Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Coppermine. 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 Coppermine, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
-2.8 C (27.0 F)
-47.8 C (-54.0 F)
n/a
n/a
Feb
1.1 C (34.0 F)
-50.0 C (-58.0 F)
n/a
n/a
Mar
0.0 C (32.0 F)
-48.9 C (-56.0 F)
n/a
n/a
Apr
7.8 C (46.0 F)
-43.9 C (-47.0 F)
n/a
n/a
May
23.3 C (73.9 F)
-32.2 C (-26.0 F)
n/a
n/a
Jun
27.8 C (82.0 F)
-15.0 C (5.0 F)
n/a
n/a
Jul
32.2 C (90.0 F)
-0.6 C (30.9 F)
n/a
n/a
Aug
29.4 C (84.9 F)
-3.3 C (26.1 F)
n/a
n/a
Sep
26.1 C (79.0 F)
-20.0 C (-4.0 F)
n/a
n/a
Oct
13.9 C (57.0 F)
-33.3 C (-27.9 F)
n/a
n/a
Nov
4.4 C (39.9 F)
-41.1 C (-42.0 F)
n/a
n/a
Dec
4.4 C (39.9 F)
-45.0 C (-49.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Coppermine still stand. 1961 holds the most, with 49.
Standing records at Coppermine by the year they were set
Year set
Standing records
1930
3
1931
36
1932
11
1933
38
1934
42
1935
33
1936
41
1937
33
1938
39
1939
19
1940
42
1941
44
1942
26
1943
42
1944
32
1945
33
1946
31
1947
32
1948
26
1949
29
1950
12
1951
12
1952
37
1953
33
1954
32
1955
39
1956
39
1957
46
1958
31
1959
37
1960
25
1961
49
1962
28
1963
18
1964
29
1965
32
1966
29
1967
25
1968
40
1969
36
1970
30
1971
11
1972
17
1973
31
1974
37
1975
42
1976
18
1977
17
All-Time Record Progression
3 new records
3 all-time records were set at Coppermine between 9 July 1964 and 1 August 1973. Each dot is a new record.
When Coppermine set new all-time records
Date
Kind
Detail
1964-07-09
Record high maximum temperature
Record high maximum temperature 32.2 C (90.0 F)
1968-02-02
Record low maximum temperature
Record low maximum temperature -47.8 C (-54.0 F)
1973-08-01
Record daily precipitation
Record daily precipitation 57.2 mm (2.3 in)
Wettest Day of Each Month
Aug: 57.2 mm (2.3 in)
The wettest day on record for each calendar month at Coppermine. The most was 57.2 mm (2.3 in) on 1 August 1973.
Record daily precipitation for each month at Coppermine
Month
Record daily precipitation (mm)
Date
Jan
10.2 mm (0.4 in)
16 January 1931
Feb
12.7 mm (0.5 in)
23 February 1931
Mar
14.5 mm (0.6 in)
10 March 1945
Apr
21.3 mm (0.8 in)
8 April 1976
May
18.8 mm (0.7 in)
29 May 1976
Jun
25.9 mm (1.0 in)
3 June 1937
Jul
34.3 mm (1.4 in)
30 July 1948
Aug
57.2 mm (2.3 in)
1 August 1973
Sep
22.9 mm (0.9 in)
2 September 1967
Oct
20.6 mm (0.8 in)
11 October 1975
Nov
16.8 mm (0.7 in)
1 November 1975
Dec
14.7 mm (0.6 in)
25 December 1940
Period of Record Coverage
1930 to 1977
Complete yearUnder 90 percent of days
48 years of record at Coppermine, 1930 to 1977. 6 years have data for under 90 percent of days and are left out of rankings: 1930, 1931, 1932, 1941, 1948, 1951.
Cooler than the station meanWarmer than the station mean
One stripe for each of 40 complete years at Coppermine, 1933 to 1976. Blue stripes are years cooler than the station's own mean of -11.5 C (11.4 F); red stripes are warmer. The coolest year was 1936, at -13.9 C (6.9 F), and the warmest was 1943, at -9.4 C (15.1 F). The strongest colour marks a difference of 2.5 C (4.5 F).
