Record envelope, standing records and threshold days for Copperhill (USC00402024), Tennessee, United States, with 96 years of record.
Key Facts for Copperhill
Copperhill (USC00402024) is a weather station in Tennessee, United States at 34.99 latitude and -84.38 longitude, 442 m (1,450 ft) above sea level.
The station reports from 1914 to 2009, 96 years of record.
1,464 records set at Copperhill still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Copperhill set a daily record low maximum temperature of -7.8 C (18.0 F) on 16 January 2009.
About the Station
Location: Tennessee, United States, 34.99 latitude, -84.38 longitude.
Elevation: 442 m (1,450 ft).
Period of record: 1914 to 2009, 96 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 Copperhill. 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 Copperhill, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.6 C (78.1 F)
-26.7 C (-16.1 F)
n/a
n/a
Feb
26.7 C (80.1 F)
-20.6 C (-5.1 F)
n/a
n/a
Mar
31.1 C (88.0 F)
-15.0 C (5.0 F)
n/a
n/a
Apr
34.4 C (93.9 F)
-8.3 C (17.1 F)
n/a
n/a
May
35.6 C (96.1 F)
-1.7 C (28.9 F)
n/a
n/a
Jun
38.3 C (100.9 F)
2.8 C (37.0 F)
n/a
n/a
Jul
39.4 C (102.9 F)
8.3 C (46.9 F)
n/a
n/a
Aug
38.3 C (100.9 F)
6.7 C (44.1 F)
n/a
n/a
Sep
39.4 C (102.9 F)
-1.1 C (30.0 F)
n/a
n/a
Oct
35.0 C (95.0 F)
-7.2 C (19.0 F)
n/a
n/a
Nov
28.3 C (82.9 F)
-18.3 C (-0.9 F)
n/a
n/a
Dec
24.4 C (75.9 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 Copperhill still stand. 1915 holds the most, with 53.
Standing records at Copperhill by the year they were set
Year set
Standing records
1914
52
1915
53
1916
45
1917
24
1918
24
1919
41
1920
7
1921
11
1922
12
1923
7
1924
14
1925
37
1926
14
1927
31
1928
22
1929
23
1930
24
1931
24
1932
17
1933
18
1934
8
1935
15
1936
21
1937
20
1938
11
1939
8
1940
26
1941
14
1942
7
1943
23
1944
8
1945
13
1946
10
1947
8
1948
14
1949
14
1950
17
1951
12
1952
21
1953
14
1954
19
1955
13
1956
18
1957
13
1958
15
1959
7
1960
18
1961
19
1962
15
1963
21
1964
14
1965
9
1966
11
1967
32
1968
14
1969
3
1970
16
1971
7
1972
17
1973
13
1974
21
1975
8
1976
19
1977
13
1978
5
1979
14
1980
12
1981
6
1982
13
1983
17
1984
23
1985
16
1986
16
1987
3
1988
5
1989
18
1990
5
1991
12
1992
9
1993
11
1994
4
1995
12
1996
20
1997
10
1998
11
1999
8
2000
15
2001
8
2002
11
2003
4
2004
9
2005
6
2006
3
2007
10
2008
8
2009
1
All-Time Record Progression
6 new records
6 all-time records were set at Copperhill between 13 December 1962 and 14 July 1990. Each dot is a new record.
When Copperhill set new all-time records
Date
Kind
Detail
1962-12-13
Record low maximum temperature
Record low maximum temperature -12.2 C (10.0 F)
1982-01-11
Record low maximum temperature
Record low maximum temperature -13.3 C (8.1 F)
1983-12-24
Record low minimum temperature
Record low minimum temperature -27.2 C (-17.0 F)
1985-01-20
Record low maximum temperature
Record low maximum temperature -16.1 C (3.0 F)
1990-02-16
Record daily precipitation
Record daily precipitation 137.2 mm (5.4 in)
1990-07-14
Record daily precipitation
Record daily precipitation 137.7 mm (5.4 in)
Wettest Day of Each Month
Jul: 137.7 mm (5.4 in)
The wettest day on record for each calendar month at Copperhill. The most was 137.7 mm (5.4 in) on 14 July 1990.
