Record envelope, standing records and threshold days for Norwalk (USC00065892), Connecticut, United States, with 64 years of record.
Key Facts for Norwalk
Norwalk (USC00065892) is a weather station in Connecticut, United States at 41.13 latitude and -73.45 longitude, 37 m (121 ft) above sea level.
The station reports from 1893 to 1956, 64 years of record.
1,464 records set at Norwalk still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Norwalk tied a daily record snowfall of 5.1 cm (2.0 in) on 8 April 1956.
About the Station
Location: Connecticut, United States, 41.13 latitude, -73.45 longitude.
Elevation: 37 m (121 ft).
Period of record: 1893 to 1956, 64 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 Norwalk. 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 Norwalk, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
21.1 C (70.0 F)
-30.0 C (-22.0 F)
n/a
n/a
Feb
21.1 C (70.0 F)
-28.9 C (-20.0 F)
n/a
n/a
Mar
30.6 C (87.1 F)
-21.1 C (-6.0 F)
n/a
n/a
Apr
33.3 C (91.9 F)
-12.8 C (9.0 F)
n/a
n/a
May
35.6 C (96.1 F)
-4.4 C (24.1 F)
n/a
n/a
Jun
37.8 C (100.0 F)
0.6 C (33.1 F)
n/a
n/a
Jul
38.9 C (102.0 F)
5.6 C (42.1 F)
n/a
n/a
Aug
40.0 C (104.0 F)
1.1 C (34.0 F)
n/a
n/a
Sep
38.9 C (102.0 F)
-2.2 C (28.0 F)
n/a
n/a
Oct
32.2 C (90.0 F)
-8.9 C (16.0 F)
n/a
n/a
Nov
28.3 C (82.9 F)
-20.0 C (-4.0 F)
n/a
n/a
Dec
21.7 C (71.1 F)
-26.7 C (-16.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Norwalk still stand. 1895 holds the most, with 43.
Standing records at Norwalk by the year they were set
Year set
Standing records
1893
27
1894
23
1895
43
1896
43
1897
19
1898
25
1899
35
1900
23
1901
29
1902
16
1903
30
1904
29
1905
16
1906
17
1907
24
1908
17
1909
22
1910
18
1911
22
1912
16
1913
23
1914
29
1915
21
1916
26
1917
28
1918
23
1919
23
1920
9
1921
19
1922
10
1923
25
1924
15
1925
26
1926
26
1927
13
1928
16
1929
26
1930
26
1931
28
1932
19
1933
30
1934
28
1935
23
1936
20
1937
13
1938
30
1939
18
1940
30
1941
20
1942
23
1943
25
1944
20
1945
31
1946
16
1947
23
1948
26
1949
34
1950
29
1951
19
1952
16
1953
22
1954
23
1955
15
1956
5
All-Time Record Progression
4 new records
4 all-time records were set at Norwalk between 21 July 1930 and 16 October 1955. Each dot is a new record.
When Norwalk set new all-time records
Date
Kind
Detail
1930-07-21
Record high maximum temperature
Record high maximum temperature 38.3 C (100.9 F)
1944-08-11
Record high maximum temperature
Record high maximum temperature 39.4 C (102.9 F)
1948-08-26
Record high maximum temperature
Record high maximum temperature 40.0 C (104.0 F)
1955-10-16
Record daily precipitation
Record daily precipitation 208.3 mm (8.2 in)
Wettest Day of Each Month
Oct: 208.3 mm (8.2 in)
The wettest day on record for each calendar month at Norwalk. The most was 208.3 mm (8.2 in) on 16 October 1955.
