Record envelope, standing records and threshold days for Norwich Exp Farm (USC00136119), Iowa, United States, with 34 years of record.
Key Facts for Norwich Exp Farm
Norwich Exp Farm (USC00136119) is a weather station in Iowa, United States at 40.75 latitude and -95.20 longitude, 345 m (1,132 ft) above sea level.
The station reports from 1937 to 1970, 34 years of record.
1,464 records set at Norwich Exp Farm still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Norwich Exp Farm set a daily record low minimum temperature of -14.4 C (6.1 F) on 28 March 1970.
About the Station
Location: Iowa, United States, 40.75 latitude, -95.20 longitude.
Elevation: 345 m (1,132 ft).
Period of record: 1937 to 1970, 34 years.
Eligible elements: tmax, tmin, prcp, snow.
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 Norwich Exp Farm. 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 Norwich Exp Farm, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
18.3 C (64.9 F)
-30.6 C (-23.1 F)
n/a
n/a
Feb
22.2 C (72.0 F)
-29.4 C (-20.9 F)
n/a
n/a
Mar
30.6 C (87.1 F)
-28.3 C (-18.9 F)
n/a
n/a
Apr
32.8 C (91.0 F)
-9.4 C (15.1 F)
n/a
n/a
May
36.1 C (97.0 F)
-2.8 C (27.0 F)
n/a
n/a
Jun
39.4 C (102.9 F)
2.8 C (37.0 F)
n/a
n/a
Jul
40.6 C (105.1 F)
8.9 C (48.0 F)
n/a
n/a
Aug
38.3 C (100.9 F)
4.4 C (39.9 F)
n/a
n/a
Sep
38.9 C (102.0 F)
-3.3 C (26.1 F)
n/a
n/a
Oct
33.9 C (93.0 F)
-9.4 C (15.1 F)
n/a
n/a
Nov
26.1 C (79.0 F)
-23.9 C (-11.0 F)
n/a
n/a
Dec
22.8 C (73.0 F)
-27.2 C (-17.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Norwich Exp Farm still stand. 1955 holds the most, with 62.
Standing records at Norwich Exp Farm by the year they were set
Year set
Standing records
1937
5
1938
61
1939
55
1940
43
1941
48
1942
57
1943
47
1944
59
1945
50
1946
50
1947
51
1948
39
1949
25
1950
56
1951
49
1952
50
1953
35
1954
56
1955
62
1956
48
1957
31
1958
38
1959
27
1960
38
1961
31
1962
51
1963
57
1964
47
1965
36
1966
46
1967
43
1968
39
1969
21
1970
13
Wettest Day of Each Month
Jul: 121.4 mm (4.8 in)
The wettest day on record for each calendar month at Norwich Exp Farm. The most was 121.4 mm (4.8 in) on 30 July 1958.
Record daily precipitation for each month at Norwich Exp Farm
Month
Record daily precipitation (mm)
Date
Jan
26.9 mm (1.1 in)
1 January 1942
Feb
40.9 mm (1.6 in)
21 February 1945
Mar
41.4 mm (1.6 in)
26 March 1959
Apr
54.6 mm (2.1 in)
26 April 1969
May
97.8 mm (3.9 in)
9 May 1950
Jun
91.9 mm (3.6 in)
9 June 1941
Jul
121.4 mm (4.8 in)
30 July 1958
Aug
75.2 mm (3.0 in)
29 August 1960
Sep
111.0 mm (4.4 in)
15 September 1941
Oct
98.3 mm (3.9 in)
5 October 1954
Nov
80.5 mm (3.2 in)
17 November 1952
Dec
33.8 mm (1.3 in)
19 December 1968
Period of Record Coverage
1937 to 1970
Complete yearUnder 90 percent of days
34 years of record at Norwich Exp Farm, 1937 to 1970. 2 years have data for under 90 percent of days and are left out of rankings: 1937, 1970.
Cooler than the station meanWarmer than the station mean
One stripe for each of 28 complete years at Norwich Exp Farm, 1938 to 1969. Blue stripes are years cooler than the station's own mean of 10.5 C (50.9 F); red stripes are warmer. The coolest year was 1951, at 9.1 C (48.3 F), and the warmest was 1954, at 12.2 C (53.9 F). The strongest colour marks a difference of 1.7 C (3.1 F).
