Record envelope, standing records and threshold days for Chatham (CA008100990), New Brunswick, Canada, with 75 years of record.
Key Facts for Chatham
Chatham (CA008100990) is a weather station in New Brunswick, Canada at 47.05 latitude and -65.48 longitude, 30 m (98 ft) above sea level.
The station reports from 1873 to 1947, 75 years of record.
1,464 records set at Chatham still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Chatham set a daily record low minimum temperature of -12.8 C (9.0 F) on 29 April 1947.
About the Station
Location: New Brunswick, Canada, 47.05 latitude, -65.48 longitude.
Elevation: 30 m (98 ft).
Period of record: 1873 to 1947, 75 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 Chatham. 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 Chatham, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
11.1 C (52.0 F)
-41.7 C (-43.1 F)
n/a
n/a
Feb
12.8 C (55.0 F)
-39.4 C (-38.9 F)
n/a
n/a
Mar
19.4 C (66.9 F)
-32.2 C (-26.0 F)
n/a
n/a
Apr
29.4 C (84.9 F)
-20.0 C (-4.0 F)
n/a
n/a
May
33.9 C (93.0 F)
-6.7 C (19.9 F)
n/a
n/a
Jun
35.6 C (96.1 F)
-1.1 C (30.0 F)
n/a
n/a
Jul
36.7 C (98.1 F)
3.3 C (37.9 F)
n/a
n/a
Aug
38.9 C (102.0 F)
2.2 C (36.0 F)
n/a
n/a
Sep
33.9 C (93.0 F)
-5.0 C (23.0 F)
n/a
n/a
Oct
28.9 C (84.0 F)
-11.1 C (12.0 F)
n/a
n/a
Nov
21.1 C (70.0 F)
-24.4 C (-11.9 F)
n/a
n/a
Dec
14.4 C (57.9 F)
-34.4 C (-29.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Chatham still stand. 1923 holds the most, with 38.
Standing records at Chatham by the year they were set
Year set
Standing records
1873
25
1874
37
1875
20
1876
21
1877
25
1878
21
1879
31
1880
21
1881
24
1882
19
1883
22
1884
31
1885
21
1886
22
1887
16
1888
16
1889
32
1890
13
1891
17
1892
19
1893
12
1894
21
1895
18
1896
12
1897
23
1898
10
1899
13
1900
9
1901
19
1902
19
1903
18
1904
22
1905
14
1906
22
1907
16
1908
20
1909
14
1910
23
1911
17
1912
19
1913
20
1914
26
1915
13
1916
22
1917
13
1918
18
1919
16
1920
26
1921
22
1922
16
1923
38
1924
8
1925
29
1926
15
1927
19
1928
11
1929
12
1930
19
1931
10
1932
13
1933
29
1934
25
1935
17
1936
31
1937
9
1938
26
1939
17
1940
18
1941
19
1942
24
1943
11
1944
20
1945
26
1946
25
1947
7
All-Time Record Progression
5 new records
5 all-time records were set at Chatham between 6 February 1904 and 18 August 1935. Each dot is a new record.
When Chatham set new all-time records
Date
Kind
Detail
1904-02-06
Record low minimum temperature
Record low minimum temperature -39.4 C (-38.9 F)
1905-01-26
Record daily snowfall
Record daily snowfall 83.8 cm (33.0 in)
1906-08-20
Record high maximum temperature
Record high maximum temperature 37.8 C (100.0 F)
1925-01-19
Record low minimum temperature
Record low minimum temperature -41.7 C (-43.1 F)
1935-08-18
Record high maximum temperature
Record high maximum temperature 38.9 C (102.0 F)
Wettest Day of Each Month
Aug: 85.9 mm (3.4 in)
The wettest day on record for each calendar month at Chatham. The most was 85.9 mm (3.4 in) on 19 August 1879.
