Record envelope, standing records and threshold days for Green Mt Dam (USC00053592), Colorado, United States, with 82 years of record.
Key Facts for Green Mt Dam
Green Mt Dam (USC00053592) is a weather station in Colorado, United States at 39.88 latitude and -106.33 longitude, 2,359 m (7,740 ft) above sea level.
The station reports from 1939 to 2020, 82 years of record.
1,464 records set at Green Mt Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Green Mt Dam tied a daily record snowfall of 12.7 cm (5.0 in) on 16 April 2020.
About the Station
Location: Colorado, United States, 39.88 latitude, -106.33 longitude.
Elevation: 2,359 m (7,740 ft).
Period of record: 1939 to 2020, 82 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 Green Mt Dam. 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 Green Mt Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
15.6 C (60.1 F)
-40.6 C (-41.1 F)
n/a
n/a
Feb
14.4 C (57.9 F)
-43.3 C (-45.9 F)
n/a
n/a
Mar
19.4 C (66.9 F)
-32.2 C (-26.0 F)
n/a
n/a
Apr
25.0 C (77.0 F)
-23.9 C (-11.0 F)
n/a
n/a
May
30.0 C (86.0 F)
-13.9 C (7.0 F)
n/a
n/a
Jun
35.0 C (95.0 F)
-6.1 C (21.0 F)
n/a
n/a
Jul
36.1 C (97.0 F)
-4.4 C (24.1 F)
n/a
n/a
Aug
33.9 C (93.0 F)
-4.4 C (24.1 F)
n/a
n/a
Sep
35.0 C (95.0 F)
-10.6 C (12.9 F)
n/a
n/a
Oct
28.9 C (84.0 F)
-17.2 C (1.0 F)
n/a
n/a
Nov
19.4 C (66.9 F)
-27.2 C (-17.0 F)
n/a
n/a
Dec
16.7 C (62.1 F)
-32.2 C (-26.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Green Mt Dam still stand. 1954 holds the most, with 65.
Standing records at Green Mt Dam by the year they were set
Year set
Standing records
1939
22
1940
23
1941
18
1942
24
1943
19
1944
12
1945
28
1946
35
1947
22
1948
27
1949
19
1950
25
1951
27
1952
47
1953
26
1954
65
1955
31
1956
33
1957
23
1958
21
1959
28
1960
26
1961
14
1962
37
1963
33
1964
26
1965
27
1966
13
1967
20
1968
5
1969
22
1970
12
1971
18
1972
24
1973
13
1974
8
1975
16
1976
10
1977
12
1978
22
1979
25
1980
50
1981
30
1982
23
1983
11
1984
17
1985
11
1986
15
1987
12
1988
12
1989
23
1990
18
1991
12
1992
12
1993
34
1994
7
1995
21
1996
18
1997
10
1998
8
1999
15
2000
17
2001
12
2002
7
2003
8
2004
23
2005
17
2006
33
2007
11
2008
19
All-Time Record Progression
6 new records
6 all-time records were set at Green Mt Dam between 28 January 1980 and 29 August 2000. Each dot is a new record.
When Green Mt Dam set new all-time records
Date
Kind
Detail
1980-01-28
Record daily snowfall
Record daily snowfall 55.9 cm (22.0 in)
1985-11-08
Record daily precipitation
Record daily precipitation 39.4 mm (1.6 in)
1985-11-08
Record daily snowfall
Record daily snowfall 61.0 cm (24.0 in)
1989-02-07
Record low minimum temperature
Record low minimum temperature -43.3 C (-45.9 F)
2000-04-23
Record daily precipitation
Record daily precipitation 40.6 mm (1.6 in)
2000-08-29
Record daily precipitation
Record daily precipitation 63.5 mm (2.5 in)
Wettest Day of Each Month
Aug: 63.5 mm (2.5 in)
The wettest day on record for each calendar month at Green Mt Dam. The most was 63.5 mm (2.5 in) on 29 August 2000.