Record daily precipitation for each month at Copperhill
Month
Record daily precipitation (mm)
Date
Jan
102.6 mm (4.0 in)
27 January 1996
Feb
137.2 mm (5.4 in)
16 February 1990
Mar
133.1 mm (5.2 in)
29 March 1951
Apr
135.1 mm (5.3 in)
2 April 1920
May
102.9 mm (4.1 in)
7 May 2003
Jun
116.1 mm (4.6 in)
21 June 1961
Jul
137.7 mm (5.4 in)
14 July 1990
Aug
98.8 mm (3.9 in)
27 August 1976
Sep
119.9 mm (4.7 in)
17 September 2004
Oct
115.8 mm (4.6 in)
31 October 1949
Nov
100.3 mm (3.9 in)
24 November 2004
Dec
114.3 mm (4.5 in)
21 December 1918
Period of Record Coverage
1914 to 2009
Complete yearUnder 90 percent of days
96 years of record at Copperhill, 1914 to 2009. 24 years have data for under 90 percent of days and are left out of rankings: 1914, 1919, 1921, 1987, 1988, 1989, 1990, 1992 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 69 complete years at Copperhill, 1915 to 1995. Blue stripes are years cooler than the station's own mean of 14.0 C (57.2 F); red stripes are warmer. The coolest year was 1976, at 12.9 C (55.2 F), and the warmest was 1915, at 15.8 C (60.4 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Copperhill as warming stripes, 1915 to 1995
Year
Annual mean temperature
Difference from the station mean
1915
15.8 C
+1.77 C
1916
15.7 C
+1.67 C
1917
14.2 C
+0.15 C
1923
15.0 C
+1.02 C
1925
14.8 C
+0.75 C
1926
14.1 C
+0.14 C
1927
15.1 C
+1.08 C
1928
13.6 C
-0.36 C
1929
14.3 C
+0.29 C
1931
14.8 C
+0.77 C
1932
14.5 C
+0.53 C
1933
14.9 C
+0.92 C
1934
14.2 C
+0.21 C
1935
14.5 C
+0.49 C
1936
14.6 C
+0.61 C
1937
14.1 C
+0.10 C
1938
14.7 C
+0.71 C
1939
14.5 C
+0.54 C
1940
13.0 C
-1.00 C
1941
14.3 C
+0.31 C
1942
13.6 C
-0.43 C
1943
13.2 C
-0.76 C
1944
14.0 C
-0.02 C
1945
14.3 C
+0.26 C
1946
14.5 C
+0.49 C
1947
13.7 C
-0.35 C
1948
14.2 C
+0.24 C
1949
14.7 C
+0.74 C
1950
14.0 C
+0.00 C
1951
13.8 C
-0.23 C
1952
14.2 C
+0.15 C
1953
13.9 C
-0.06 C
1954
13.9 C
-0.12 C
1955
13.8 C
-0.18 C
1956
14.3 C
+0.27 C
1957
14.5 C
+0.51 C
1958
13.0 C
-0.98 C
1959
14.2 C
+0.15 C
1960
13.1 C
-0.88 C
1961
13.4 C
-0.60 C
1962
13.6 C
-0.41 C
1963
12.9 C
-1.09 C
1964
13.7 C
-0.28 C
1965
14.1 C
+0.13 C
1966
13.3 C
-0.72 C
1967
13.6 C
-0.37 C
1968
13.1 C
-0.90 C
1969
13.4 C
-0.65 C
1970
13.9 C
-0.13 C
1971
14.1 C
+0.05 C
1972
13.7 C
-0.28 C
1973
14.2 C
+0.21 C
1974
14.4 C
+0.43 C
1975
14.4 C
+0.37 C
1976
12.9 C
-1.10 C
1977
13.9 C
-0.13 C
1978
13.6 C
-0.38 C
1979
13.4 C
-0.56 C
1980
13.9 C
-0.06 C
1981
13.4 C
-0.60 C
1982
14.3 C
+0.33 C
1983
13.6 C
-0.41 C
1984
14.2 C
+0.17 C
1985
13.9 C
-0.14 C
1989
13.2 C
-0.82 C
1991
14.2 C
+0.18 C
1992
13.3 C
-0.72 C
1993
13.7 C
-0.33 C
1995
13.3 C
-0.75 C
The annual mean temperature here has fallen by 0.2 C (0.1 to 0.2) per decade over 1915 to 1995. In Fahrenheit: 0.3 F (0.2 to 0.4) per decade. The slope is a straight line fitted to 69 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Copperhill
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.2 C (-0.2 to -0.1) per decade
-0.3 F (-0.4 to -0.2) per decade
1915 to 1995
69
Fall
Mean daily maximum
-0.05 C (-0.11 to 0.00) per decade
-0.10 F (-0.20 to 0.01) per decade
1915 to 1995
69
Not clearly different from zero
Mean daily minimum
-0.3 C (-0.4 to -0.2) per decade
-0.5 F (-0.6 to -0.4) per decade
1915 to 1995
69
Fall
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
1914 to 2009
Yearly extremes at Copperhill: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
39.4 C (102.9 F)
1919
35.6 C (96.1 F)
96
Coldest night (TNn)
-27.2 C (-17.0 F)
1983
-14.4 C (6.1 F)
96
Wettest day (Rx1day)
137.7 mm (5.4 in)
1990
73.1 mm (2.9 in)
96
Wettest five days (Rx5day)
224.5 mm (8.8 in)
1938
120.1 mm (4.7 in)
96
Longest dry spell (CDD)
40 days
1939
18 days
96
Hottest day (TXx)
The hottest day of the year at Copperhill, 1914 to 2009. The record is 39.4 C (102.9 F) in 1919, marked on the chart; the median year is 35.6 C (96.1 F).
