 C (100.0 F)
1956
36.7 C (98.1 F)
1957
35.0 C (95.0 F)
1958
33.9 C (93.0 F)
1959
33.3 C (91.9 F)
1960
34.4 C (93.9 F)
1961
33.3 C (91.9 F)
1962
33.9 C (93.0 F)
1963
37.2 C (99.0 F)
1964
35.0 C (95.0 F)
1965
35.6 C (96.1 F)
1966
36.1 C (97.0 F)
1967
32.8 C (91.0 F)
1968
34.4 C (93.9 F)
1969
33.3 C (91.9 F)
1970
33.9 C (93.0 F)
1971
34.4 C (93.9 F)
1972
34.4 C (93.9 F)
1973
35.0 C (95.0 F)
1974
36.1 C (97.0 F)
1975
34.4 C (93.9 F)
1976
35.6 C (96.1 F)
1977
38.3 C (100.9 F)
1978
35.0 C (95.0 F)
1979
34.4 C (93.9 F)
1980
20.0 C (68.0 F)
1981
35.0 C (95.0 F)
1982
35.0 C (95.0 F)
1983
37.8 C (100.0 F)
1984
36.1 C (97.0 F)
1985
36.1 C (97.0 F)
1986
35.6 C (96.1 F)
1987
38.9 C (102.0 F)
1988
38.9 C (102.0 F)
1989
36.7 C (98.1 F)
1990
35.6 C (96.1 F)
1991
35.0 C (95.0 F)
1992
33.3 C (91.9 F)
1993
32.8 C (91.0 F)
1994
33.9 C (93.0 F)
1995
37.2 C (99.0 F)
1996
34.4 C (93.9 F)
1997
35.6 C (96.1 F)
1998
35.6 C (96.1 F)
1999
36.7 C (98.1 F)
2000
35.6 C (96.1 F)
2001
34.4 C (93.9 F)
2002
35.0 C (95.0 F)
2003
36.7 C (98.1 F)
2004
32.8 C (91.0 F)
2005
36.1 C (97.0 F)
2006
35.6 C (96.1 F)
2007
32.8 C (91.0 F)
2008
32.8 C (91.0 F)
2009
34.4 C (93.9 F)
2010
33.9 C (93.0 F)
2011
n/a
Coldest night (TNn)
The coldest night of the year at Anamosa 1 WNW, 1937 to 2011. The record is -38.3 C (-36.9 F) in 1996, marked on the chart; the median year is -28.6 C (-19.5 F).
Coldest night (TNn) at Anamosa 1 WNW by year
Year
Coldest night (TNn)
1937
-20.0 C (-4.0 F)
1938
-22.8 C (-9.0 F)
1939
-21.1 C (-6.0 F)
1940
-29.4 C (-20.9 F)
1941
-24.4 C (-11.9 F)
1942
-30.6 C (-23.1 F)
1943
-28.9 C (-20.0 F)
1944
-28.9 C (-20.0 F)
1945
-26.1 C (-15.0 F)
1946
-26.1 C (-15.0 F)
1947
-32.2 C (-26.0 F)
1948
-25.6 C (-14.1 F)
1949
-30.0 C (-22.0 F)
1950
-32.8 C (-27.0 F)
1951
-33.3 C (-27.9 F)
1952
-25.6 C (-14.1 F)
1953
-27.8 C (-18.0 F)
1954
-27.2 C (-17.0 F)
1955
-26.7 C (-16.1 F)
1956
-28.9 C (-20.0 F)
1957
-30.6 C (-23.1 F)
1958
-28.3 C (-18.9 F)
1959
-29.4 C (-20.9 F)
1960
-30.6 C (-23.1 F)
1961
-26.1 C (-15.0 F)
1962
-31.7 C (-25.1 F)
1963
-32.8 C (-27.0 F)
1964
-22.8 C (-9.0 F)
1965
-27.8 C (-18.0 F)
1966
-32.2 C (-26.0 F)
1967
-31.7 C (-25.1 F)
1968
-28.3 C (-18.9 F)
1969
-26.1 C (-15.0 F)
1970
-32.2 C (-26.0 F)
1971
-32.2 C (-26.0 F)
1972
-30.0 C (-22.0 F)
1973
-25.0 C (-13.0 F)
1974
-33.9 C (-29.0 F)
1975
-26.1 C (-15.0 F)
1976
-28.3 C (-18.9 F)
1977
-32.2 C (-26.0 F)
1978
-28.9 C (-20.0 F)