Record daily precipitation for each month at Green Mt Dam
Month
Record daily precipitation (mm)
Date
Jan
28.2 mm (1.1 in)
29 January 1951
Feb
32.8 mm (1.3 in)
21 February 1996
Mar
26.7 mm (1.1 in)
23 March 2003
Apr
40.6 mm (1.6 in)
23 April 2000
May
33.3 mm (1.3 in)
5 May 1960
Jun
35.6 mm (1.4 in)
16 June 1963
Jul
38.6 mm (1.5 in)
3 July 1995
Aug
63.5 mm (2.5 in)
29 August 2000
Sep
38.1 mm (1.5 in)
27 September 1959
Oct
38.1 mm (1.5 in)
7 October 1970
Nov
39.4 mm (1.6 in)
8 November 1985
Dec
30.5 mm (1.2 in)
6 December 1966
Period of Record Coverage
1939 to 2008
Complete yearUnder 90 percent of days
70 years of record at Green Mt Dam, 1939 to 2008. 6 years have data for under 90 percent of days and are left out of rankings: 1939, 1986, 1995, 1998, 2007, 2008.
Cooler than the station meanWarmer than the station mean
One stripe for each of 61 complete years at Green Mt Dam, 1940 to 2006. Blue stripes are years cooler than the station's own mean of 4.2 C (39.5 F); red stripes are warmer. The coolest year was 2006, at 1.3 C (34.3 F), and the warmest was 1954, at 7.0 C (44.5 F). The strongest colour marks a difference of 2.9 C (5.2 F).
Annual mean temperature at Green Mt Dam as warming stripes, 1940 to 2006
Year
Annual mean temperature
Difference from the station mean
1940
5.0 C
+0.80 C
1941
4.2 C
+0.02 C
1942
2.9 C
-1.24 C
1943
4.6 C
+0.41 C
1944
4.2 C
-0.01 C
1945
4.3 C
+0.16 C
1946
4.9 C
+0.71 C
1947
4.6 C
+0.39 C
1948
3.6 C
-0.55 C
1949
3.8 C
-0.35 C
1950
4.2 C
+0.04 C
1951
3.9 C
-0.28 C
1952
3.1 C
-1.11 C
1953
5.2 C
+1.00 C
1954
7.0 C
+2.80 C
1955
4.5 C
+0.31 C
1956
5.0 C
+0.80 C
1957
4.6 C
+0.46 C
1958
5.6 C
+1.44 C
1959
4.9 C
+0.77 C
1960
5.4 C
+1.26 C
1961
4.7 C
+0.52 C
1962
4.7 C
+0.56 C
1963
6.3 C
+2.10 C
1964
3.8 C
-0.38 C
1965
4.1 C
-0.03 C
1966
4.7 C
+0.51 C
1967
4.8 C
+0.66 C
1968
3.7 C
-0.46 C
1969
4.8 C
+0.58 C
1970
4.5 C
+0.30 C
1971
4.7 C
+0.55 C
1972
4.9 C
+0.74 C
1973
3.2 C
-0.97 C
1974
4.0 C
-0.16 C
1975
4.0 C
-0.13 C
1976
4.1 C
-0.07 C
1977
5.7 C
+1.54 C
1978
5.0 C
+0.87 C
1979
3.8 C
-0.35 C
1981
6.2 C
+2.00 C
1982
3.7 C
-0.49 C
1983
3.9 C
-0.23 C
1984
2.1 C
-2.03 C
1988
2.8 C
-1.42 C
1989
2.6 C
-1.55 C
1990
3.5 C
-0.72 C
1991
4.7 C
+0.51 C
1992
4.6 C
+0.47 C
1993
1.3 C
-2.86 C
1994
4.2 C
+0.06 C
1996
3.8 C
-0.34 C
1997
3.5 C
-0.72 C
1999
4.0 C
-0.21 C
2000
4.4 C
+0.26 C
2001
3.9 C
-0.24 C
2002
3.4 C
-0.80 C
2003
3.7 C
-0.44 C
2004
3.0 C
-1.13 C
2005
2.9 C
-1.23 C
2006
1.3 C
-2.87 C