Hottest day (TXx) at Copperhill by year
Year
Hottest day (TXx)
1914
37.2 C (99.0 F)
1915
37.8 C (100.0 F)
1916
37.2 C (99.0 F)
1917
35.6 C (96.1 F)
1918
35.6 C (96.1 F)
1919
39.4 C (102.9 F)
1920
36.7 C (98.1 F)
1921
35.6 C (96.1 F)
1922
35.0 C (95.0 F)
1923
34.4 C (93.9 F)
1924
36.7 C (98.1 F)
1925
38.3 C (100.9 F)
1926
38.3 C (100.9 F)
1927
35.0 C (95.0 F)
1928
34.4 C (93.9 F)
1929
33.9 C (93.0 F)
1930
38.3 C (100.9 F)
1931
37.8 C (100.0 F)
1932
35.6 C (96.1 F)
1933
37.2 C (99.0 F)
1934
38.3 C (100.9 F)
1935
37.2 C (99.0 F)
1936
38.3 C (100.9 F)
1937
35.6 C (96.1 F)
1938
35.0 C (95.0 F)
1939
36.1 C (97.0 F)
1940
35.6 C (96.1 F)
1941
35.6 C (96.1 F)
1942
35.0 C (95.0 F)
1943
36.1 C (97.0 F)
1944
37.2 C (99.0 F)
1945
36.1 C (97.0 F)
1946
33.3 C (91.9 F)
1947
35.6 C (96.1 F)
1948
36.1 C (97.0 F)
1949
35.0 C (95.0 F)
1950
33.3 C (91.9 F)
1951
35.6 C (96.1 F)
1952
39.4 C (102.9 F)
1953
36.1 C (97.0 F)
1954
36.7 C (98.1 F)
1955
35.0 C (95.0 F)
1956
36.7 C (98.1 F)
1957
37.2 C (99.0 F)
1958
36.1 C (97.0 F)
1959
36.1 C (97.0 F)
1960
35.0 C (95.0 F)
1961
33.9 C (93.0 F)
1962
35.0 C (95.0 F)
1963
34.4 C (93.9 F)
1964
37.8 C (100.0 F)
1965
36.1 C (97.0 F)
1966
37.2 C (99.0 F)
1967
34.4 C (93.9 F)
1968
38.3 C (100.9 F)
1969
37.2 C (99.0 F)
1970
36.1 C (97.0 F)
1971
36.1 C (97.0 F)
1972
34.4 C (93.9 F)
1973
33.3 C (91.9 F)
1974
32.2 C (90.0 F)
1975
36.7 C (98.1 F)
1976
35.0 C (95.0 F)
1977
37.8 C (100.0 F)
1978
36.7 C (98.1 F)
1979
35.6 C (96.1 F)
1980
38.9 C (102.0 F)
1981
36.1 C (97.0 F)
1982
35.0 C (95.0 F)
1983
37.8 C (100.0 F)
1984
34.4 C (93.9 F)
1985
35.0 C (95.0 F)
1986
37.2 C (99.0 F)
1987
31.1 C (88.0 F)
1988
35.0 C (95.0 F)
1989
32.8 C (91.0 F)
1990
34.4 C (93.9 F)
1991
33.3 C (91.9 F)
1992
33.3 C (91.9 F)
1993
37.2 C (99.0 F)
1994
32.2 C (90.0 F)
1995
35.6 C (96.1 F)
1996
32.8 C (91.0 F)
1997
35.6 C (96.1 F)
1998
35.0 C (95.0 F)
1999
35.0 C (95.0 F)
2000
35.6 C (96.1 F)
2001
31.7 C (89.1 F)
2002
33.9 C (93.0 F)
2003
32.8 C (91.0 F)
2004
32.8 C (91.0 F)
2005
35.0 C (95.0 F)
2006
34.4 C (93.9 F)
2007
37.2 C (99.0 F)
2008
34.4 C (93.9 F)
2009
18.3 C (64.9 F)
Coldest night (TNn)
The coldest night of the year at Copperhill, 1914 to 2009. The record is -27.2 C (-17.0 F) in 1983, marked on the chart; the median year is -14.4 C (6.1 F).