Annual mean temperature at Norwich Exp Farm as warming stripes, 1938 to 1969
Year
Annual mean temperature
Difference from the station mean
1938
11.7 C
+1.22 C
1939
11.7 C
+1.22 C
1940
9.8 C
-0.74 C
1941
11.6 C
+1.11 C
1942
10.4 C
-0.11 C
1943
10.1 C
-0.40 C
1944
10.3 C
-0.25 C
1945
9.6 C
-0.90 C
1946
11.5 C
+1.01 C
1947
10.7 C
+0.20 C
1949
10.2 C
-0.33 C
1950
9.4 C
-1.14 C
1951
9.1 C
-1.43 C
1952
10.7 C
+0.24 C
1953
11.8 C
+1.32 C
1954
12.2 C
+1.67 C
1958
10.1 C
-0.38 C
1959
10.3 C
-0.22 C
1960
9.7 C
-0.78 C
1961
9.8 C
-0.66 C
1962
10.2 C
-0.30 C
1963
10.9 C
+0.38 C
1964
10.8 C
+0.34 C
1965
10.2 C
-0.34 C
1966
9.9 C
-0.58 C
1967
10.2 C
-0.32 C
1968
10.9 C
+0.42 C
1969
10.3 C
-0.16 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 1970
Yearly extremes at Norwich Exp Farm: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.6 C (105.1 F)
1954
36.7 C (98.1 F)
34
Coldest night (TNn)
-30.6 C (-23.1 F)
1947
-26.1 C (-15.0 F)
34
Wettest day (Rx1day)
121.4 mm (4.8 in)
1958
58.8 mm (2.3 in)
34
Wettest five days (Rx5day)
184.9 mm (7.3 in)
1958
93.6 mm (3.7 in)
34
Longest dry spell (CDD)
54 days
1952
27 days
34
Hottest day (TXx)
The hottest day of the year at Norwich Exp Farm, 1937 to 1970. The record is 40.6 C (105.1 F) in 1954, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Norwich Exp Farm by year
Year
Hottest day (TXx)
1937
9.4 C (48.9 F)
1938
38.9 C (102.0 F)
1939
38.9 C (102.0 F)
1940
39.4 C (102.9 F)
1941
38.3 C (100.9 F)
1942
36.7 C (98.1 F)
1943
35.6 C (96.1 F)
1944
36.7 C (98.1 F)
1945
36.7 C (98.1 F)
1946
39.4 C (102.9 F)
1947
38.3 C (100.9 F)
1948
36.1 C (97.0 F)
1949
35.0 C (95.0 F)
1950
36.1 C (97.0 F)
1951
34.4 C (93.9 F)
1952
37.8 C (100.0 F)
1953
38.9 C (102.0 F)
1954
40.6 C (105.1 F)
1955
39.4 C (102.9 F)
1956
40.0 C (104.0 F)
1957
37.8 C (100.0 F)
1958
35.0 C (95.0 F)
1959
34.4 C (93.9 F)
1960
35.0 C (95.0 F)
1961
34.4 C (93.9 F)
1962
35.0 C (95.0 F)
1963
37.2 C (99.0 F)
1964
37.8 C (100.0 F)
1965
33.9 C (93.0 F)
1966
37.8 C (100.0 F)
1967
36.1 C (97.0 F)
1968
35.0 C (95.0 F)
1969
35.6 C (96.1 F)
1970
20.6 C (69.1 F)
Coldest night (TNn)
The coldest night of the year at Norwich Exp Farm, 1937 to 1970. The record is -30.6 C (-23.1 F) in 1947, marked on the chart; the median year is -26.1 C (-15.0 F).
Coldest night (TNn) at Norwich Exp Farm by year
Year
Coldest night (TNn)
1937
-20.0 C (-4.0 F)
1938
-24.4 C (-11.9 F)
1939
-22.8 C (-9.0 F)
1940
-30.0 C (-22.0 F)
1941
-16.7 C (1.9 F)
1942
-26.1 C (-15.0 F)
1943
-28.9 C (-20.0 F)
1944
-28.9 C (-20.0 F)
1945
-27.2 C (-17.0 F)
1946
-23.9 C (-11.0 F)
1947
-30.6 C (-23.1 F)
1948
-28.9 C (-20.0 F)
1949
-24.4 C (-11.9 F)
1950
-23.3 C (-9.9 F)
1951
-26.7 C (-16.1 F)
1952
-20.0 C (-4.0 F)
1953
-23.3 C (-9.9 F)
1954
-24.4 C (-11.9 F)
1955
-26.1 C (-15.0 F)
1956
-23.9 C (-11.0 F)
1957
-25.6 C (-14.1 F)
1958
-29.4 C (-20.9 F)
1959
-26.7 C (-16.1 F)
1960
-28.3 C (-18.9 F)
1961
-26.1 C (-15.0 F)
1962
-28.3 C (-18.9 F)
1963
-27.2 C (-17.0 F)
1964
-23.9 C (-11.0 F)
1965
-27.8 C (-18.0 F)
1966
-28.3 C (-18.9 F)
1967
-21.7 C (-7.1 F)
1968
-28.9 C (-20.0 F)
1969
-24.4 C (-11.9 F)
1970
-26.7 C (-16.1 F)
Wettest day (Rx1day)
The wettest day of the year at Norwich Exp Farm, 1937 to 1970. The record is 121.4 mm (4.8 in) in 1958, marked on the chart; the median year is 58.8 mm (2.3 in).