Record daily precipitation for each month at Norwalk
Month
Record daily precipitation (mm)
Date
Jan
61.5 mm (2.4 in)
7 January 1910
Feb
74.4 mm (2.9 in)
6 February 1896
Mar
145.3 mm (5.7 in)
1 March 1914
Apr
109.5 mm (4.3 in)
15 April 1909
May
105.2 mm (4.1 in)
27 May 1946
Jun
102.1 mm (4.0 in)
13 June 1936
Jul
133.4 mm (5.3 in)
23 July 1953
Aug
123.2 mm (4.9 in)
4 August 1915
Sep
123.4 mm (4.9 in)
30 September 1920
Oct
208.3 mm (8.2 in)
16 October 1955
Nov
91.9 mm (3.6 in)
26 November 1900
Dec
84.1 mm (3.3 in)
31 December 1901
Period of Record Coverage
1893 to 1956
Complete yearUnder 90 percent of days
64 years of record at Norwalk, 1893 to 1956. 1 years have data for under 90 percent of days and are left out of rankings: 1956.
Cooler than the station meanWarmer than the station mean
One stripe for each of 60 complete years at Norwalk, 1893 to 1954. Blue stripes are years cooler than the station's own mean of 9.8 C (49.7 F); red stripes are warmer. The coolest year was 1904, at 7.9 C (46.2 F), and the warmest was 1953, at 11.4 C (52.5 F). The strongest colour marks a difference of 2.0 C (3.6 F).
Annual mean temperature at Norwalk as warming stripes, 1893 to 1954
Year
Annual mean temperature
Difference from the station mean
1893
8.3 C
-1.57 C
1894
9.5 C
-0.28 C
1895
8.9 C
-0.95 C
1896
9.2 C
-0.66 C
1897
9.5 C
-0.36 C
1899
9.1 C
-0.75 C
1900
10.5 C
+0.65 C
1901
9.3 C
-0.49 C
1902
9.5 C
-0.34 C
1903
9.4 C
-0.47 C
1904
7.9 C
-1.93 C
1905
9.0 C
-0.86 C
1906
9.9 C
+0.03 C
1907
8.5 C
-1.35 C
1908
9.8 C
-0.03 C
1909
9.4 C
-0.43 C
1910
9.7 C
-0.09 C
1911
9.8 C
+0.00 C
1912
9.4 C
-0.38 C
1913
10.8 C
+1.00 C
1914
9.1 C
-0.68 C
1915
9.8 C
+0.00 C
1916
9.0 C
-0.82 C
1917
8.3 C
-1.53 C
1919
10.2 C
+0.42 C
1920
9.4 C
-0.46 C
1921
10.9 C
+1.04 C
1922
10.1 C
+0.29 C
1923
9.6 C
-0.18 C
1924
9.2 C
-0.66 C
1925
9.9 C
+0.07 C
1926
8.7 C
-1.10 C
1927
9.8 C
+0.00 C
1928
10.0 C
+0.13 C
1929
10.0 C
+0.21 C
1930
10.4 C
+0.57 C
1931
11.2 C
+1.37 C
1932
10.9 C
+1.04 C
1933
10.6 C
+0.79 C
1934
9.8 C
-0.01 C
1935
9.9 C
+0.07 C
1936
10.1 C
+0.29 C
1937
10.7 C
+0.85 C
1938
10.8 C
+0.96 C
1939
9.9 C
+0.08 C
1940
8.7 C
-1.14 C
1941
10.2 C
+0.39 C
1942
10.1 C
+0.28 C
1943
9.8 C
-0.02 C
1944
10.2 C
+0.41 C
1945
10.2 C
+0.38 C
1946
10.8 C
+0.99 C
1947
10.1 C
+0.28 C
1948
9.6 C
-0.20 C
1949
11.2 C
+1.34 C
1950
9.6 C
-0.20 C
1951
10.6 C
+0.74 C
1952
10.7 C
+0.89 C
1953
11.4 C
+1.56 C
1954
10.4 C
+0.60 C
The annual mean temperature here has risen by 0.2 C (0.2 to 0.3) per decade over 1893 to 1954. In Fahrenheit: 0.4 F (0.3 to 0.6) per decade. The slope is a straight line fitted to 60 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Norwalk
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.2 C (0.2 to 0.3) per decade
0.4 F (0.3 to 0.6) per decade
1893 to 1954
60
Rise
Mean daily maximum
0.3 C (0.2 to 0.4) per decade
0.6 F (0.4 to 0.8) per decade
1893 to 1954
60
Rise
Mean daily minimum
0.2 C (0.1 to 0.3) per decade
0.3 F (0.1 to 0.5) per decade
1893 to 1954
60
Rise
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
1893 to 1956
Yearly extremes at Norwalk: 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)
1948
36.1 C (97.0 F)
64
Coldest night (TNn)
-30.0 C (-22.0 F)
1904
-21.1 C (-6.0 F)
64
Wettest day (Rx1day)
208.3 mm (8.2 in)
1955
79.5 mm (3.1 in)
64
Wettest five days (Rx5day)
329.7 mm (13.0 in)
1955
99.3 mm (3.9 in)
64
Longest dry spell (CDD)
44 days
1924
17 days
64
Hottest day (TXx)
The hottest day of the year at Norwalk, 1893 to 1956. The record is 40.0 C (104.0 F) in 1948, marked on the chart; the median year is 36.1 C (97.0 F).