The annual mean temperature here has fallen by 0.2 C (0.1 to 0.3) per decade over 1940 to 2006. In Fahrenheit: 0.4 F (0.2 to 0.6) per decade. The slope is a straight line fitted to 61 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Green Mt Dam
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.2 C (-0.3 to -0.1) per decade
-0.4 F (-0.6 to -0.2) per decade
1940 to 2006
61
Fall
Mean daily maximum
-0.4 C (-0.6 to -0.3) per decade
-0.8 F (-1.0 to -0.5) per decade
1940 to 2006
61
Fall
Mean daily minimum
0.00 C (-0.14 to 0.13) per decade
-0.01 F (-0.24 to 0.23) per decade
1940 to 2006
61
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
1939 to 2020
Yearly extremes at Green Mt Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.1 C (97.0 F)
1954
31.1 C (88.0 F)
70
Coldest night (TNn)
-43.3 C (-45.9 F)
1989
-30.6 C (-23.1 F)
70
Wettest day (Rx1day)
63.5 mm (2.5 in)
2000
21.7 mm (0.9 in)
82
Wettest five days (Rx5day)
90.4 mm (3.6 in)
2000
34.3 mm (1.4 in)
75
Longest dry spell (CDD)
54 days
1979
22 days
82
Hottest day (TXx)
The hottest day of the year at Green Mt Dam, 1939 to 2020. The record is 36.1 C (97.0 F) in 1954, marked on the chart; the median year is 31.1 C (88.0 F).
Hottest day (TXx) at Green Mt Dam by year
Year
Hottest day (TXx)
1939
34.4 C (93.9 F)
1940
31.7 C (89.1 F)
1941
30.6 C (87.1 F)
1942
31.1 C (88.0 F)
1943
29.4 C (84.9 F)
1944
31.1 C (88.0 F)
1945
34.4 C (93.9 F)
1946
31.7 C (89.1 F)
1947
32.8 C (91.0 F)
1948
29.4 C (84.9 F)
1949
28.3 C (82.9 F)
1950
28.3 C (82.9 F)
1951
33.3 C (91.9 F)
1952
35.0 C (95.0 F)
1953
33.3 C (91.9 F)
1954
36.1 C (97.0 F)
1955
30.0 C (86.0 F)
1956
34.4 C (93.9 F)
1957
31.1 C (88.0 F)
1958
32.2 C (90.0 F)
1959
32.2 C (90.0 F)
1960
32.2 C (90.0 F)
1961
31.1 C (88.0 F)
1962
31.7 C (89.1 F)
1963
32.8 C (91.0 F)
1964
32.8 C (91.0 F)
1965
29.4 C (84.9 F)
1966
31.1 C (88.0 F)
1967
30.0 C (86.0 F)
1968
29.4 C (84.9 F)
1969
31.7 C (89.1 F)
1970
31.1 C (88.0 F)
1971
31.1 C (88.0 F)
1972
30.0 C (86.0 F)
1973
31.1 C (88.0 F)
1974
30.0 C (86.0 F)
1975
30.0 C (86.0 F)
1976
31.7 C (89.1 F)
1977
30.6 C (87.1 F)
1978
30.6 C (87.1 F)
1979
32.8 C (91.0 F)
1980
31.7 C (89.1 F)
1981
31.1 C (88.0 F)
1982
31.1 C (88.0 F)
1983
30.6 C (87.1 F)
1984
27.8 C (82.0 F)
1985
30.6 C (87.1 F)
1986
28.9 C (84.0 F)
1987
32.8 C (91.0 F)
1988
31.1 C (88.0 F)
1989
31.7 C (89.1 F)
1990
30.6 C (87.1 F)
1991
31.1 C (88.0 F)
1992
30.0 C (86.0 F)
1993
27.8 C (82.0 F)
1994
31.7 C (89.1 F)
1995
31.7 C (89.1 F)
1996
31.7 C (89.1 F)
1997
30.0 C (86.0 F)
1998