Record daily precipitation for each month at Chatham
Month
Record daily precipitation (mm)
Date
Jan
83.8 mm (3.3 in)
26 January 1905
Feb
54.4 mm (2.1 in)
12 February 1879
Mar
64.8 mm (2.6 in)
3 March 1882
Apr
48.0 mm (1.9 in)
5 April 1901
May
63.5 mm (2.5 in)
30 May 1912
Jun
54.9 mm (2.2 in)
5 June 1914
Jul
77.7 mm (3.1 in)
9 July 1915
Aug
85.9 mm (3.4 in)
19 August 1879
Sep
84.6 mm (3.3 in)
27 September 1909
Oct
85.9 mm (3.4 in)
24 October 1933
Nov
62.0 mm (2.4 in)
7 November 1907
Dec
73.7 mm (2.9 in)
18 December 1888
Period of Record Coverage
1873 to 1947
Complete yearUnder 90 percent of days
75 years of record at Chatham, 1873 to 1947. 1 years have data for under 90 percent of days and are left out of rankings: 1947.
Cooler than the station meanWarmer than the station mean
One stripe for each of 73 complete years at Chatham, 1873 to 1946. Blue stripes are years cooler than the station's own mean of 4.4 C (39.9 F); red stripes are warmer. The coolest year was 1875, at 2.6 C (36.7 F), and the warmest was 1889, at 6.0 C (42.8 F). The strongest colour marks a difference of 1.9 C (3.4 F).
Annual mean temperature at Chatham as warming stripes, 1873 to 1946
Year
Annual mean temperature
Difference from the station mean
1873
3.5 C
-0.89 C
1874
3.8 C
-0.59 C
1875
2.6 C
-1.80 C
1876
3.9 C
-0.55 C
1877
4.6 C
+0.23 C
1878
5.4 C
+0.97 C
1879
3.3 C
-1.13 C
1880
4.0 C
-0.40 C
1881
4.4 C
+0.01 C
1882
3.6 C
-0.79 C
1883
3.0 C
-1.43 C
1884
3.3 C
-1.15 C
1885
3.6 C
-0.76 C
1886
4.4 C
-0.05 C
1887
3.7 C
-0.70 C
1888
3.5 C
-0.90 C
1889
6.0 C
+1.62 C
1890
3.6 C
-0.83 C
1891
5.2 C
+0.76 C
1892
5.3 C
+0.85 C
1893
3.9 C
-0.46 C
1894
4.3 C
-0.12 C
1895
5.1 C
+0.73 C
1896
4.3 C
-0.13 C
1897
4.7 C
+0.28 C
1898
5.1 C
+0.68 C
1899
4.6 C
+0.17 C
1900
4.7 C
+0.27 C
1901
5.6 C
+1.20 C
1902
5.2 C
+0.79 C
1903
4.3 C
-0.13 C
1904
3.6 C
-0.81 C
1905
4.7 C
+0.28 C
1906
5.6 C
+1.18 C
1907
4.1 C
-0.29 C
1908
5.3 C
+0.87 C
1909
5.1 C
+0.70 C
1910
5.4 C
+0.95 C
1911
5.0 C
+0.60 C
1912
4.4 C
-0.05 C
1913
5.5 C
+1.12 C
1914
4.0 C
-0.40 C
1915
5.7 C
+1.33 C
1916
5.2 C
+0.75 C
1917
3.7 C
-0.66 C
1918
4.2 C
-0.21 C
1919
5.0 C
+0.59 C
1920
4.9 C
+0.46 C
1921
5.3 C
+0.86 C
1923
3.2 C
-1.21 C
1924
3.9 C
-0.55 C
1925
3.6 C
-0.85 C
1926
3.1 C
-1.27 C
1927
4.5 C
+0.14 C
1928
3.9 C
-0.52 C
1929
3.8 C
-0.60 C
1930
4.6 C
+0.23 C
1931
5.5 C
+1.12 C
1932
5.1 C
+0.69 C
1933
4.0 C
-0.42 C
1934
3.4 C
-0.99 C
1935