1979
-33.9 C (-29.0 F)
1980
-22.2 C (-8.0 F)
1981
-27.8 C (-18.0 F)
1982
-32.8 C (-27.0 F)
1983
-30.0 C (-22.0 F)
1984
-31.7 C (-25.1 F)
1985
-32.8 C (-27.0 F)
1986
-30.0 C (-22.0 F)
1987
-22.2 C (-8.0 F)
1988
-28.9 C (-20.0 F)
1989
-32.8 C (-27.0 F)
1990
-25.0 C (-13.0 F)
1991
-30.0 C (-22.0 F)
1992
-26.1 C (-15.0 F)
1993
-27.8 C (-18.0 F)
1994
-34.4 C (-29.9 F)
1995
-21.7 C (-7.1 F)
1996
-38.3 C (-36.9 F)
1997
-26.7 C (-16.1 F)
1998
-20.0 C (-4.0 F)
1999
-34.4 C (-29.9 F)
2000
-32.8 C (-27.0 F)
2001
-25.6 C (-14.1 F)
2002
-25.6 C (-14.1 F)
2003
-23.3 C (-9.9 F)
2004
-25.6 C (-14.1 F)
2005
-27.2 C (-17.0 F)
2006
-26.7 C (-16.1 F)
2007
-27.8 C (-18.0 F)
2008
-29.4 C (-20.9 F)
2009
-38.3 C (-36.9 F)
2010
-27.8 C (-18.0 F)
2011
n/a
Wettest day (Rx1day)
The wettest day of the year at Anamosa 1 WNW, 1937 to 2011. The record is 165.6 mm (6.5 in) in 1999, marked on the chart; the median year is 66.0 mm (2.6 in).
Wettest day (Rx1day) at Anamosa 1 WNW by year
Year
Wettest day (Rx1day)
1937
48.3 mm (1.9 in)
1938
63.8 mm (2.5 in)
1939
131.8 mm (5.2 in)
1940
56.4 mm (2.2 in)
1941
135.9 mm (5.4 in)
1942
57.9 mm (2.3 in)
1943
41.9 mm (1.6 in)
1944
94.7 mm (3.7 in)
1945
76.5 mm (3.0 in)
1946
58.2 mm (2.3 in)
1947
85.9 mm (3.4 in)
1948
56.6 mm (2.2 in)
1949
40.6 mm (1.6 in)
1950
56.6 mm (2.2 in)
1951
71.9 mm (2.8 in)
1952
81.3 mm (3.2 in)
1953
54.4 mm (2.1 in)
1954
78.7 mm (3.1 in)
1955
57.7 mm (2.3 in)
1956
35.3 mm (1.4 in)
1957
78.2 mm (3.1 in)
1958
45.5 mm (1.8 in)
1959
69.6 mm (2.7 in)
1960
66.5 mm (2.6 in)
1961
116.1 mm (4.6 in)
1962
111.3 mm (4.4 in)
1963
128.3 mm (5.1 in)
1964
45.2 mm (1.8 in)
1965
58.2 mm (2.3 in)
1966
33.3 mm (1.3 in)
1967
103.6 mm (4.1 in)
1968
126.2 mm (5.0 in)
1969
59.4 mm (2.3 in)
1970
61.0 mm (2.4 in)
1971
61.0 mm (2.4 in)
1972
69.3 mm (2.7 in)
1973
50.3 mm (2.0 in)
1974
73.7 mm (2.9 in)
1975
46.2 mm (1.8 in)
1976
42.7 mm (1.7 in)
1977
88.4 mm (3.5 in)
1978
48.3 mm (1.9 in)
1979
42.9 mm (1.7 in)
1980
65.0 mm (2.6 in)
1981
50.5 mm (2.0 in)
1982
117.9 mm (4.6 in)
1983
35.8 mm (1.4 in)
1984
67.3 mm (2.6 in)
1985
52.6 mm (2.1 in)
1986
85.1 mm (3.4 in)
1987
101.6 mm (4.0 in)
1988
37.1 mm (1.5 in)
1989
39.4 mm (1.6 in)
1990
99.1 mm (3.9 in)
1991
67.8 mm (2.7 in)
1992
49.5 mm (1.9 in)
1993
101.6 mm (4.0 in)
1994
40.1 mm (1.6 in)
1995
40.6 mm (1.6 in)
1996
71.1 mm (2.8 in)
1997
62.0 mm (2.4 in)
1998
80.3 mm (3.2 in)
1999
165.6 mm (6.5 in)