25.0 C (77.0 F)
1999
30.6 C (87.1 F)
2000
30.6 C (87.1 F)
2001
31.1 C (88.0 F)
2002
32.2 C (90.0 F)
2003
33.3 C (91.9 F)
2004
31.7 C (89.1 F)
2005
32.8 C (91.0 F)
2006
29.4 C (84.9 F)
2007
21.1 C (70.0 F)
2008
33.3 C (91.9 F)
2009
n/a
2010
n/a
2011
n/a
2012
n/a
2013
n/a
2014
n/a
2015
n/a
2016
n/a
2017
n/a
2018
n/a
2019
n/a
2020
n/a
Coldest night (TNn)
The coldest night of the year at Green Mt Dam, 1939 to 2020. The record is -43.3 C (-45.9 F) in 1989, marked on the chart; the median year is -30.6 C (-23.1 F).
Coldest night (TNn) at Green Mt Dam by year
Year
Coldest night (TNn)
1939
-22.8 C (-9.0 F)
1940
-40.0 C (-40.0 F)
1941
-28.9 C (-20.0 F)
1942
-40.0 C (-40.0 F)
1943
-32.8 C (-27.0 F)
1944
-31.1 C (-24.0 F)
1945
-26.7 C (-16.1 F)
1946
-29.4 C (-20.9 F)
1947
-31.7 C (-25.1 F)
1948
-38.3 C (-36.9 F)
1949
-32.2 C (-26.0 F)
1950
-32.2 C (-26.0 F)
1951
-42.2 C (-44.0 F)
1952
-38.9 C (-38.0 F)
1953
-28.3 C (-18.9 F)
1954
-28.9 C (-20.0 F)
1955
-30.6 C (-23.1 F)
1956
-32.8 C (-27.0 F)
1957
-33.3 C (-27.9 F)
1958
-27.8 C (-18.0 F)
1959
-28.3 C (-18.9 F)
1960
-28.9 C (-20.0 F)
1961
-29.4 C (-20.9 F)
1962
-40.6 C (-41.1 F)
1963
-40.6 C (-41.1 F)
1964
-33.9 C (-29.0 F)
1965
-28.9 C (-20.0 F)
1966
-29.4 C (-20.9 F)
1967
-30.0 C (-22.0 F)
1968
-26.1 C (-15.0 F)
1969
-31.7 C (-25.1 F)
1970
-30.6 C (-23.1 F)
1971
-32.8 C (-27.0 F)
1972
-32.8 C (-27.0 F)
1973
-31.1 C (-24.0 F)
1974
-35.0 C (-31.0 F)
1975
-31.1 C (-24.0 F)
1976
-28.9 C (-20.0 F)
1977
-25.0 C (-13.0 F)
1978
-30.6 C (-23.1 F)
1979
-33.3 C (-27.9 F)
1980
-32.2 C (-26.0 F)
1981
-23.9 C (-11.0 F)
1982
-34.4 C (-29.9 F)
1983
-25.6 C (-14.1 F)
1984
-30.0 C (-22.0 F)
1985
-31.1 C (-24.0 F)
1986
-28.9 C (-20.0 F)
1987
-23.3 C (-9.9 F)
1988
-35.0 C (-31.0 F)
1989
-43.3 C (-45.9 F)
1990
-30.6 C (-23.1 F)
1991
-27.8 C (-18.0 F)
1992
-25.0 C (-13.0 F)
1993
-27.8 C (-18.0 F)
1994
-30.0 C (-22.0 F)
1995
-30.6 C (-23.1 F)
1996
-31.7 C (-25.1 F)
1997
-26.1 C (-15.0 F)
1998
-31.7 C (-25.1 F)
1999
-25.6 C (-14.1 F)
2000
-25.6 C (-14.1 F)
2001
-28.9 C (-20.0 F)
2002
-31.1 C (-24.0 F)
2003
-35.6 C (-32.1 F)
2004
-33.3 C (-27.9 F)
2005
-30.0 C (-22.0 F)
2006
-29.4 C (-20.9 F)
2007
-28.9 C (-20.0 F)
2008
-28.9 C (-20.0 F)
2009
n/a
2010
n/a
2011
n/a
2012
n/a
2013
n/a
2014
n/a
2015
n/a
2016
n/a
2017
n/a
2018
n/a
2019
n/a
2020
n/a
Wettest day (Rx1day)
The wettest day of the year at Green Mt Dam, 1939 to 2020. The record is 63.5 mm (2.5 in) in 2000, marked on the chart; the median year is 21.7 mm (0.9 in).