Hottest day (TXx) at Norwalk by year
Year
Hottest day (TXx)
1893
35.6 C (96.1 F)
1894
35.6 C (96.1 F)
1895
35.6 C (96.1 F)
1896
34.4 C (93.9 F)
1897
33.3 C (91.9 F)
1898
36.7 C (98.1 F)
1899
36.1 C (97.0 F)
1900
37.2 C (99.0 F)
1901
37.8 C (100.0 F)
1902
34.4 C (93.9 F)
1903
36.1 C (97.0 F)
1904
36.7 C (98.1 F)
1905
36.7 C (98.1 F)
1906
33.3 C (91.9 F)
1907
33.3 C (91.9 F)
1908
36.7 C (98.1 F)
1909
35.6 C (96.1 F)
1910
34.4 C (93.9 F)
1911
37.8 C (100.0 F)
1912
36.7 C (98.1 F)
1913
36.1 C (97.0 F)
1914
33.9 C (93.0 F)
1915
33.3 C (91.9 F)
1916
33.3 C (91.9 F)
1917
37.2 C (99.0 F)
1918
36.1 C (97.0 F)
1919
37.2 C (99.0 F)
1920
33.9 C (93.0 F)
1921
35.6 C (96.1 F)
1922
33.3 C (91.9 F)
1923
37.8 C (100.0 F)
1924
36.1 C (97.0 F)
1925
37.2 C (99.0 F)
1926
37.8 C (100.0 F)
1927
33.9 C (93.0 F)
1928
34.4 C (93.9 F)
1929
36.7 C (98.1 F)
1930
38.3 C (100.9 F)
1931
36.7 C (98.1 F)
1932
35.0 C (95.0 F)
1933
36.7 C (98.1 F)
1934
37.2 C (99.0 F)
1935
35.6 C (96.1 F)
1936
37.8 C (100.0 F)
1937
37.2 C (99.0 F)
1938
35.0 C (95.0 F)
1939
34.4 C (93.9 F)
1940
35.0 C (95.0 F)
1941
35.0 C (95.0 F)
1942
35.0 C (95.0 F)
1943
36.1 C (97.0 F)
1944
39.4 C (102.9 F)
1945
36.7 C (98.1 F)
1946
34.4 C (93.9 F)
1947
36.1 C (97.0 F)
1948
40.0 C (104.0 F)
1949
38.9 C (102.0 F)
1950
33.9 C (93.0 F)
1951
33.9 C (93.0 F)
1952
37.2 C (99.0 F)
1953
38.9 C (102.0 F)
1954
36.1 C (97.0 F)
1955
36.1 C (97.0 F)
1956
18.3 C (64.9 F)
Coldest night (TNn)
The coldest night of the year at Norwalk, 1893 to 1956. The record is -30.0 C (-22.0 F) in 1904, marked on the chart; the median year is -21.1 C (-6.0 F).
