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
16.7 C (62.1 F)
-23.3 C (-9.9 F)
n/a
n/a
Feb
17.8 C (64.0 F)
-28.3 C (-18.9 F)
n/a
n/a
Mar
25.6 C (78.1 F)
-20.6 C (-5.1 F)
n/a
n/a
Apr
29.4 C (84.9 F)
-11.1 C (12.0 F)
n/a
n/a
May
33.3 C (91.9 F)
-2.8 C (27.0 F)
n/a
n/a
Jun
37.2 C (99.0 F)
2.2 C (36.0 F)
n/a
n/a
Jul
40.0 C (104.0 F)
6.7 C (44.1 F)
n/a
n/a
Aug
36.7 C (98.1 F)
3.9 C (39.0 F)
n/a
n/a
Sep
36.1 C (97.0 F)
-1.1 C (30.0 F)
n/a
n/a
Oct
30.6 C (87.1 F)
-6.1 C (21.0 F)
n/a
n/a
Nov
25.6 C (78.1 F)
-15.0 C (5.0 F)
n/a
n/a
Dec
16.7 C (62.1 F)
-23.3 C (-9.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Chatham still stand. 1934 holds the most, with 79.
Standing records at Chatham by the year they were set
Year set
Standing records
1933
19
1934
79
1935
40
1936
72
1937
39
1938
41
1939
41
1940
49
1941
41
1942
57
1943
48
1944
44
1945
69
1946
44
1947
43
1948
44
1949
50
1950
49
1951
43
1952
38
1953
35
1954
38
1955
35
1956
36
1957
25
1958
35
1959
28
1960
33
1961
20
1962
39
1963
40
1964
48
1965
45
1966
27
1967
30
Wettest Day of Each Month
Aug: 107.4 mm (4.2 in)
The wettest day on record for each calendar month at Chatham. The most was 107.4 mm (4.2 in) on 17 August 1946.
Record daily precipitation for each month at Chatham
Month
Record daily precipitation (mm)
Date
Jan
38.6 mm (1.5 in)
12 January 1960
Feb
64.3 mm (2.5 in)
12 February 1938
Mar
42.4 mm (1.7 in)
25 March 1954
Apr
42.7 mm (1.7 in)
5 April 1947
May
63.0 mm (2.5 in)
10 May 1948
Jun
72.4 mm (2.9 in)
17 June 1946
Jul
83.8 mm (3.3 in)
4 July 1943
Aug
107.4 mm (4.2 in)
17 August 1946
Sep
40.9 mm (1.6 in)
23 September 1955
Oct
72.9 mm (2.9 in)
3 October 1954
Nov
46.0 mm (1.8 in)
9 November 1962
Dec
42.2 mm (1.7 in)
24 December 1965
Period of Record Coverage
1933 to 1967
Complete yearUnder 90 percent of days
35 years of record at Chatham, 1933 to 1967. 1 years have data for under 90 percent of days and are left out of rankings: 1933.
Cooler than the station meanWarmer than the station mean
One stripe for each of 32 complete years at Chatham, 1934 to 1966. Blue stripes are years cooler than the station's own mean of 9.2 C (48.6 F); red stripes are warmer. The coolest year was 1940, at 8.3 C (46.9 F), and the warmest was 1949, at 10.6 C (51.0 F). The strongest colour marks a difference of 1.4 C (2.5 F).
Annual mean temperature at Chatham as warming stripes, 1934 to 1966
Year
Annual mean temperature
Difference from the station mean
1934
8.6 C
-0.59 C
1935
8.3 C
-0.88 C
1936
8.5 C
-0.75 C
1937
8.8 C
-0.45 C
1938
9.9 C
+0.65 C
1939
9.5 C
+0.33 C
1940
8.3 C
-0.94 C
1941
10.1 C
+0.92 C
1942
9.2 C
-0.06 C
1943
8.5 C
-0.72 C
1944
9.4 C
+0.23 C
1945
8.6 C
-0.65 C
1946
10.0 C
+0.78 C
1947
9.0 C
-0.17 C
1948
9.2 C
-0.06 C
1949
10.6 C
+1.35 C
1950
8.6 C
-0.65 C
1951
9.0 C
-0.25 C
1952
9.9 C
+0.73 C
1953
10.5 C
+1.27 C
1954
9.8 C
+0.58 C
1955
10.4 C
+1.15 C
1956
9.3 C
+0.12 C
1957
9.3 C
+0.04 C
1958
8.7 C
-0.53 C
1959
9.5 C
+0.32 C
1960
9.0 C
-0.23 C
1961
9.4 C
+0.23 C
1963
8.4 C
-0.83 C
1964
9.2 C
+0.02 C
1965
8.6 C
-0.58 C
1966
8.8 C
-0.39 C