Wettest day (Rx1day) at Green Mt Dam by year
Year
Wettest day (Rx1day)
1939
21.1 mm (0.8 in)
1940
27.2 mm (1.1 in)
1941
30.7 mm (1.2 in)
1942
20.1 mm (0.8 in)
1943
33.0 mm (1.3 in)
1944
30.5 mm (1.2 in)
1945
24.1 mm (0.9 in)
1946
24.1 mm (0.9 in)
1947
29.2 mm (1.1 in)
1948
21.6 mm (0.9 in)
1949
16.8 mm (0.7 in)
1950
27.2 mm (1.1 in)
1951
30.0 mm (1.2 in)
1952
33.0 mm (1.3 in)
1953
17.3 mm (0.7 in)
1954
17.5 mm (0.7 in)
1955
16.8 mm (0.7 in)
1956
20.8 mm (0.8 in)
1957
29.2 mm (1.1 in)
1958
15.2 mm (0.6 in)
1959
38.1 mm (1.5 in)
1960
33.3 mm (1.3 in)
1961
23.9 mm (0.9 in)
1962
18.0 mm (0.7 in)
1963
35.6 mm (1.4 in)
1964
17.8 mm (0.7 in)
1965
19.6 mm (0.8 in)
1966
30.5 mm (1.2 in)
1967
16.3 mm (0.6 in)
1968
16.0 mm (0.6 in)
1969
28.4 mm (1.1 in)
1970
38.1 mm (1.5 in)
1971
15.2 mm (0.6 in)
1972
14.7 mm (0.6 in)
1973
19.6 mm (0.8 in)
1974
14.5 mm (0.6 in)
1975
30.5 mm (1.2 in)
1976
24.4 mm (1.0 in)
1977
16.5 mm (0.6 in)
1978
20.3 mm (0.8 in)
1979
28.7 mm (1.1 in)
1980
21.8 mm (0.9 in)
1981
21.8 mm (0.9 in)
1982
24.1 mm (0.9 in)
1983
26.7 mm (1.1 in)
1984
33.0 mm (1.3 in)
1985
39.4 mm (1.6 in)
1986
31.0 mm (1.2 in)
1987
15.2 mm (0.6 in)
1988
23.6 mm (0.9 in)
1989
24.4 mm (1.0 in)
1990
24.9 mm (1.0 in)
1991
16.0 mm (0.6 in)
1992
17.8 mm (0.7 in)
1993
20.8 mm (0.8 in)
1994
11.9 mm (0.5 in)
1995
38.6 mm (1.5 in)
1996
32.8 mm (1.3 in)
1997
34.5 mm (1.4 in)
1998
26.7 mm (1.1 in)
1999
21.3 mm (0.8 in)
2000
63.5 mm (2.5 in)
2001
28.7 mm (1.1 in)
2002
30.2 mm (1.2 in)
2003
26.7 mm (1.1 in)
2004
19.8 mm (0.8 in)
2005
29.2 mm (1.1 in)
2006
21.6 mm (0.9 in)
2007
19.8 mm (0.8 in)
2008
14.0 mm (0.6 in)
2009
16.0 mm (0.6 in)
2010
20.3 mm (0.8 in)
2011
24.9 mm (1.0 in)
2012
18.0 mm (0.7 in)
2013
18.3 mm (0.7 in)
2014
20.8 mm (0.8 in)
2015
17.5 mm (0.7 in)
2016
10.2 mm (0.4 in)
2017
14.5 mm (0.6 in)
2018
2.5 mm (0.10 in)
2019
18.8 mm (0.7 in)
2020
12.7 mm (0.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Green Mt Dam, 1939 to 2020. The record is 90.4 mm (3.6 in) in 2000, marked on the chart; the median year is 34.3 mm (1.4 in).