4.0 C
-0.39 C
1936
4.3 C
-0.07 C
1937
5.4 C
+0.97 C
1938
4.8 C
+0.40 C
1939
4.0 C
-0.45 C
1940
3.9 C
-0.48 C
1941
4.3 C
-0.14 C
1942
5.0 C
+0.57 C
1943
3.7 C
-0.67 C
1944
5.2 C
+0.75 C
1945
4.7 C
+0.32 C
1946
4.9 C
+0.47 C
The fitted trend in annual mean temperature here over 1873 to 1946 is 0.06 C (-0.02 to 0.15) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.12 F (-0.03 to 0.26) per decade. The slope is a straight line fitted to 73 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Chatham
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.06 C (-0.02 to 0.15) per decade
0.12 F (-0.03 to 0.26) per decade
1873 to 1946
73
Not clearly different from zero
Mean daily maximum
0.03 C (-0.05 to 0.11) per decade
0.1 F (-0.1 to 0.2) per decade
1873 to 1946
73
Not clearly different from zero
Mean daily minimum
0.10 C (0.00 to 0.20) per decade
0.18 F (0.00 to 0.35) per decade
1873 to 1946
73
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
1873 to 1947
Yearly extremes at Chatham: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
38.9 C (102.0 F)
1935
33.3 C (91.9 F)
75
Coldest night (TNn)
-41.7 C (-43.1 F)
1925
-32.2 C (-26.0 F)
75
Wettest day (Rx1day)
85.9 mm (3.4 in)
1879
49.0 mm (1.9 in)
75
Wettest five days (Rx5day)
150.9 mm (5.9 in)
1909
75.7 mm (3.0 in)
75
Longest dry spell (CDD)
28 days
1935
13 days
75
Hottest day (TXx)
The hottest day of the year at Chatham, 1873 to 1947. The record is 38.9 C (102.0 F) in 1935, marked on the chart; the median year is 33.3 C (91.9 F).
Hottest day (TXx) at Chatham by year
Year
Hottest day (TXx)
1873
31.7 C (89.1 F)
1874
31.1 C (88.0 F)
1875
31.1 C (88.0 F)
1876
36.7 C (98.1 F)
1877
32.2 C (90.0 F)
1878
36.7 C (98.1 F)
1879
32.8 C (91.0 F)
1880
32.8 C (91.0 F)
1881
33.9 C (93.0 F)
1882
32.8 C (91.0 F)
1883
31.7 C (89.1 F)
1884
33.9 C (93.0 F)
1885
29.4 C (84.9 F)
1886
32.8 C (91.0 F)
1887
33.3 C (91.9 F)
1888
31.1 C (88.0 F)
1889
33.9 C (93.0 F)
1890
33.3 C (91.9 F)
1891
35.0 C (95.0 F)
1892
32.8 C (91.0 F)
1893
36.1 C (97.0 F)
1894
32.8 C (91.0 F)
1895
35.6 C (96.1 F)
1896
33.3 C (91.9 F)
1897
36.1 C (97.0 F)
1898
31.7 C (89.1 F)
1899
31.1 C (88.0 F)
1900
32.8 C (91.0 F)
1901
32.8 C (91.0 F)
1902
31.1 C (88.0 F)
1903
28.9 C (84.0 F)
1904
32.8 C (91.0 F)
1905
33.3 C (91.9 F)
1906
37.8 C (100.0 F)
1907
34.4 C (93.9 F)
1908
35.6 C (96.1 F)
1909
31.7 C (89.1 F)
1910
33.3 C (91.9 F)
1911
35.0 C (95.0 F)
1912