The fitted trend in annual mean temperature here over 1934 to 1966 is 0.1 C (-0.2 to 0.3) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.3 to 0.6) per decade. The slope is a straight line fitted to 32 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
0.1 C (-0.2 to 0.3) per decade
0.1 F (-0.3 to 0.6) per decade
1934 to 1966
32
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.3 to 0.2) per decade
-0.1 F (-0.6 to 0.3) per decade
1934 to 1966
32
Not clearly different from zero
Mean daily minimum
0.2 C (-0.1 to 0.5) per decade
0.4 F (-0.1 to 0.9) per decade
1934 to 1966
32
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
1933 to 1967
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)
40.0 C (104.0 F)
1936
35.0 C (95.0 F)
35
Coldest night (TNn)
-28.3 C (-18.9 F)
1934
-20.6 C (-5.1 F)
35
Wettest day (Rx1day)
107.4 mm (4.2 in)
1946
43.9 mm (1.7 in)
35
Wettest five days (Rx5day)
110.4 mm (4.3 in)
1946
68.7 mm (2.7 in)
35
Longest dry spell (CDD)
32 days
1963
16 days
35
Hottest day (TXx)
The hottest day of the year at Chatham, 1933 to 1967. The record is 40.0 C (104.0 F) in 1936, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Chatham by year
Year
Hottest day (TXx)
1933
25.0 C (77.0 F)
1934
38.9 C (102.0 F)
1935
36.1 C (97.0 F)
1936
40.0 C (104.0 F)
1937
33.9 C (93.0 F)
1938
33.3 C (91.9 F)
1939
35.6 C (96.1 F)
1940
35.6 C (96.1 F)
1941
36.1 C (97.0 F)
1942
35.0 C (95.0 F)
1943
35.0 C (95.0 F)
1944
37.2 C (99.0 F)
1945
33.3 C (91.9 F)
1946
35.6 C (96.1 F)
1947
35.0 C (95.0 F)
1948
36.7 C (98.1 F)
1949
35.6 C (96.1 F)
1950
33.9 C (93.0 F)
1951
31.1 C (88.0 F)
1952
36.7 C (98.1 F)
1953
36.1 C (97.0 F)
1954
35.6 C (96.1 F)
1955
36.7 C (98.1 F)
1956
34.4 C (93.9 F)
1957
33.3 C (91.9 F)
1958
32.2 C (90.0 F)
1959
33.3 C (91.9 F)
1960
32.8 C (91.0 F)
1961
32.8 C (91.0 F)
1962
33.3 C (91.9 F)
1963
33.3 C (91.9 F)
1964
35.0 C (95.0 F)
1965
33.3 C (91.9 F)
1966
35.6 C (96.1 F)
1967
34.4 C (93.9 F)
Coldest night (TNn)
The coldest night of the year at Chatham, 1933 to 1967. The record is -28.3 C (-18.9 F) in 1934, marked on the chart; the median year is -20.6 C (-5.1 F).
Coldest night (TNn) at Chatham by year
Year
Coldest night (TNn)
1933
-19.4 C (-2.9 F)
1934
-28.3 C (-18.9 F)
1935
-21.7 C (-7.1 F)
1936
-21.7 C (-7.1 F)
1937
-16.7 C (1.9 F)
1938
-17.8 C (0.0 F)
1939
-20.6 C (-5.1 F)
1940
-22.2 C (-8.0 F)
1941
-15.0 C (5.0 F)
1942
-21.1 C (-6.0 F)
1943
-21.7 C (-7.1 F)
1944
-23.3 C (-9.9 F)
1945
-22.2 C (-8.0 F)
1946
-18.9 C (-2.0 F)
1947
-17.2 C (1.0 F)
1948
-23.3 C (-9.9 F)
1949
-13.9 C (7.0 F)
1950
-23.3 C (-9.9 F)
1951
-21.7 C (-7.1 F)
1952
-13.3 C (8.1 F)
1953
-16.7 C (1.9 F)
1954
-17.8 C (0.0 F)
1955
-17.2 C (1.0 F)
1956
-15.6 C (3.9 F)
1957
-19.4 C (-2.9 F)
1958
-21.7 C (-7.1 F)
1959
-19.4 C (-2.9 F)
1960
-20.0 C (-4.0 F)
1961
-23.3 C (-9.9 F)
1962
-23.9 C (-11.0 F)
1963
-23.3 C (-9.9 F)
1964
-16.7 C (1.9 F)
1965
-20.6 C (-5.1 F)
1966
-20.6 C (-5.1 F)
1967
-18.9 C (-2.0 F)
Wettest day (Rx1day)
The wettest day of the year at Chatham, 1933 to 1967. The record is 107.4 mm (4.2 in) in 1946, marked on the chart; the median year is 43.9 mm (1.7 in).
