Record envelope, standing records and threshold days for Orman Dam (USC00396357), South Dakota, United States, with 69 years of record.
Key Facts for Orman Dam
Orman Dam (USC00396357) is a weather station in South Dakota, United States at 44.73 latitude and -103.67 longitude, 894 m (2,933 ft) above sea level.
The station reports from 1906 to 1974, 69 years of record.
1,464 records set at Orman Dam still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Orman Dam set a daily record high maximum temperature of 37.2 C (99.0 F) on 21 June 1974.
About the Station
Location: South Dakota, United States, 44.73 latitude, -103.67 longitude.
Elevation: 894 m (2,933 ft).
Period of record: 1906 to 1974, 69 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 Orman 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 Orman Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
20.0 C (68.0 F)
-38.3 C (-36.9 F)
n/a
n/a
Feb
22.8 C (73.0 F)
-38.9 C (-38.0 F)
n/a
n/a
Mar
30.6 C (87.1 F)
-34.4 C (-29.9 F)
n/a
n/a
Apr
32.8 C (91.0 F)
-18.9 C (-2.0 F)
n/a
n/a
May
37.8 C (100.0 F)
-11.1 C (12.0 F)
n/a
n/a
Jun
41.7 C (107.1 F)
-2.2 C (28.0 F)
n/a
n/a
Jul
43.3 C (109.9 F)
2.8 C (37.0 F)
n/a
n/a
Aug
43.3 C (109.9 F)
0.0 C (32.0 F)
n/a
n/a
Sep
40.0 C (104.0 F)
-6.7 C (19.9 F)
n/a
n/a
Oct
35.0 C (95.0 F)
-21.7 C (-7.1 F)
n/a
n/a
Nov
27.2 C (81.0 F)
-31.1 C (-24.0 F)
n/a
n/a
Dec
22.8 C (73.0 F)
-35.6 C (-32.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Orman Dam still stand. 1936 holds the most, with 59.
Standing records at Orman Dam by the year they were set
Year set
Standing records
1906
17
1907
15
1908
18
1909
21
1910
27
1911
30
1912
10
1913
23
1914
19
1915
18
1916
50
1917
22
1918
40
1919
47
1920
27
1921
35
1922
18
1923
14
1924
20
1925
30
1926
25
1927
19
1928
12
1929
21
1930
17
1931
33
1932
27
1933
19
1934
22
1935
23
1936
59
1937
20
1938
15
1939
27
1940
18
1941
27
1942
14
1943
18
1944
13
1945
18
1946
17
1947
16
1948
23
1949
19
1950
31
1951
25
1952
21
1953
18
1954
24
1955
13
1956
16
1957
10
1958
21
1959
24
1960
25
1961
11
1962
22
1963
28
1964
17
1965
20
1966
10
1967
12
1968
15
1969
20
1970
7
1971
8
1972
18
1973
11
1974
14
All-Time Record Progression
4 new records
4 all-time records were set at Orman Dam between 14 February 1936 and 18 April 1970. Each dot is a new record.
When Orman Dam set new all-time records
Date
Kind
Detail
1936-02-14
Record low minimum temperature
Record low minimum temperature -38.9 C (-38.0 F)
1936-07-06
Record high maximum temperature
Record high maximum temperature 43.3 C (109.9 F)
1944-01-27
Record daily snowfall
Record daily snowfall 35.6 cm (14.0 in)
1970-04-18
Record daily snowfall
Record daily snowfall 61.0 cm (24.0 in)
Wettest Day of Each Month
May: 88.9 mm (3.5 in)
The wettest day on record for each calendar month at Orman Dam. The most was 88.9 mm (3.5 in) on 25 May 1907.
Record daily precipitation for each month at Orman Dam
Month
Record daily precipitation (mm)
Date
Jan
27.9 mm (1.1 in)
27 January 1944
Feb
15.7 mm (0.6 in)
3 February 1924
Mar
21.3 mm (0.8 in)
21 March 1946
Apr
72.4 mm (2.9 in)
20 April 1933
May
88.9 mm (3.5 in)
25 May 1907
Jun
62.2 mm (2.4 in)
8 June 1964
Jul
53.1 mm (2.1 in)
15 July 1915
Aug
81.3 mm (3.2 in)
23 August 1973
Sep
56.9 mm (2.2 in)
28 September 1923
Oct
54.6 mm (2.1 in)
8 October 1924
Nov
38.1 mm (1.5 in)
11 November 1911
Dec
17.8 mm (0.7 in)
10 December 1909
Period of Record Coverage
1906 to 1974
Complete yearUnder 90 percent of days
69 years of record at Orman Dam, 1906 to 1974. 7 years have data for under 90 percent of days and are left out of rankings: 1906, 1907, 1908, 1910, 1928, 1955, 1974.
Cooler than the station meanWarmer than the station mean
One stripe for each of 53 complete years at Orman Dam, 1911 to 1973. Blue stripes are years cooler than the station's own mean of 8.3 C (46.9 F); red stripes are warmer. The coolest year was 1916, at 5.6 C (42.1 F), and the warmest was 1921, at 10.0 C (49.9 F). The strongest colour marks a difference of 2.7 C (4.9 F).