36.7 C (98.1 F)
1913
33.3 C (91.9 F)
1914
32.8 C (91.0 F)
1915
31.1 C (88.0 F)
1916
35.6 C (96.1 F)
1917
35.6 C (96.1 F)
1918
34.4 C (93.9 F)
1919
33.3 C (91.9 F)
1920
34.4 C (93.9 F)
1921
35.0 C (95.0 F)
1922
33.3 C (91.9 F)
1923
35.0 C (95.0 F)
1924
32.8 C (91.0 F)
1925
31.7 C (89.1 F)
1926
33.3 C (91.9 F)
1927
30.6 C (87.1 F)
1928
33.9 C (93.0 F)
1929
32.2 C (90.0 F)
1930
32.8 C (91.0 F)
1931
32.8 C (91.0 F)
1932
32.8 C (91.0 F)
1933
33.9 C (93.0 F)
1934
32.2 C (90.0 F)
1935
38.9 C (102.0 F)
1936
30.0 C (86.0 F)
1937
33.3 C (91.9 F)
1938
33.9 C (93.0 F)
1939
34.4 C (93.9 F)
1940
34.4 C (93.9 F)
1941
33.9 C (93.0 F)
1942
33.9 C (93.0 F)
1943
35.0 C (95.0 F)
1944
37.2 C (99.0 F)
1945
34.4 C (93.9 F)
1946
33.9 C (93.0 F)
1947
13.9 C (57.0 F)
Coldest night (TNn)
The coldest night of the year at Chatham, 1873 to 1947. The record is -41.7 C (-43.1 F) in 1925, marked on the chart; the median year is -32.2 C (-26.0 F).
Coldest night (TNn) at Chatham by year
Year
Coldest night (TNn)
1873
-38.3 C (-36.9 F)
1874
-36.7 C (-34.1 F)
1875
-32.8 C (-27.0 F)
1876
-30.0 C (-22.0 F)
1877
-34.4 C (-29.9 F)
1878
-36.1 C (-33.0 F)
1879
-33.9 C (-29.0 F)
1880
-29.4 C (-20.9 F)
1881
-29.4 C (-20.9 F)
1882
-30.0 C (-22.0 F)
1883
-32.2 C (-26.0 F)
1884
-38.3 C (-36.9 F)
1885
-31.7 C (-25.1 F)
1886
-32.8 C (-27.0 F)
1887
-36.1 C (-33.0 F)
1888
-35.0 C (-31.0 F)
1889
-35.6 C (-32.1 F)
1890
-32.2 C (-26.0 F)
1891
-31.7 C (-25.1 F)
1892
-27.8 C (-18.0 F)
1893
-32.2 C (-26.0 F)
1894
-36.1 C (-33.0 F)
1895
-27.2 C (-17.0 F)
1896
-31.7 C (-25.1 F)
1897
-32.8 C (-27.0 F)
1898
-37.8 C (-36.0 F)
1899
-30.0 C (-22.0 F)
1900
-33.9 C (-29.0 F)
1901
-32.2 C (-26.0 F)
1902
-28.9 C (-20.0 F)
1903
-35.0 C (-31.0 F)
1904
-39.4 C (-38.9 F)
1905
-37.2 C (-35.0 F)
1906
-30.6 C (-23.1 F)
1907
-33.3 C (-27.9 F)
1908
-33.3 C (-27.9 F)
1909
-30.6 C (-23.1 F)
1910
-29.4 C (-20.9 F)
1911
-31.1 C (-24.0 F)
1912
-30.0 C (-22.0 F)
1913
-26.7 C (-16.1 F)
1914
-33.3 C (-27.9 F)
1915
-31.1 C (-24.0 F)
1916
-28.3 C (-18.9 F)
1917
-30.6 C (-23.1 F)
1918
-32.2 C (-26.0 F)
1919
-32.2 C (-26.0 F)
1920
-32.8 C (-27.0 F)
1921
-28.9 C (-20.0 F)
1922
-35.6 C (-32.1 F)
1923
-37.2 C (-35.0 F)
1924
-33.3 C (-27.9 F)
1925
-41.7 C (-43.1 F)
1926
-32.2 C (-26.0 F)
1927
-27.8 C (-18.0 F)
1928
-28.9 C (-20.0 F)
1929
-32.8 C (-27.0 F)
1930
-32.8 C (-27.0 F)
1931
-31.7 C (-25.1 F)
1932
-29.4 C (-20.9 F)
1933
-34.4 C (-29.9 F)