Wettest day (Rx1day) at Chatham by year
Year
Wettest day (Rx1day)
1933
11.2 mm (0.4 in)
1934
30.0 mm (1.2 in)
1935
22.6 mm (0.9 in)
1936
30.0 mm (1.2 in)
1937
34.8 mm (1.4 in)
1938
64.3 mm (2.5 in)
1939
49.0 mm (1.9 in)
1940
49.8 mm (2.0 in)
1941
57.2 mm (2.3 in)
1942
32.3 mm (1.3 in)
1943
83.8 mm (3.3 in)
1944
29.2 mm (1.1 in)
1945
50.3 mm (2.0 in)
1946
107.4 mm (4.2 in)
1947
51.8 mm (2.0 in)
1948
63.0 mm (2.5 in)
1949
32.8 mm (1.3 in)
1950
43.4 mm (1.7 in)
1951
39.1 mm (1.5 in)
1952
48.3 mm (1.9 in)
1953
38.9 mm (1.5 in)
1954
72.9 mm (2.9 in)
1955
40.9 mm (1.6 in)
1956
70.4 mm (2.8 in)
1957
42.2 mm (1.7 in)
1958
50.5 mm (2.0 in)
1959
43.9 mm (1.7 in)
1960
38.6 mm (1.5 in)
1961
53.8 mm (2.1 in)
1962
46.0 mm (1.8 in)
1963
27.9 mm (1.1 in)
1964
51.1 mm (2.0 in)
1965
42.2 mm (1.7 in)
1966
35.8 mm (1.4 in)
1967
58.2 mm (2.3 in)
Wettest five days (Rx5day)
The wettest five days of the year at Chatham, 1933 to 1967. The record is 110.4 mm (4.3 in) in 1946, marked on the chart; the median year is 68.7 mm (2.7 in).
Wettest five days (Rx5day) at Chatham by year
Year
Wettest five days (Rx5day)
1933
20.3 mm (0.8 in)
1934
33.5 mm (1.3 in)
1935
30.9 mm (1.2 in)
1936
43.4 mm (1.7 in)
1937
60.8 mm (2.4 in)
1938
78.8 mm (3.1 in)
1939
73.5 mm (2.9 in)
1940
80.0 mm (3.1 in)
1941
64.8 mm (2.6 in)
1942
47.4 mm (1.9 in)
1943
98.0 mm (3.9 in)
1944
42.5 mm (1.7 in)
1945
109.7 mm (4.3 in)
1946
110.4 mm (4.3 in)
1947
100.8 mm (4.0 in)
1948
107.4 mm (4.2 in)
1949
57.4 mm (2.3 in)
1950
62.4 mm (2.5 in)
1951
56.9 mm (2.2 in)
1952
68.7 mm (2.7 in)
1953
52.9 mm (2.1 in)
1954
109.7 mm (4.3 in)
1955
57.1 mm (2.2 in)
1956
89.6 mm (3.5 in)
1957
74.9 mm (2.9 in)
1958
57.7 mm (2.3 in)
1959
97.0 mm (3.8 in)
1960
87.9 mm (3.5 in)
1961
75.1 mm (3.0 in)
1962
58.5 mm (2.3 in)
1963
50.3 mm (2.0 in)
1964
71.4 mm (2.8 in)
1965
53.9 mm (2.1 in)
1966
81.3 mm (3.2 in)
1967
96.1 mm (3.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Chatham, 1933 to 1967. The record is 32 days in 1963, marked on the chart; the median year is 16 days.
Longest dry spell (CDD) at Chatham by year
Year
Longest dry spell (CDD)
1933
8 days
1934
20 days
1935
14 days
1936
23 days
1937
14 days
1938
15 days
1939
15 days
1940
12 days
1941
24 days
1942
20 days
1943
18 days
1944
24 days
1945
13 days
1946
13 days
1947
16 days
1948
14 days
1949
20 days
1950
13 days
1951
16 days
1952
26 days
1953
19 days
1954
27 days
1955
15 days
1956
13 days
1957
23 days
1958
30 days
1959
12 days
1960
14 days
1961
18 days
1962
21 days
1963
32 days
1964
20 days
1965
11 days
1966
15 days
1967
19 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
32 years with a frost
Across 32 years with a frost, the median last spring frost at Chatham falls on 30 April and the median first autumn frost on 19 October, which leaves a median of 171 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 Chatham
Measure
Median, all years
Earliest period
Recent period (1936 to 1966)
Recent against earliest
Fitted trend
Last spring frost
30 April
n/a
29 April
n/a
-0.5 days per decade
First autumn frost
19 October
n/a
21 October
n/a
+1.9 days per decade
Growing days
171 days
n/a
172 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
34 years, 1934 to 1967
A day with at least 44.4 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 108.6 mm (4.3 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
44.4 mm (1.7 in)
5 years
59.5 mm (2.3 in)
10 years
70.2 mm (2.8 in)
25 years
84.9 mm (3.3 in)
50 years
96.5 mm (3.8 in)
Longer than the 34 years of record
100 years
108.6 mm (4.3 in)
Longer than the 34 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, 34 years of values from 1934 to 1967.
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: 107.4 mm (4.2 in) in 1946; 83.8 mm (3.3 in) in 1943; 72.9 mm (2.9 in) in 1954.
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.