Wettest five days (Rx5day) at Green Mt Dam by year
Year
Wettest five days (Rx5day)
1939
21.1 mm (0.8 in)
1940
32.8 mm (1.3 in)
1941
40.9 mm (1.6 in)
1942
36.3 mm (1.4 in)
1943
60.7 mm (2.4 in)
1944
34.3 mm (1.4 in)
1945
45.7 mm (1.8 in)
1946
28.0 mm (1.1 in)
1947
33.0 mm (1.3 in)
1948
45.5 mm (1.8 in)
1949
27.2 mm (1.1 in)
1950
30.5 mm (1.2 in)
1951
49.8 mm (2.0 in)
1952
53.6 mm (2.1 in)
1953
31.1 mm (1.2 in)
1954
40.9 mm (1.6 in)
1955
41.4 mm (1.6 in)
1956
30.7 mm (1.2 in)
1957
44.0 mm (1.7 in)
1958
25.4 mm (1.0 in)
1959
65.7 mm (2.6 in)
1960
35.6 mm (1.4 in)
1961
84.7 mm (3.3 in)
1962
34.0 mm (1.3 in)
1963
49.3 mm (1.9 in)
1964
33.9 mm (1.3 in)
1965
44.7 mm (1.8 in)
1966
43.2 mm (1.7 in)
1967
29.7 mm (1.2 in)
1968
24.0 mm (0.9 in)
1969
55.9 mm (2.2 in)
1970
58.7 mm (2.3 in)
1971
23.2 mm (0.9 in)
1972
22.9 mm (0.9 in)
1973
44.0 mm (1.7 in)
1974
40.9 mm (1.6 in)
1975
33.0 mm (1.3 in)
1976
36.0 mm (1.4 in)
1977
30.7 mm (1.2 in)
1978
37.3 mm (1.5 in)
1979
58.4 mm (2.3 in)
1980
43.4 mm (1.7 in)
1981
26.4 mm (1.0 in)
1982
43.7 mm (1.7 in)
1983
48.3 mm (1.9 in)
1984
51.3 mm (2.0 in)
1985
62.4 mm (2.5 in)
1986
36.1 mm (1.4 in)
1987
29.1 mm (1.1 in)
1988
30.7 mm (1.2 in)
1989
39.6 mm (1.6 in)
1990
25.4 mm (1.0 in)
1991
35.9 mm (1.4 in)
1992
36.6 mm (1.4 in)
1993
24.4 mm (1.0 in)
1994
20.6 mm (0.8 in)
1995
43.5 mm (1.7 in)
1996
51.1 mm (2.0 in)
1997
38.8 mm (1.5 in)
1998
26.7 mm (1.1 in)
1999
34.0 mm (1.3 in)
2000
90.4 mm (3.6 in)
2001
28.7 mm (1.1 in)
2002
17.0 mm (0.7 in)
2003
34.8 mm (1.4 in)
2004
15.2 mm (0.6 in)
2005
21.5 mm (0.8 in)
2006
2.0 mm (0.08 in)
2007
20.8 mm (0.8 in)
2008
10.7 mm (0.4 in)
2009
12.2 mm (0.5 in)
2010
3.8 mm (0.15 in)
2011
n/a
2012
0.0 mm (0.00 in)
2013
0.0 mm (0.00 in)
2014
n/a
2015
n/a
2016
n/a
2017
n/a
2018
n/a
2019
n/a
2020
0.0 mm (0.00 in)
Longest dry spell (CDD)
The longest dry spell of the year at Green Mt Dam, 1939 to 2020. The record is 54 days in 1979, marked on the chart; the median year is 22 days.