Coldest night (TNn) at Norwalk by year
Year
Coldest night (TNn)
1893
-23.9 C (-11.0 F)
1894
-21.1 C (-6.0 F)
1895
-20.6 C (-5.1 F)
1896
-23.3 C (-9.9 F)
1897
-20.0 C (-4.0 F)
1898
-25.0 C (-13.0 F)
1899
-26.7 C (-16.1 F)
1900
-19.4 C (-2.9 F)
1901
-21.1 C (-6.0 F)
1902
-21.7 C (-7.1 F)
1903
-24.4 C (-11.9 F)
1904
-30.0 C (-22.0 F)
1905
-23.9 C (-11.0 F)
1906
-19.4 C (-2.9 F)
1907
-26.1 C (-15.0 F)
1908
-21.7 C (-7.1 F)
1909
-20.0 C (-4.0 F)
1910
-21.1 C (-6.0 F)
1911
-19.4 C (-2.9 F)
1912
-21.1 C (-6.0 F)
1913
-16.7 C (1.9 F)
1914
-22.8 C (-9.0 F)
1915
-13.3 C (8.1 F)
1916
-23.9 C (-11.0 F)
1917
-23.9 C (-11.0 F)
1918
-25.6 C (-14.1 F)
1919
-20.6 C (-5.1 F)
1920
-22.2 C (-8.0 F)
1921
-19.4 C (-2.9 F)
1922
-21.1 C (-6.0 F)
1923
-21.7 C (-7.1 F)
1924
-18.9 C (-2.0 F)
1925
-23.3 C (-9.9 F)
1926
-21.1 C (-6.0 F)
1927
-18.9 C (-2.0 F)
1928
-20.0 C (-4.0 F)
1929
-17.8 C (0.0 F)
1930
-23.9 C (-11.0 F)
1931
-16.7 C (1.9 F)
1932
-18.9 C (-2.0 F)
1933
-23.9 C (-11.0 F)
1934
-28.9 C (-20.0 F)
1935
-30.0 C (-22.0 F)
1936
-24.4 C (-11.9 F)
1937
-14.4 C (6.1 F)
1938
-20.0 C (-4.0 F)
1939
-19.4 C (-2.9 F)
1940
-21.7 C (-7.1 F)
1941
-17.2 C (1.0 F)
1942
-26.7 C (-16.1 F)
1943
-28.9 C (-20.0 F)
1944
-21.7 C (-7.1 F)
1945
-20.6 C (-5.1 F)
1946
-20.6 C (-5.1 F)
1947
-20.6 C (-5.1 F)
1948
-27.8 C (-18.0 F)
1949
-18.9 C (-2.0 F)
1950
-25.6 C (-14.1 F)
1951
-18.9 C (-2.0 F)
1952
-20.0 C (-4.0 F)
1953
-13.9 C (7.0 F)
1954
-25.6 C (-14.1 F)
1955
-21.1 C (-6.0 F)
1956
-17.2 C (1.0 F)
Wettest day (Rx1day)
The wettest day of the year at Norwalk, 1893 to 1956. The record is 208.3 mm (8.2 in) in 1955, marked on the chart; the median year is 79.5 mm (3.1 in).