Coldest night (TNn) at Copperhill by year
Year
Coldest night (TNn)
1914
-14.4 C (6.1 F)
1915
-8.9 C (16.0 F)
1916
-12.2 C (10.0 F)
1917
-18.9 C (-2.0 F)
1918
-16.7 C (1.9 F)
1919
-17.8 C (0.0 F)
1920
-14.4 C (6.1 F)
1921
-6.7 C (19.9 F)
1922
-9.4 C (15.1 F)
1923
-13.3 C (8.1 F)
1924
-19.4 C (-2.9 F)
1925
-17.8 C (0.0 F)
1926
-11.1 C (12.0 F)
1927
-15.6 C (3.9 F)
1928
-19.4 C (-2.9 F)
1929
-13.3 C (8.1 F)
1930
-13.3 C (8.1 F)
1931
-11.1 C (12.0 F)
1932
-10.6 C (12.9 F)
1933
-17.8 C (0.0 F)
1934
-16.7 C (1.9 F)
1935
-13.3 C (8.1 F)
1936
-18.9 C (-2.0 F)
1937
-13.3 C (8.1 F)
1938
-11.1 C (12.0 F)
1939
-10.0 C (14.0 F)
1940
-24.4 C (-11.9 F)
1941
-10.6 C (12.9 F)
1942
-16.1 C (3.0 F)
1943
-15.0 C (5.0 F)
1944
-12.8 C (9.0 F)
1945
-12.2 C (10.0 F)
1946
-11.7 C (10.9 F)
1947
-13.3 C (8.1 F)
1948
-18.9 C (-2.0 F)
1949
-8.3 C (17.1 F)
1950
-18.3 C (-0.9 F)
1951
-16.7 C (1.9 F)
1952
-12.2 C (10.0 F)
1953
-14.4 C (6.1 F)
1954
-12.8 C (9.0 F)
1955
-13.9 C (7.0 F)
1956
-10.6 C (12.9 F)
1957
-17.2 C (1.0 F)
1958
-19.4 C (-2.9 F)
1959
-14.4 C (6.1 F)
1960
-15.0 C (5.0 F)
1961
-17.8 C (0.0 F)
1962
-21.1 C (-6.0 F)
1963
-22.2 C (-8.0 F)
1964
-17.2 C (1.0 F)
1965
-13.3 C (8.1 F)
1966
-22.2 C (-8.0 F)
1967
-16.1 C (3.0 F)
1968
-12.8 C (9.0 F)
1969
-16.1 C (3.0 F)
1970
-20.6 C (-5.1 F)
1971
-14.4 C (6.1 F)
1972
-20.0 C (-4.0 F)
1973
-12.8 C (9.0 F)
1974
-9.4 C (15.1 F)
1975
-12.8 C (9.0 F)
1976
-15.0 C (5.0 F)
1977
-20.0 C (-4.0 F)
1978
-15.0 C (5.0 F)
1979
-15.0 C (5.0 F)
1980
-13.3 C (8.1 F)
1981
-16.1 C (3.0 F)
1982
-21.7 C (-7.1 F)
1983
-27.2 C (-17.0 F)
1984
-15.0 C (5.0 F)
1985
-26.7 C (-16.1 F)
1986
-11.1 C (12.0 F)
1987
-13.9 C (7.0 F)
1988
-11.1 C (12.0 F)
1989
-22.2 C (-8.0 F)
1990
-11.7 C (10.9 F)
1991
-14.4 C (6.1 F)
1992
-13.3 C (8.1 F)
1993
-12.2 C (10.0 F)
1994
-23.9 C (-11.0 F)
1995
-17.2 C (1.0 F)
1996
-20.6 C (-5.1 F)
1997
-14.4 C (6.1 F)
1998
-13.3 C (8.1 F)
1999
-14.4 C (6.1 F)
2000
-15.0 C (5.0 F)
2001
-15.0 C (5.0 F)
2002
-14.4 C (6.1 F)
2003
-18.9 C (-2.0 F)
2004
-12.2 C (10.0 F)
2005
-15.0 C (5.0 F)
2006
-12.8 C (9.0 F)
2007
-12.8 C (9.0 F)
2008
-15.0 C (5.0 F)
2009
-15.6 C (3.9 F)
Wettest day (Rx1day)
The wettest day of the year at Copperhill, 1914 to 2009. The record is 137.7 mm (5.4 in) in 1990, marked on the chart; the median year is 73.1 mm (2.9 in).