1934
-36.7 C (-34.1 F)
1935
-37.8 C (-36.0 F)
1936
-28.3 C (-18.9 F)
1937
-28.9 C (-20.0 F)
1938
-30.0 C (-22.0 F)
1939
-29.4 C (-20.9 F)
1940
-31.7 C (-25.1 F)
1941
-30.6 C (-23.1 F)
1942
-33.9 C (-29.0 F)
1943
-35.0 C (-31.0 F)
1944
-26.7 C (-16.1 F)
1945
-30.6 C (-23.1 F)
1946
-32.2 C (-26.0 F)
1947
-30.6 C (-23.1 F)
Wettest day (Rx1day)
The wettest day of the year at Chatham, 1873 to 1947. The record is 85.9 mm (3.4 in) in 1879, marked on the chart; the median year is 49.0 mm (1.9 in).
Wettest day (Rx1day) at Chatham by year
Year
Wettest day (Rx1day)
1873
38.9 mm (1.5 in)
1874
50.5 mm (2.0 in)
1875
49.0 mm (1.9 in)
1876
61.7 mm (2.4 in)
1877
69.3 mm (2.7 in)
1878
52.1 mm (2.1 in)
1879
85.9 mm (3.4 in)
1880
34.8 mm (1.4 in)
1881
49.0 mm (1.9 in)
1882
64.8 mm (2.6 in)
1883
43.2 mm (1.7 in)
1884
40.4 mm (1.6 in)
1885
58.4 mm (2.3 in)
1886
33.3 mm (1.3 in)
1887
36.8 mm (1.4 in)
1888
73.7 mm (2.9 in)
1889
43.2 mm (1.7 in)
1890
42.4 mm (1.7 in)
1891
38.6 mm (1.5 in)
1892
66.5 mm (2.6 in)
1893
52.1 mm (2.1 in)
1894
43.4 mm (1.7 in)
1895
35.6 mm (1.4 in)
1896
30.7 mm (1.2 in)
1897
63.5 mm (2.5 in)
1898
42.7 mm (1.7 in)
1899
39.4 mm (1.6 in)
1900
71.6 mm (2.8 in)
1901
48.0 mm (1.9 in)
1902
40.6 mm (1.6 in)
1903
34.5 mm (1.4 in)
1904
39.4 mm (1.6 in)
1905
83.8 mm (3.3 in)
1906
40.4 mm (1.6 in)
1907
62.0 mm (2.4 in)
1908
50.0 mm (2.0 in)
1909
84.6 mm (3.3 in)
1910
38.9 mm (1.5 in)
1911
67.1 mm (2.6 in)
1912
63.5 mm (2.5 in)
1913
38.1 mm (1.5 in)
1914
54.9 mm (2.2 in)
1915
77.7 mm (3.1 in)
1916
58.7 mm (2.3 in)
1917
82.6 mm (3.3 in)
1918
51.8 mm (2.0 in)
1919
35.6 mm (1.4 in)
1920
65.0 mm (2.6 in)
1921
65.5 mm (2.6 in)
1922
47.0 mm (1.9 in)
1923
33.5 mm (1.3 in)
1924
35.3 mm (1.4 in)
1925
46.7 mm (1.8 in)
1926
65.5 mm (2.6 in)
1927
49.5 mm (1.9 in)
1928
37.1 mm (1.5 in)
1929
46.0 mm (1.8 in)
1930
55.9 mm (2.2 in)
1931
47.0 mm (1.9 in)
1932
57.9 mm (2.3 in)
1933
85.9 mm (3.4 in)
1934
47.8 mm (1.9 in)
1935
31.5 mm (1.2 in)
1936
40.4 mm (1.6 in)
1937
62.2 mm (2.4 in)
1938
32.8 mm (1.3 in)
1939
53.8 mm (2.1 in)
1940
64.8 mm (2.6 in)
1941
64.5 mm (2.5 in)
1942
29.7 mm (1.2 in)
1943
49.8 mm (2.0 in)
1944
47.5 mm (1.9 in)
1945
51.1 mm (2.0 in)
1946
24.6 mm (1.0 in)
1947
34.0 mm (1.3 in)
Wettest five days (Rx5day)
The wettest five days of the year at Chatham, 1873 to 1947. The record is 150.9 mm (5.9 in) in 1909, marked on the chart; the median year is 75.7 mm (3.0 in).