Wettest day (Rx1day) at Norwalk by year
Year
Wettest day (Rx1day)
1893
82.8 mm (3.3 in)
1894
83.8 mm (3.3 in)
1895
56.9 mm (2.2 in)
1896
74.4 mm (2.9 in)
1897
114.3 mm (4.5 in)
1898
104.4 mm (4.1 in)
1899
49.5 mm (1.9 in)
1900
91.9 mm (3.6 in)
1901
109.2 mm (4.3 in)
1902
103.9 mm (4.1 in)
1903
86.9 mm (3.4 in)
1904
96.3 mm (3.8 in)
1905
96.8 mm (3.8 in)
1906
88.9 mm (3.5 in)
1907
80.5 mm (3.2 in)
1908
94.0 mm (3.7 in)
1909
109.5 mm (4.3 in)
1910
69.1 mm (2.7 in)
1911
125.7 mm (4.9 in)
1912
62.7 mm (2.5 in)
1913
101.6 mm (4.0 in)
1914
145.3 mm (5.7 in)
1915
123.2 mm (4.9 in)
1916
59.9 mm (2.4 in)
1917
68.1 mm (2.7 in)
1918
71.6 mm (2.8 in)
1919
80.3 mm (3.2 in)
1920
123.4 mm (4.9 in)
1921
55.4 mm (2.2 in)
1922
72.6 mm (2.9 in)
1923
119.6 mm (4.7 in)
1924
75.2 mm (3.0 in)
1925
86.6 mm (3.4 in)
1926
39.1 mm (1.5 in)
1927
61.2 mm (2.4 in)
1928
44.7 mm (1.8 in)
1929
44.7 mm (1.8 in)
1930
45.5 mm (1.8 in)
1931
71.9 mm (2.8 in)
1932
55.1 mm (2.2 in)
1933
67.6 mm (2.7 in)
1934
69.1 mm (2.7 in)
1935
26.9 mm (1.1 in)
1936
102.1 mm (4.0 in)
1937
97.0 mm (3.8 in)
1938
52.1 mm (2.1 in)
1939
78.7 mm (3.1 in)
1940
71.6 mm (2.8 in)
1941
68.6 mm (2.7 in)
1942
77.7 mm (3.1 in)
1943
78.2 mm (3.1 in)
1944
118.1 mm (4.6 in)
1945
82.6 mm (3.3 in)
1946
105.2 mm (4.1 in)
1947
84.8 mm (3.3 in)
1948
70.1 mm (2.8 in)
1949
59.7 mm (2.4 in)
1950
38.6 mm (1.5 in)
1951
59.4 mm (2.3 in)
1952
87.6 mm (3.4 in)
1953
133.4 mm (5.3 in)
1954
112.3 mm (4.4 in)
1955
208.3 mm (8.2 in)
1956
25.4 mm (1.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Norwalk, 1893 to 1956. The record is 329.7 mm (13.0 in) in 1955, marked on the chart; the median year is 99.3 mm (3.9 in).
Wettest five days (Rx5day) at Norwalk by year
Year
Wettest five days (Rx5day)
1893
118.9 mm (4.7 in)
1894
83.8 mm (3.3 in)
1895
60.5 mm (2.4 in)
1896
86.4 mm (3.4 in)
1897
114.3 mm (4.5 in)
1898
108.7 mm (4.3 in)
1899
85.3 mm (3.4 in)
1900
97.2 mm (3.8 in)
1901
128.8 mm (5.1 in)
1902
132.1 mm (5.2 in)
1903
133.9 mm (5.3 in)
1904
98.4 mm (3.9 in)
1905
137.5 mm (5.4 in)
1906
98.5 mm (3.9 in)
1907
86.4 mm (3.4 in)
1908
179.3 mm (7.1 in)
1909
109.5 mm (4.3 in)
1910
73.4 mm (2.9 in)
1911
148.3 mm (5.8 in)
1912
119.3 mm (4.7 in)
1913
121.9 mm (4.8 in)
1914
147.3 mm (5.8 in)
1915
146.0 mm (5.7 in)
1916
89.2 mm (3.5 in)
1917
80.0 mm (3.1 in)
1918
84.3 mm (3.3 in)
1919
104.3 mm (4.1 in)
1920
142.2 mm (5.6 in)
1921
66.6 mm (2.6 in)
1922
84.3 mm (3.3 in)
1923
138.1 mm (5.4 in)
1924
85.9 mm (3.4 in)
1925
147.3 mm (5.8 in)
1926
46.7 mm (1.8 in)
1927
78.5 mm (3.1 in)
1928
51.6 mm (2.0 in)
1929
73.7 mm (2.9 in)
1930
126.3 mm (5.0 in)
1931
80.5 mm (3.2 in)
1932
65.3 mm (2.6 in)
1933
99.3 mm (3.9 in)
1934
99.3 mm (3.9 in)
1935
51.1 mm (2.0 in)
1936
132.4 mm (5.2 in)
1937
99.0 mm (3.9 in)
1938
88.4 mm (3.5 in)
1939
88.9 mm (3.5 in)
1940
77.4 mm (3.0 in)
1941
87.1 mm (3.4 in)
1942
110.2 mm (4.3 in)
1943
96.3 mm (3.8 in)
1944
214.7 mm (8.5 in)
1945
125.8 mm (5.0 in)
1946
112.3 mm (4.4 in)
1947
131.0 mm (5.2 in)
1948
114.3 mm (4.5 in)
1949
118.4 mm (4.7 in)
1950
70.6 mm (2.8 in)
1951
95.2 mm (3.7 in)
1952
140.5 mm (5.5 in)
1953
180.1 mm (7.1 in)
1954
117.3 mm (4.6 in)
1955
329.7 mm (13.0 in)
1956
63.0 mm (2.5 in)
Longest dry spell (CDD)
The longest dry spell of the year at Norwalk, 1893 to 1956. The record is 44 days in 1924, marked on the chart; the median year is 17 days.