Wettest day (Rx1day) at Copperhill by year
Year
Wettest day (Rx1day)
1914
78.5 mm (3.1 in)
1915
61.7 mm (2.4 in)
1916
45.0 mm (1.8 in)
1917
58.4 mm (2.3 in)
1918
114.3 mm (4.5 in)
1919
100.8 mm (4.0 in)
1920
135.1 mm (5.3 in)
1921
54.9 mm (2.2 in)
1922
68.6 mm (2.7 in)
1923
54.4 mm (2.1 in)
1924
82.3 mm (3.2 in)
1925
49.8 mm (2.0 in)
1926
64.8 mm (2.6 in)
1927
53.6 mm (2.1 in)
1928
69.9 mm (2.8 in)
1929
78.2 mm (3.1 in)
1930
55.9 mm (2.2 in)
1931
82.6 mm (3.3 in)
1932
72.4 mm (2.9 in)
1933
63.5 mm (2.5 in)
1934
86.4 mm (3.4 in)
1935
50.3 mm (2.0 in)
1936
101.9 mm (4.0 in)
1937
50.8 mm (2.0 in)
1938
67.8 mm (2.7 in)
1939
44.5 mm (1.8 in)
1940
43.2 mm (1.7 in)
1941
55.4 mm (2.2 in)
1942
76.2 mm (3.0 in)
1943
64.0 mm (2.5 in)
1944
71.1 mm (2.8 in)
1945
78.0 mm (3.1 in)
1946
91.9 mm (3.6 in)
1947
80.5 mm (3.2 in)
1948
76.7 mm (3.0 in)
1949
115.8 mm (4.6 in)
1950
102.9 mm (4.1 in)
1951
133.1 mm (5.2 in)
1952
102.9 mm (4.1 in)
1953
64.5 mm (2.5 in)
1954
73.7 mm (2.9 in)
1955
72.4 mm (2.9 in)
1956
79.5 mm (3.1 in)
1957
88.9 mm (3.5 in)
1958
105.7 mm (4.2 in)
1959
65.5 mm (2.6 in)
1960
67.6 mm (2.7 in)
1961
116.1 mm (4.6 in)
1962
86.4 mm (3.4 in)
1963
85.6 mm (3.4 in)
1964
111.3 mm (4.4 in)
1965
60.2 mm (2.4 in)
1966
71.6 mm (2.8 in)
1967
78.2 mm (3.1 in)
1968
37.6 mm (1.5 in)
1969
75.9 mm (3.0 in)
1970
73.7 mm (2.9 in)
1971
48.0 mm (1.9 in)
1972
55.9 mm (2.2 in)
1973
83.1 mm (3.3 in)
1974
59.4 mm (2.3 in)
1975
97.8 mm (3.9 in)
1976
99.6 mm (3.9 in)
1977
80.8 mm (3.2 in)
1978
46.2 mm (1.8 in)
1979
118.1 mm (4.6 in)
1980
98.0 mm (3.9 in)
1981
60.2 mm (2.4 in)
1982
83.6 mm (3.3 in)
1983
62.7 mm (2.5 in)
1984
58.4 mm (2.3 in)
1985
48.0 mm (1.9 in)
1986
73.7 mm (2.9 in)
1987
61.0 mm (2.4 in)
1988
70.9 mm (2.8 in)
1989
59.9 mm (2.4 in)
1990
137.7 mm (5.4 in)
1991
66.8 mm (2.6 in)
1992
75.7 mm (3.0 in)
1993
80.3 mm (3.2 in)
1994
101.6 mm (4.0 in)
1995
82.8 mm (3.3 in)
1996
102.6 mm (4.0 in)
1997
108.0 mm (4.3 in)
1998
67.1 mm (2.6 in)
1999
70.6 mm (2.8 in)
2000
78.2 mm (3.1 in)
2001
62.0 mm (2.4 in)
2002
91.9 mm (3.6 in)
2003
102.9 mm (4.1 in)
2004
119.9 mm (4.7 in)
2005
41.9 mm (1.6 in)
2006
47.2 mm (1.9 in)
2007
45.2 mm (1.8 in)
2008
69.6 mm (2.7 in)
2009
58.4 mm (2.3 in)
Wettest five days (Rx5day)
The wettest five days of the year at Copperhill, 1914 to 2009. The record is 224.5 mm (8.8 in) in 1938, marked on the chart; the median year is 120.1 mm (4.7 in).