Wettest day (Rx1day) at Norwich Exp Farm by year
Year
Wettest day (Rx1day)
1937
3.3 mm (0.13 in)
1938
57.4 mm (2.3 in)
1939
55.1 mm (2.2 in)
1940
47.5 mm (1.9 in)
1941
111.0 mm (4.4 in)
1942
67.8 mm (2.7 in)
1943
90.9 mm (3.6 in)
1944
64.3 mm (2.5 in)
1945
59.2 mm (2.3 in)
1946
53.3 mm (2.1 in)
1947
76.2 mm (3.0 in)
1948
42.4 mm (1.7 in)
1949
72.4 mm (2.9 in)
1950
97.8 mm (3.9 in)
1951
56.4 mm (2.2 in)
1952
80.5 mm (3.2 in)
1953
52.3 mm (2.1 in)
1954
98.3 mm (3.9 in)
1955
51.6 mm (2.0 in)
1956
35.3 mm (1.4 in)
1957
59.7 mm (2.4 in)
1958
121.4 mm (4.8 in)
1959
86.9 mm (3.4 in)
1960
75.2 mm (3.0 in)
1961
84.6 mm (3.3 in)
1962
61.7 mm (2.4 in)
1963
52.6 mm (2.1 in)
1964
58.4 mm (2.3 in)
1965
49.0 mm (1.9 in)
1966
40.6 mm (1.6 in)
1967
36.6 mm (1.4 in)
1968
49.8 mm (2.0 in)
1969
83.8 mm (3.3 in)
1970
11.2 mm (0.4 in)
Wettest five days (Rx5day)
The wettest five days of the year at Norwich Exp Farm, 1937 to 1970. The record is 184.9 mm (7.3 in) in 1958, marked on the chart; the median year is 93.6 mm (3.7 in).
Wettest five days (Rx5day) at Norwich Exp Farm by year
Year
Wettest five days (Rx5day)
1937
3.3 mm (0.13 in)
1938
73.7 mm (2.9 in)
1939
93.2 mm (3.7 in)
1940
104.9 mm (4.1 in)
1941
127.0 mm (5.0 in)
1942
99.3 mm (3.9 in)
1943
123.8 mm (4.9 in)
1944
87.6 mm (3.4 in)
1945
70.6 mm (2.8 in)
1946
104.1 mm (4.1 in)
1947
85.6 mm (3.4 in)
1948
50.8 mm (2.0 in)
1949
92.2 mm (3.6 in)
1950
112.2 mm (4.4 in)
1951
77.2 mm (3.0 in)
1952
83.8 mm (3.3 in)
1953
107.1 mm (4.2 in)
1954
107.7 mm (4.2 in)
1955
81.3 mm (3.2 in)
1956
70.2 mm (2.8 in)
1957
93.9 mm (3.7 in)
1958
184.9 mm (7.3 in)
1959
108.2 mm (4.3 in)
1960
109.0 mm (4.3 in)
1961
141.0 mm (5.6 in)
1962
104.8 mm (4.1 in)
1963
69.6 mm (2.7 in)
1964
81.6 mm (3.2 in)
1965
113.8 mm (4.5 in)
1966
67.0 mm (2.6 in)
1967
102.9 mm (4.1 in)
1968
59.0 mm (2.3 in)
1969
114.3 mm (4.5 in)
1970
20.6 mm (0.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Norwich Exp Farm, 1937 to 1970. The record is 54 days in 1952, marked on the chart; the median year is 27 days.
Longest dry spell (CDD) at Norwich Exp Farm by year
Year
Longest dry spell (CDD)
1937
12 days
1938
27 days
1939
51 days
1940
20 days
1941
19 days
1942
31 days
1943
27 days
1944
22 days
1945
25 days
1946
45 days
1947
28 days
1948
22 days
1949
28 days
1950
26 days
1951
18 days
1952
54 days
1953
27 days
1954
49 days
1955
34 days
1956
48 days
1957
38 days
1958
32 days
1959
28 days
1960
22 days
1961
23 days
1962
27 days
1963
29 days
1964
24 days
1965
22 days
1966
26 days
1967
29 days
1968
43 days
1969
24 days
1970
42 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
28 years with a frost
Across 28 years with a frost, the median last spring frost at Norwich Exp Farm falls on 28 April and the median first autumn frost on 10 October, which leaves a median of 162 days between them.
Fitted over all years, the growing season changes by -2.4 days per decade at this station.
Frost dates and growing season at Norwich Exp Farm
Measure
Median, all years
Earliest period
Recent period (1938 to 1969)
Recent against earliest
Fitted trend
Last spring frost
28 April
n/a
28 April
n/a
+0.2 days per decade
First autumn frost
10 October
n/a
10 October
n/a
-2.3 days per decade
Growing days
162 days
n/a
162 days
n/a
-2.4 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
32 years, 1938 to 1969
A day with at least 62.5 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 140.3 mm (5.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Norwich Exp Farm: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
62.5 mm (2.5 in)
5 years
82.3 mm (3.2 in)
10 years
95.8 mm (3.8 in)
25 years
113.4 mm (4.5 in)
50 years
126.8 mm (5.0 in)
Longer than the 32 years of record
100 years
140.3 mm (5.5 in)
Longer than the 32 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, 32 years of values from 1938 to 1969.
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: 121.4 mm (4.8 in) in 1958; 111.0 mm (4.4 in) in 1941; 98.3 mm (3.9 in) in 1954.
Download the Data
Data for Norwich Exp Farm standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Norwich Exp Farm 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.