Longest dry spell (CDD) at Norwalk by year
Year
Longest dry spell (CDD)
1893
15 days
1894
19 days
1895
21 days
1896
14 days
1897
12 days
1898
13 days
1899
23 days
1900
19 days
1901
25 days
1902
15 days
1903
36 days
1904
16 days
1905
17 days
1906
16 days
1907
11 days
1908
23 days
1909
25 days
1910
30 days
1911
17 days
1912
17 days
1913
13 days
1914
25 days
1915
22 days
1916
14 days
1917
20 days
1918
19 days
1919
15 days
1920
14 days
1921
16 days
1922
25 days
1923
21 days
1924
44 days
1925
12 days
1926
17 days
1927
13 days
1928
12 days
1929
13 days
1930
21 days
1931
19 days
1932
18 days
1933
12 days
1934
17 days
1935
12 days
1936
13 days
1937
14 days
1938
15 days
1939
26 days
1940
14 days
1941
20 days
1942
20 days
1943
19 days
1944
15 days
1945
11 days
1946
14 days
1947
23 days
1948
20 days
1949
22 days
1950
17 days
1951
12 days
1952
29 days
1953
17 days
1954
11 days
1955
15 days
1956
11 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
60 years with a frost
Across 60 years with a frost, the median last spring frost at Norwalk falls on 1 May and the median first autumn frost on 10 October, which leaves a median of 162 days between them.
In 1925 to 1954 the median growing season was 162 days. The two periods have the same number of growing days.
Fitted over all years, the growing season changes by -1.5 days per decade at this station.
Frost dates and growing season at Norwalk
Measure
Median, all years
Earliest period (1893 to 1924)
Recent period (1925 to 1954)
Recent against earliest
Fitted trend
Last spring frost
1 May
2 May
30 April
2 days earlier
+0.5 days per decade
First autumn frost
10 October
11 October
8 October
3 days earlier
-1.1 days per decade
Growing days
162 days
162 days
162 days
no change
-1.5 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
51 years, 1893 to 1955
A day with at least 84.9 mm (3.3 in) of rain is expected about once in 2 years. A day with at least 176.4 mm (6.9 in) of rain is expected about once in 100 years.
Rainfall return levels at Norwalk: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
84.9 mm (3.3 in)
5 years
110.8 mm (4.4 in)
10 years
127.4 mm (5.0 in)
25 years
147.7 mm (5.8 in)
50 years
162.3 mm (6.4 in)
100 years
176.4 mm (6.9 in)
Longer than the 51 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, 51 years of values from 1893 to 1955.
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: 208.3 mm (8.2 in) in 1955; 145.3 mm (5.7 in) in 1914; 133.4 mm (5.3 in) in 1953.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Norwalk, at 1932 and 1939. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1932 ran 0.3 C (0.5 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1939 ran 0.4 C (0.8 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Norwalk, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1932
+0.3
+0.5
likely
5
1939
-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.
Download the Data
Data for Norwalk standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Norwalk 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.