2000
50.8 mm (2.0 in)
2001
85.1 mm (3.4 in)
2002
73.7 mm (2.9 in)
2003
85.1 mm (3.4 in)
2004
66.0 mm (2.6 in)
2005
69.9 mm (2.8 in)
2006
59.9 mm (2.4 in)
2007
71.4 mm (2.8 in)
2008
69.9 mm (2.8 in)
2009
105.4 mm (4.1 in)
2010
66.0 mm (2.6 in)
2011
22.4 mm (0.9 in)
Wettest five days (Rx5day)
The wettest five days of the year at Anamosa 1 WNW, 1937 to 2011. The record is 201.9 mm (7.9 in) in 1993, marked on the chart; the median year is 95.3 mm (3.8 in).
Wettest five days (Rx5day) at Anamosa 1 WNW by year
Year
Wettest five days (Rx5day)
1937
64.0 mm (2.5 in)
1938
83.6 mm (3.3 in)
1939
138.4 mm (5.4 in)
1940
79.8 mm (3.1 in)
1941
167.1 mm (6.6 in)
1942
81.3 mm (3.2 in)
1943
68.3 mm (2.7 in)
1944
145.8 mm (5.7 in)
1945
84.6 mm (3.3 in)
1946
106.5 mm (4.2 in)
1947
133.6 mm (5.3 in)
1948
70.1 mm (2.8 in)
1949
106.9 mm (4.2 in)
1950
77.5 mm (3.1 in)
1951
102.9 mm (4.1 in)
1952
96.5 mm (3.8 in)
1953
81.0 mm (3.2 in)
1954
112.5 mm (4.4 in)
1955
77.0 mm (3.0 in)
1956
94.0 mm (3.7 in)
1957
113.3 mm (4.5 in)
1958
72.4 mm (2.9 in)
1959
110.6 mm (4.4 in)
1960
112.3 mm (4.4 in)
1961
166.7 mm (6.6 in)
1962
121.5 mm (4.8 in)
1963
151.7 mm (6.0 in)
1964
85.8 mm (3.4 in)
1965
143.3 mm (5.6 in)
1966
91.5 mm (3.6 in)
1967
165.3 mm (6.5 in)
1968
131.1 mm (5.2 in)
1969
151.4 mm (6.0 in)
1970
102.4 mm (4.0 in)
1971
76.2 mm (3.0 in)
1972
81.7 mm (3.2 in)
1973
73.2 mm (2.9 in)
1974
114.7 mm (4.5 in)
1975
48.7 mm (1.9 in)
1976
58.9 mm (2.3 in)
1977
100.3 mm (3.9 in)
1978
66.3 mm (2.6 in)
1979
94.7 mm (3.7 in)
1980
78.2 mm (3.1 in)
1981
76.7 mm (3.0 in)
1982
146.9 mm (5.8 in)
1983
72.3 mm (2.8 in)
1984
109.9 mm (4.3 in)
1985
83.1 mm (3.3 in)
1986
130.6 mm (5.1 in)
1987
129.8 mm (5.1 in)
1988
57.7 mm (2.3 in)
1989
72.2 mm (2.8 in)
1990
127.8 mm (5.0 in)
1991
109.7 mm (4.3 in)
1992
97.8 mm (3.9 in)
1993
201.9 mm (7.9 in)
1994
71.8 mm (2.8 in)
1995
76.4 mm (3.0 in)
1996
106.4 mm (4.2 in)
1997
87.9 mm (3.5 in)
1998
98.5 mm (3.9 in)
1999
168.2 mm (6.6 in)
2000
86.1 mm (3.4 in)
2001
92.4 mm (3.6 in)
2002
95.3 mm (3.8 in)
2003
102.4 mm (4.0 in)
2004
80.3 mm (3.2 in)
2005
78.8 mm (3.1 in)
2006
66.0 mm (2.6 in)
2007
94.5 mm (3.7 in)
2008
156.2 mm (6.1 in)
2009
162.0 mm (6.4 in)
2010
100.3 mm (3.9 in)
2011
31.8 mm (1.3 in)
Longest dry spell (CDD)
The longest dry spell of the year at Anamosa 1 WNW, 1937 to 2011. The record is 55 days in 1952, marked on the chart; the median year is 22 days.