Wettest five days (Rx5day) at Copperhill by year
Year
Wettest five days (Rx5day)
1914
116.2 mm (4.6 in)
1915
71.1 mm (2.8 in)
1916
118.4 mm (4.7 in)
1917
177.8 mm (7.0 in)
1918
141.6 mm (5.6 in)
1919
141.4 mm (5.6 in)
1920
200.1 mm (7.9 in)
1921
114.8 mm (4.5 in)
1922
147.9 mm (5.8 in)
1923
98.5 mm (3.9 in)
1924
137.3 mm (5.4 in)
1925
94.9 mm (3.7 in)
1926
139.2 mm (5.5 in)
1927
113.8 mm (4.5 in)
1928
152.9 mm (6.0 in)
1929
121.5 mm (4.8 in)
1930
83.1 mm (3.3 in)
1931
110.2 mm (4.3 in)
1932
131.0 mm (5.2 in)
1933
99.3 mm (3.9 in)
1934
125.2 mm (4.9 in)
1935
103.4 mm (4.1 in)
1936
201.7 mm (7.9 in)
1937
128.5 mm (5.1 in)
1938
224.5 mm (8.8 in)
1939
97.4 mm (3.8 in)
1940
58.9 mm (2.3 in)
1941
98.8 mm (3.9 in)
1942
116.9 mm (4.6 in)
1943
107.5 mm (4.2 in)
1944
165.4 mm (6.5 in)
1945
97.8 mm (3.9 in)
1946
152.4 mm (6.0 in)
1947
169.1 mm (6.7 in)
1948
154.0 mm (6.1 in)
1949
152.0 mm (6.0 in)
1950
133.6 mm (5.3 in)
1951
160.0 mm (6.3 in)
1952
117.4 mm (4.6 in)
1953
91.7 mm (3.6 in)
1954
127.2 mm (5.0 in)
1955
100.9 mm (4.0 in)
1956
128.3 mm (5.1 in)
1957
144.8 mm (5.7 in)
1958
189.2 mm (7.4 in)
1959
111.6 mm (4.4 in)
1960
130.5 mm (5.1 in)
1961
187.8 mm (7.4 in)
1962
145.8 mm (5.7 in)
1963
140.5 mm (5.5 in)
1964
155.5 mm (6.1 in)
1965
146.3 mm (5.8 in)
1966
121.6 mm (4.8 in)
1967
159.0 mm (6.3 in)
1968
75.9 mm (3.0 in)
1969
115.3 mm (4.5 in)
1970
121.7 mm (4.8 in)
1971
96.5 mm (3.8 in)
1972
102.8 mm (4.0 in)
1973
144.1 mm (5.7 in)
1974
100.5 mm (4.0 in)
1975
130.8 mm (5.1 in)
1976
118.7 mm (4.7 in)
1977
142.1 mm (5.6 in)
1978
75.2 mm (3.0 in)
1979
123.2 mm (4.9 in)
1980
167.4 mm (6.6 in)
1981
69.4 mm (2.7 in)
1982
144.2 mm (5.7 in)
1983
108.0 mm (4.3 in)
1984
102.1 mm (4.0 in)
1985
102.8 mm (4.0 in)
1986
88.4 mm (3.5 in)
1987
100.6 mm (4.0 in)
1988
83.9 mm (3.3 in)
1989
172.9 mm (6.8 in)
1990
223.6 mm (8.8 in)
1991
115.5 mm (4.5 in)
1992
96.2 mm (3.8 in)
1993
160.3 mm (6.3 in)
1994
184.4 mm (7.3 in)
1995
109.6 mm (4.3 in)
1996
122.2 mm (4.8 in)
1997
121.7 mm (4.8 in)
1998
89.5 mm (3.5 in)
1999
84.3 mm (3.3 in)
2000
138.2 mm (5.4 in)
2001
75.4 mm (3.0 in)
2002
170.4 mm (6.7 in)
2003
85.9 mm (3.4 in)
2004
83.4 mm (3.3 in)
2005
46.6 mm (1.8 in)
2006
96.0 mm (3.8 in)
2007
55.9 mm (2.2 in)
2008
114.1 mm (4.5 in)
2009
0.0 mm (0.00 in)
Longest dry spell (CDD)
The longest dry spell of the year at Copperhill, 1914 to 2009. The record is 40 days in 1939, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Copperhill by year
Year
Longest dry spell (CDD)
1914
28 days
1915
20 days
1916
13 days
1917
13 days
1918
12 days
1919
14 days
1920
31 days
1921
25 days
1922
15 days
1923
27 days
1924
25 days
1925
28 days
1926
21 days
1927
20 days
1928
17 days
1929
15 days
1930
22 days
1931
38 days
1932
16 days