Longest dry spell (CDD) at Green Mt Dam by year
Year
Longest dry spell (CDD)
1939
41 days
1940
36 days
1941
17 days
1942
23 days
1943
21 days
1944
40 days
1945
16 days
1946
19 days
1947
16 days
1948
33 days
1949
25 days
1950
29 days
1951
23 days
1952
46 days
1953
28 days
1954
18 days
1955
25 days
1956
24 days
1957
15 days
1958
25 days
1959
27 days
1960
20 days
1961
24 days
1962
26 days
1963
26 days
1964
17 days
1965
22 days
1966
23 days
1967
22 days
1968
21 days
1969
17 days
1970
28 days
1971
25 days
1972
21 days
1973
33 days
1974
22 days
1975
20 days
1976
26 days
1977
16 days
1978
27 days
1979
54 days
1980
44 days
1981
28 days
1982
16 days
1983
24 days
1984
17 days
1985
17 days
1986
23 days
1987
23 days
1988
28 days
1989
28 days
1990
37 days
1991
30 days
1992
29 days
1993
16 days
1994
23 days
1995
17 days
1996
40 days
1997
22 days
1998
24 days
1999
19 days
2000
38 days
2001
20 days
2002
30 days
2003
22 days
2004
12 days
2005
18 days
2006
4 days
2007
9 days
2008
4 days
2009
8 days
2010
10 days
2011
4 days
2012
12 days
2013
5 days
2014
4 days
2015
4 days
2016
3 days
2017
4 days
2018
3 days
2019
4 days
2020
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
61 years with a frost
Across 61 years with a frost, the median last spring frost at Green Mt Dam falls on 11 June and the median first autumn frost on 4 September, which leaves a median of 84 days between them.
In 1971 to 2006 the median growing season was 85 days. That is 7 days more than in 1940 to 1969.
Fitted over all years, the growing season changes by +1.9 days per decade at this station.
Frost dates and growing season at Green Mt Dam
Measure
Median, all years
Earliest period (1940 to 1969)
Recent period (1971 to 2006)
Recent against earliest
Fitted trend
Last spring frost
11 June
13 June
11 June
2 days earlier
-1.1 days per decade
First autumn frost
4 September
2 September
9 September
7 days later
+0.8 days per decade
Growing days
84 days
78 days
85 days
7 days more
+1.9 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
59 years, 1940 to 2001
A day with at least 23.4 mm (0.9 in) of rain is expected about once in 2 years. A day with at least 51.7 mm (2.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Green Mt Dam: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
23.4 mm (0.9 in)
5 years
31.0 mm (1.2 in)
10 years
36.0 mm (1.4 in)
25 years
42.3 mm (1.7 in)
50 years
47.0 mm (1.9 in)
100 years
51.7 mm (2.0 in)
Longer than the 59 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, 59 years of values from 1940 to 2001.
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: 63.5 mm (2.5 in) in 2000; 39.4 mm (1.6 in) in 1985; 38.1 mm (1.5 in) in 1959.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Green Mt Dam, at 1953. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1953 ran 0.5 C (1.0 F) higher than in the years before (possible change).
Suspected changes in the annual mean temperature at Green Mt Dam, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1953
+0.5
+1.0
possible
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 Green Mt Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Green Mt Dam 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.