Longest dry spell (CDD) at Anamosa 1 WNW by year
Year
Longest dry spell (CDD)
1937
20 days
1938
22 days
1939
30 days
1940
21 days
1941
22 days
1942
37 days
1943
27 days
1944
25 days
1945
24 days
1946
22 days
1947
34 days
1948
40 days
1949
21 days
1950
29 days
1951
16 days
1952
55 days
1953
30 days
1954
23 days
1955
18 days
1956
19 days
1957
29 days
1958
26 days
1959
21 days
1960
17 days
1961
21 days
1962
20 days
1963
26 days
1964
36 days
1965
20 days
1966
25 days
1967
29 days
1968
30 days
1969
18 days
1970
22 days
1971
31 days
1972
22 days
1973
18 days
1974
15 days
1975
47 days
1976
26 days
1977
25 days
1978
21 days
1979
21 days
1980
22 days
1981
29 days
1982
18 days
1983
18 days
1984
27 days
1985
15 days
1986
22 days
1987
32 days
1988
38 days
1989
22 days
1990
13 days
1991
32 days
1992
27 days
1993
22 days
1994
23 days
1995
35 days
1996
22 days
1997
13 days
1998
19 days
1999
37 days
2000
19 days
2001
20 days
2002
50 days
2003
24 days
2004
18 days
2005
23 days
2006
19 days
2007
33 days
2008
14 days
2009
25 days
2010
20 days
2011
3 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
63 years with a frost
Across 63 years with a frost, the median last spring frost at Anamosa 1 WNW falls on 6 May and the median first autumn frost on 30 September, which leaves a median of 147 days between them.
In 1977 to 2010 the median growing season was 147 days. That is 3 days fewer than in 1938 to 1969.
Fitted over all years, the growing season changes by -0.7 days per decade at this station.
Frost dates and growing season at Anamosa 1 WNW
Measure
Median, all years
Earliest period (1938 to 1969)
Recent period (1977 to 2010)
Recent against earliest
Fitted trend
Last spring frost
6 May
5 May
8 May
3 days later
+0.5 days per decade
First autumn frost
30 September
29 September
2 October
3 days later
-0.3 days per decade
Growing days
147 days
150 days
147 days
3 days fewer
-0.7 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
66 years, 1939 to 2010
A day with at least 65.3 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 174.8 mm (6.9 in) of rain is expected about once in 100 years.
Rainfall return levels at Anamosa 1 WNW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
65.3 mm (2.6 in)
5 years
90.9 mm (3.6 in)
10 years
109.2 mm (4.3 in)
25 years
134.1 mm (5.3 in)
50 years
154.0 mm (6.1 in)
100 years
174.8 mm (6.9 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 1939 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: 165.6 mm (6.5 in) in 1999; 135.9 mm (5.4 in) in 1941; 131.8 mm (5.2 in) in 1939.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Anamosa 1 WNW, at 1968. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1968 ran 0.2 C (0.4 F) higher than in the years before (possible change).
Suspected changes in the annual mean temperature at Anamosa 1 WNW, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1968
+0.2
+0.4
possible
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.
Download the Data
Data for Anamosa 1 WNW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Anamosa 1 WNW 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.