1933
26 days
1934
19 days
1935
38 days
1936
21 days
1937
8 days
1938
35 days
1939
40 days
1940
13 days
1941
19 days
1942
20 days
1943
25 days
1944
21 days
1945
16 days
1946
15 days
1947
13 days
1948
19 days
1949
12 days
1950
19 days
1951
22 days
1952
30 days
1953
22 days
1954
22 days
1955
24 days
1956
18 days
1957
14 days
1958
17 days
1959
20 days
1960
13 days
1961
12 days
1962
22 days
1963
33 days
1964
20 days
1965
18 days
1966
11 days
1967
19 days
1968
17 days
1969
17 days
1970
21 days
1971
14 days
1972
10 days
1973
26 days
1974
20 days
1975
9 days
1976
16 days
1977
19 days
1978
24 days
1979
16 days
1980
18 days
1981
15 days
1982
12 days
1983
18 days
1984
25 days
1985
18 days
1986
21 days
1987
15 days
1988
15 days
1989
17 days
1990
13 days
1991
18 days
1992
18 days
1993
17 days
1994
11 days
1995
16 days
1996
16 days
1997
14 days
1998
20 days
1999
20 days
2000
36 days
2001
24 days
2002
15 days
2003
9 days
2004
11 days
2005
11 days
2006
15 days
2007
15 days
2008
22 days
2009
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
69 years with a frost
Across 69 years with a frost, the median last spring frost at Copperhill falls on 16 April and the median first autumn frost on 19 October, which leaves a median of 188 days between them.
In 1961 to 1995 the median growing season was 178 days. That is 19 days fewer than in 1915 to 1951.
Fitted over all years, the growing season changes by -4.4 days per decade at this station.
Frost dates and growing season at Copperhill
Measure
Median, all years
Earliest period (1915 to 1951)
Recent period (1961 to 1995)
Recent against earliest
Fitted trend
Last spring frost
16 April
13 April
24 April
11 days later
+2.7 days per decade
First autumn frost
19 October
25 October
17 October
8 days earlier
-1.7 days per decade
Growing days
188 days
197 days
178 days
19 days fewer
-4.4 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
72 years, 1919 to 1995
A day with at least 73.5 mm (2.9 in) of rain is expected about once in 2 years. A day with at least 146.0 mm (5.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Copperhill: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
73.5 mm (2.9 in)
5 years
93.9 mm (3.7 in)
10 years
107.0 mm (4.2 in)
25 years
123.1 mm (4.8 in)
50 years
134.8 mm (5.3 in)
100 years
146.0 mm (5.7 in)
Longer than the 72 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, 72 years of values from 1919 to 1995.
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: 137.7 mm (5.4 in) in 1990; 135.1 mm (5.3 in) in 1920; 133.1 mm (5.2 in) in 1951.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Copperhill standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Copperhill 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.