Annual mean temperature at Coppermine as warming stripes, 1933 to 1976
Year
Annual mean temperature
Difference from the station mean
1933
-13.2 C
-1.77 C
1934
-12.0 C
-0.55 C
1935
-12.0 C
-0.56 C
1936
-13.9 C
-2.47 C
1937
-10.9 C
+0.52 C
1938
-9.7 C
+1.79 C
1939
-11.2 C
+0.24 C
1940
-9.5 C
+1.95 C
1942
-10.8 C
+0.68 C
1943
-9.4 C
+2.10 C
1944
-9.4 C
+2.09 C
1945
-11.5 C
-0.01 C
1946
-11.8 C
-0.30 C
1947
-12.0 C
-0.57 C
1950
-11.8 C
-0.31 C
1952
-10.9 C
+0.61 C
1953
-9.8 C
+1.67 C
1954
-11.1 C
+0.37 C
1955
-12.1 C
-0.60 C
1956
-12.4 C
-0.95 C
1957
-12.1 C
-0.63 C
1958
-11.5 C
-0.08 C
1959
-12.3 C
-0.88 C
1960
-11.6 C
-0.14 C
1961
-13.3 C
-1.84 C
1962
-11.3 C
+0.17 C
1963
-10.8 C
+0.70 C
1964
-12.4 C
-0.90 C
1965
-12.8 C
-1.34 C
1966
-11.5 C
-0.01 C
1967
-11.7 C
-0.21 C
1968
-11.1 C
+0.41 C
1969
-10.1 C
+1.36 C
1970
-11.7 C
-0.27 C
1971
-10.9 C
+0.58 C
1972
-13.0 C
-1.56 C
1973
-9.9 C
+1.58 C
1974
-13.4 C
-1.98 C
1975
-10.9 C
+0.59 C
1976
-10.8 C
+0.69 C
The fitted trend in annual mean temperature here over 1933 to 1976 is -0.05 C (-0.33 to 0.24) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.6 to 0.4) per decade. The slope is a straight line fitted to 40 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Coppermine
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.05 C (-0.33 to 0.24) per decade
-0.1 F (-0.6 to 0.4) per decade
1933 to 1976
40
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.4 to 0.2) per decade
-0.1 F (-0.7 to 0.4) per decade
1933 to 1976
40
Not clearly different from zero
Mean daily minimum
-0.04 C (-0.31 to 0.24) per decade
-0.1 F (-0.6 to 0.4) per decade
1933 to 1976
40
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
1930 to 1977
Yearly extremes at Coppermine: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
32.2 C (90.0 F)
1964
26.1 C (79.0 F)
48
Coldest night (TNn)
-50.0 C (-58.0 F)
1947
-45.0 C (-49.0 F)
48
Wettest day (Rx1day)
57.2 mm (2.3 in)
1973
18.0 mm (0.7 in)
48
Wettest five days (Rx5day)
69.1 mm (2.7 in)
1937
26.9 mm (1.1 in)
48
Longest dry spell (CDD)
86 days
1955
37 days
48
Hottest day (TXx)
The hottest day of the year at Coppermine, 1930 to 1977. The record is 32.2 C (90.0 F) in 1964, marked on the chart; the median year is 26.1 C (79.0 F).
Hottest day (TXx) at Coppermine by year
Year
Hottest day (TXx)
1930
4.4 C (39.9 F)
1931
28.9 C (84.0 F)
1932
23.3 C (73.9 F)
1933
27.2 C (81.0 F)
1934
25.6 C (78.1 F)
1935
27.2 C (81.0 F)
1936
30.6 C (87.1 F)
1937
22.2 C (72.0 F)
1938
23.3 C (73.9 F)
1939
23.3 C (73.9 F)
1940
26.1 C (79.0 F)
1941
26.7 C (80.1 F)
1942
24.4 C (75.9 F)
1943
27.8 C (82.0 F)
1944
25.0 C (77.0 F)
1945
28.3 C (82.9 F)
1946
27.2 C (81.0 F)
1947
27.8 C (82.0 F)
1948
29.4 C (84.9 F)
1949
22.8 C (73.0 F)
1950
25.6 C (78.1 F)
1951
22.8 C (73.0 F)
1952
23.3 C (73.9 F)
1953
26.1 C (79.0 F)
1954
28.3 C (82.9 F)
1955
27.2 C (81.0 F)
1956
25.0 C (77.0 F)
1957
26.1 C (79.0 F)
1958
24.4 C (75.9 F)
1959
22.2 C (72.0 F)
1960
27.8 C (82.0 F)
1961
28.9 C (84.0 F)
1962
24.4 C (75.9 F)
1963
27.2 C (81.0 F)
1964
32.2 C (90.0 F)
1965
24.4 C (75.9 F)
1966
28.3 C (82.9 F)
1967
26.1 C (79.0 F)
1968
23.9 C (75.0 F)
1969
27.8 C (82.0 F)
1970
26.1 C (79.0 F)
1971
28.9 C (84.0 F)
1972
22.8 C (73.0 F)
1973
29.4 C (84.9 F)
1974
26.7 C (80.1 F)
1975
25.6 C (78.1 F)
1976
25.6 C (78.1 F)
1977
27.5 C (81.5 F)
Coldest night (TNn)
The coldest night of the year at Coppermine, 1930 to 1977. The record is -50.0 C (-58.0 F) in 1947, marked on the chart; the median year is -45.0 C (-49.0 F).