Wettest five days (Rx5day) at Chatham by year
Year
Wettest five days (Rx5day)
1873
61.7 mm (2.4 in)
1874
103.3 mm (4.1 in)
1875
75.7 mm (3.0 in)
1876
120.4 mm (4.7 in)
1877
98.5 mm (3.9 in)
1878
75.9 mm (3.0 in)
1879
117.2 mm (4.6 in)
1880
49.5 mm (1.9 in)
1881
106.4 mm (4.2 in)
1882
126.0 mm (5.0 in)
1883
83.6 mm (3.3 in)
1884
65.3 mm (2.6 in)
1885
69.8 mm (2.7 in)
1886
63.0 mm (2.5 in)
1887
58.4 mm (2.3 in)
1888
113.0 mm (4.4 in)
1889
64.0 mm (2.5 in)
1890
75.6 mm (3.0 in)
1891
73.2 mm (2.9 in)
1892
144.0 mm (5.7 in)
1893
117.8 mm (4.6 in)
1894
59.6 mm (2.3 in)
1895
68.7 mm (2.7 in)
1896
60.4 mm (2.4 in)
1897
69.6 mm (2.7 in)
1898
61.9 mm (2.4 in)
1899
80.8 mm (3.2 in)
1900
115.5 mm (4.5 in)
1901
110.6 mm (4.4 in)
1902
89.4 mm (3.5 in)
1903
57.6 mm (2.3 in)
1904
53.6 mm (2.1 in)
1905
92.4 mm (3.6 in)
1906
51.8 mm (2.0 in)
1907
83.6 mm (3.3 in)
1908
69.4 mm (2.7 in)
1909
150.9 mm (5.9 in)
1910
81.3 mm (3.2 in)
1911
126.8 mm (5.0 in)
1912
100.6 mm (4.0 in)
1913
133.9 mm (5.3 in)
1914
69.4 mm (2.7 in)
1915
93.5 mm (3.7 in)
1916
87.9 mm (3.5 in)
1917
101.4 mm (4.0 in)
1918
97.3 mm (3.8 in)
1919
63.8 mm (2.5 in)
1920
97.4 mm (3.8 in)
1921
130.0 mm (5.1 in)
1922
81.3 mm (3.2 in)
1923
71.7 mm (2.8 in)
1924
49.8 mm (2.0 in)
1925
68.8 mm (2.7 in)
1926
92.5 mm (3.6 in)
1927
70.1 mm (2.8 in)
1928
70.1 mm (2.8 in)
1929
51.4 mm (2.0 in)
1930
124.3 mm (4.9 in)
1931
81.4 mm (3.2 in)
1932
62.0 mm (2.4 in)
1933
123.8 mm (4.9 in)
1934
69.9 mm (2.8 in)
1935
61.6 mm (2.4 in)
1936
68.0 mm (2.7 in)
1937
95.5 mm (3.8 in)
1938
47.5 mm (1.9 in)
1939
77.9 mm (3.1 in)
1940
79.0 mm (3.1 in)
1941
75.4 mm (3.0 in)
1942
57.8 mm (2.3 in)
1943
86.1 mm (3.4 in)
1944
71.2 mm (2.8 in)
1945
67.9 mm (2.7 in)
1946
36.6 mm (1.4 in)
1947
55.4 mm (2.2 in)
Longest dry spell (CDD)
The longest dry spell of the year at Chatham, 1873 to 1947. The record is 28 days in 1935, marked on the chart; the median year is 13 days.
Longest dry spell (CDD) at Chatham by year
Year
Longest dry spell (CDD)
1873
20 days
1874
11 days
1875
11 days
1876
12 days
1877
11 days
1878
13 days
1879
24 days
1880
10 days
1881
14 days
1882
16 days
1883
10 days
1884
13 days
1885
15 days
1886
20 days
1887
10 days
1888
11 days
1889
27 days
1890
10 days
1891
15 days
1892
13 days
1893
21 days
1894
15 days
1895
11 days
1896
9 days
1897
11 days
1898
12 days
1899
14 days
1900
15 days
1901
12 days
1902
13 days
1903
15 days
1904
11 days
1905
13 days
1906
10 days
1907
13 days
1908
15 days
1909
10 days
1910
13 days
1911
22 days
1912
11 days
1913
8 days
1914
11 days
1915
10 days
1916
7 days
1917
9 days
1918
10 days
1919
11 days
1920
21 days
1921
20 days
1922
11 days
1923
27 days
1924
20 days
1925
11 days
1926
16 days
1927
14 days
1928
12 days
1929
10 days
1930
18 days
1931
14 days
1932
12 days
1933
13 days
1934
14 days
1935
28 days
1936
8 days
1937
22 days
1938
13 days
1939
11 days
1940
19 days
1941
11 days
1942
11 days
1943
14 days
1944
18 days
1945
10 days
1946
11 days
1947
10 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
73 years with a frost
Across 73 years with a frost, the median last spring frost at Chatham falls on 19 May and the median first autumn frost on 27 September, which leaves a median of 132 days between them.
In 1916 to 1946 the median growing season was 126 days. That is 8 days fewer than in 1873 to 1902.
Fitted over all years, the growing season changes by -1.4 days per decade at this station.
Frost dates and growing season at Chatham
Measure
Median, all years
Earliest period (1873 to 1902)
Recent period (1916 to 1946)
Recent against earliest
Fitted trend
Last spring frost
19 May
18 May
24 May
6 days later
+0.8 days per decade
First autumn frost
27 September
27 September
27 September
no change
-0.5 days per decade
Growing days
132 days
134 days
126 days
8 days fewer
-1.4 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
74 years, 1873 to 1946
A day with at least 49.2 mm (1.9 in) of rain is expected about once in 2 years. A day with at least 97.6 mm (3.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Chatham: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
49.2 mm (1.9 in)
5 years
63.1 mm (2.5 in)
10 years
71.9 mm (2.8 in)
25 years
82.6 mm (3.3 in)
50 years
90.2 mm (3.6 in)
100 years
97.6 mm (3.8 in)
Longer than the 74 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, 74 years of values from 1873 to 1946.
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: 85.9 mm (3.4 in) in 1879; 85.9 mm (3.4 in) in 1933; 84.6 mm (3.3 in) in 1909.
Station Changes
3 suspected
3 changes were suspected in the annual mean temperature of Chatham, at 1899, 1904 and 1923. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1899 ran 0.4 C (0.7 F) lower than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1904 ran 0.6 C (1.2 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1923 ran 0.5 C (1.0 F) lower than in the years before (likely change).
Suspected changes in the annual mean temperature at Chatham, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1899
-0.4
-0.7
likely
5
1904
+0.6
+1.2
likely
5
1923
-0.5
-1.0
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 Chatham standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Chatham 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.