Coldest night (TNn) at Coppermine by year
Year
Coldest night (TNn)
1930
-41.1 C (-42.0 F)
1931
-46.7 C (-52.1 F)
1932
-37.8 C (-36.0 F)
1933
-41.7 C (-43.1 F)
1934
-45.6 C (-50.1 F)
1935
-46.1 C (-51.0 F)
1936
-47.8 C (-54.0 F)
1937
-45.0 C (-49.0 F)
1938
-43.3 C (-45.9 F)
1939
-45.0 C (-49.0 F)
1940
-40.0 C (-40.0 F)
1941
-48.3 C (-54.9 F)
1942
-47.2 C (-53.0 F)
1943
-45.6 C (-50.1 F)
1944
-41.7 C (-43.1 F)
1945
-41.7 C (-43.1 F)
1946
-45.0 C (-49.0 F)
1947
-50.0 C (-58.0 F)
1948
-41.7 C (-43.1 F)
1949
-45.0 C (-49.0 F)
1950
-42.8 C (-45.0 F)
1951
-45.0 C (-49.0 F)
1952
-46.1 C (-51.0 F)
1953
-45.0 C (-49.0 F)
1954
-45.6 C (-50.1 F)
1955
-48.9 C (-56.0 F)
1956
-45.0 C (-49.0 F)
1957
-43.9 C (-47.0 F)
1958
-45.0 C (-49.0 F)
1959
-43.3 C (-45.9 F)
1960
-46.7 C (-52.1 F)
1961
-45.6 C (-50.1 F)
1962
-44.4 C (-47.9 F)
1963
-43.3 C (-45.9 F)
1964
-44.4 C (-47.9 F)
1965
-48.9 C (-56.0 F)
1966
-47.2 C (-53.0 F)
1967
-44.4 C (-47.9 F)
1968
-50.0 C (-58.0 F)
1969
-44.4 C (-47.9 F)
1970
-43.9 C (-47.0 F)
1971
-46.1 C (-51.0 F)
1972
-45.6 C (-50.1 F)
1973
-42.8 C (-45.0 F)
1974
-44.4 C (-47.9 F)
1975
-47.8 C (-54.0 F)
1976
-45.0 C (-49.0 F)
1977
-43.6 C (-46.5 F)
Wettest day (Rx1day)
The wettest day of the year at Coppermine, 1930 to 1977. The record is 57.2 mm (2.3 in) in 1973, marked on the chart; the median year is 18.0 mm (0.7 in).
Wettest day (Rx1day) at Coppermine by year
Year
Wettest day (Rx1day)
1930
20.3 mm (0.8 in)
1931
15.2 mm (0.6 in)
1932
13.7 mm (0.5 in)
1933
9.4 mm (0.37 in)
1934
19.1 mm (0.8 in)
1935
18.5 mm (0.7 in)
1936
21.1 mm (0.8 in)
1937
48.0 mm (1.9 in)
1938
16.8 mm (0.7 in)
1939
18.5 mm (0.7 in)
1940
14.7 mm (0.6 in)
1941
16.8 mm (0.7 in)
1942
20.3 mm (0.8 in)
1943
30.7 mm (1.2 in)
1944
14.0 mm (0.6 in)
1945
14.5 mm (0.6 in)
1946
23.9 mm (0.9 in)
1947
18.0 mm (0.7 in)
1948
34.8 mm (1.4 in)
1949
17.8 mm (0.7 in)
1950
18.3 mm (0.7 in)
1951
13.7 mm (0.5 in)
1952
8.4 mm (0.33 in)
1953
36.1 mm (1.4 in)
1954
10.4 mm (0.4 in)
1955
18.0 mm (0.7 in)
1956
17.5 mm (0.7 in)
1957
18.3 mm (0.7 in)
1958
9.4 mm (0.37 in)
1959
12.7 mm (0.5 in)
1960
30.7 mm (1.2 in)
1961
15.5 mm (0.6 in)
1962
8.1 mm (0.32 in)
1963
20.3 mm (0.8 in)
1964
12.7 mm (0.5 in)
1965
30.0 mm (1.2 in)
1966
36.1 mm (1.4 in)
1967
22.9 mm (0.9 in)
1968
8.1 mm (0.32 in)
1969
16.0 mm (0.6 in)
1970
14.7 mm (0.6 in)
1971
18.5 mm (0.7 in)
1972
11.9 mm (0.5 in)
1973
57.2 mm (2.3 in)
1974
20.1 mm (0.8 in)
1975
20.6 mm (0.8 in)
1976
21.3 mm (0.8 in)
1977
12.0 mm (0.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Coppermine, 1930 to 1977. The record is 69.1 mm (2.7 in) in 1937, marked on the chart; the median year is 26.9 mm (1.1 in).
Wettest five days (Rx5day) at Coppermine by year
Year
Wettest five days (Rx5day)
1930
30.5 mm (1.2 in)
1931
19.3 mm (0.8 in)
1932
29.1 mm (1.1 in)
1933
11.2 mm (0.4 in)
1934
29.0 mm (1.1 in)
1935
25.4 mm (1.0 in)
1936
29.5 mm (1.2 in)
1937
69.1 mm (2.7 in)
1938
30.5 mm (1.2 in)
1939
46.8 mm (1.8 in)
1940
23.1 mm (0.9 in)
1941
27.5 mm (1.1 in)
1942
20.6 mm (0.8 in)
1943
36.6 mm (1.4 in)
1944
24.4 mm (1.0 in)
1945
31.7 mm (1.2 in)
1946
26.4 mm (1.0 in)
1947
38.0 mm (1.5 in)
1948
54.6 mm (2.1 in)
1949
19.4 mm (0.8 in)
1950
23.9 mm (0.9 in)
1951
19.5 mm (0.8 in)
1952
15.6 mm (0.6 in)
1953
65.3 mm (2.6 in)
1954
13.8 mm (0.5 in)
1955
32.8 mm (1.3 in)
1956
45.2 mm (1.8 in)
1957
22.1 mm (0.9 in)
1958
16.3 mm (0.6 in)
1959
21.6 mm (0.9 in)
1960
59.0 mm (2.3 in)
1961
24.6 mm (1.0 in)
1962
15.3 mm (0.6 in)
1963
33.3 mm (1.3 in)
1964
18.3 mm (0.7 in)
1965
42.5 mm (1.7 in)
1966
54.9 mm (2.2 in)
1967
27.7 mm (1.1 in)
1968
14.7 mm (0.6 in)
1969
27.4 mm (1.1 in)
1970
22.9 mm (0.9 in)
1971
25.1 mm (1.0 in)
1972
22.6 mm (0.9 in)
1973
63.0 mm (2.5 in)
1974
21.1 mm (0.8 in)
1975
29.7 mm (1.2 in)
1976
46.5 mm (1.8 in)
1977
15.9 mm (0.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Coppermine, 1930 to 1977. The record is 86 days in 1955, marked on the chart; the median year is 37 days.
Longest dry spell (CDD) at Coppermine by year
Year
Longest dry spell (CDD)
1930
11 days
1931
25 days
1932
22 days
1933
45 days
1934
51 days
1935
25 days
1936
34 days
1937
50 days
1938
32 days
1939
51 days
1940
27 days
1941
20 days
1942
24 days
1943
29 days
1944
46 days
1945
72 days
1946
36 days
1947
24 days
1948
46 days
1949
28 days
1950
38 days
1951
44 days
1952
35 days
1953
78 days
1954
61 days
1955
86 days
1956
78 days
1957
37 days
1958
43 days
1959
32 days
1960
29 days
1961
45 days
1962
35 days
1963
78 days
1964
31 days
1965
28 days
1966
63 days
1967
53 days
1968
37 days
1969
36 days
1970
61 days
1971
25 days
1972
39 days
1973
38 days
1974
40 days
1975
21 days
1976
17 days
1977
21 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
40 years with a frost
Across 40 years with a frost, the median last spring frost at Coppermine falls on 24 June and the median first autumn frost on 20 August, which leaves a median of 59 days between them.
Fitted over all years, the growing season changes by +2.6 days per decade at this station.
Frost dates and growing season at Coppermine
Measure
Median, all years
Earliest period
Recent period (1944 to 1976)
Recent against earliest
Fitted trend
Last spring frost
24 June
n/a
23 June
n/a
-0.8 days per decade
First autumn frost
20 August
n/a
20 August
n/a
+1.8 days per decade
Growing days
59 days
n/a
60 days
n/a
+2.6 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
45 years, 1933 to 1977
A day with at least 17.3 mm (0.7 in) of rain is expected about once in 2 years. A day with at least 59.4 mm (2.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Coppermine: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
17.3 mm (0.7 in)
5 years
25.4 mm (1.0 in)
10 years
31.8 mm (1.3 in)
25 years
41.4 mm (1.6 in)
50 years
49.8 mm (2.0 in)
Longer than the 45 years of record
100 years
59.4 mm (2.3 in)
Longer than the 45 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, 45 years of values from 1933 to 1977.
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: 57.2 mm (2.3 in) in 1973; 48.0 mm (1.9 in) in 1937; 36.1 mm (1.4 in) in 1953.
Download the Data
Data for Coppermine standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Coppermine 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.