Annual mean temperature at Orman Dam as warming stripes, 1911 to 1973
Year
Annual mean temperature
Difference from the station mean
1911
8.4 C
+0.16 C
1913
7.8 C
-0.48 C
1914
9.0 C
+0.72 C
1915
7.2 C
-1.02 C
1916
5.6 C
-2.62 C
1917
6.7 C
-1.56 C
1918
8.4 C
+0.18 C
1919
8.2 C
-0.06 C
1921
10.0 C
+1.70 C
1922
7.2 C
-1.06 C
1924
6.8 C
-1.46 C
1925
8.7 C
+0.48 C
1926
8.5 C
+0.20 C
1929
6.5 C
-1.75 C
1930
8.1 C
-0.17 C
1931
9.7 C
+1.47 C
1932
7.3 C
-1.00 C
1933
8.9 C
+0.60 C
1934
9.6 C
+1.34 C
1935
8.1 C
-0.16 C
1936
7.8 C
-0.47 C
1937
7.6 C
-0.67 C
1938
9.6 C
+1.35 C
1939
9.9 C
+1.64 C
1940
8.7 C
+0.41 C
1941
9.6 C
+1.33 C
1942
9.1 C
+0.82 C
1943
9.0 C
+0.78 C
1944
7.8 C
-0.42 C
1945
7.8 C
-0.50 C
1946
9.1 C
+0.86 C
1947
8.3 C
+0.06 C
1948
8.2 C
-0.04 C
1950
6.2 C
-2.03 C
1951
6.6 C
-1.70 C
1952
8.6 C
+0.35 C
1953
9.5 C
+1.24 C
1954
9.1 C
+0.89 C
1956
8.7 C
+0.49 C
1957
8.0 C
-0.21 C
1958
8.8 C
+0.54 C
1959
7.7 C
-0.59 C
1960
7.5 C
-0.77 C
1962
8.6 C
+0.34 C
1963
9.5 C
+1.20 C
1964
8.4 C
+0.11 C
1965
8.0 C
-0.25 C
1967
8.6 C
+0.33 C
1968
7.9 C
-0.35 C
1969
8.2 C
-0.02 C
1970
8.0 C
-0.23 C
1972
7.6 C
-0.65 C
1973
8.9 C
+0.66 C
The fitted trend in annual mean temperature here over 1911 to 1973 is 0.1 C (-0.1 to 0.2) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.4) per decade. The slope is a straight line fitted to 53 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Orman Dam
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (-0.1 to 0.2) per decade
0.1 F (-0.1 to 0.4) per decade
1911 to 1973
53
Not clearly different from zero
Mean daily maximum
0.14 C (-0.03 to 0.31) per decade
0.2 F (-0.1 to 0.6) per decade
1911 to 1973
53
Not clearly different from zero
Mean daily minimum
0.01 C (-0.15 to 0.18) per decade
0.03 F (-0.26 to 0.32) per decade
1911 to 1973
53
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
1906 to 1974
Yearly extremes at Orman Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
43.3 C (109.9 F)
1936
39.4 C (102.9 F)
69
Coldest night (TNn)
-38.9 C (-38.0 F)
1936
-31.1 C (-24.0 F)
69
Wettest day (Rx1day)
88.9 mm (3.5 in)
1907
37.3 mm (1.5 in)
69
Wettest five days (Rx5day)
146.6 mm (5.8 in)
1907
54.9 mm (2.2 in)
69
Longest dry spell (CDD)
88 days
1952
36 days
69
Hottest day (TXx)
The hottest day of the year at Orman Dam, 1906 to 1974. The record is 43.3 C (109.9 F) in 1936, marked on the chart; the median year is 39.4 C (102.9 F).
Hottest day (TXx) at Orman Dam by year
Year
Hottest day (TXx)
1906
41.7 C (107.1 F)
1907
37.8 C (100.0 F)
1908
40.0 C (104.0 F)
1909
39.4 C (102.9 F)
1910
40.6 C (105.1 F)
1911
38.9 C (102.0 F)
1912
37.8 C (100.0 F)
1913
38.3 C (100.9 F)
1914
40.0 C (104.0 F)
1915
38.9 C (102.0 F)
1916
39.4 C (102.9 F)
1917
41.1 C (106.0 F)
1918
39.4 C (102.9 F)
1919
41.7 C (107.1 F)
1920
36.7 C (98.1 F)
1921
40.6 C (105.1 F)
1922
35.6 C (96.1 F)
1923
37.2 C (99.0 F)
1924
38.3 C (100.9 F)
1925
38.9 C (102.0 F)
1926
41.1 C (106.0 F)
1927
36.1 C (97.0 F)
1928
39.4 C (102.9 F)
1929
39.4 C (102.9 F)
1930
40.6 C (105.1 F)
1931
42.8 C (109.0 F)
1932
37.8 C (100.0 F)
1933
41.7 C (107.1 F)
1934
41.7 C (107.1 F)
1935
41.1 C (106.0 F)
1936
43.3 C (109.9 F)
1937
42.2 C (108.0 F)
1938
41.1 C (106.0 F)
1939
41.1 C (106.0 F)
1940
42.2 C (108.0 F)
1941
41.7 C (107.1 F)
1942
38.9 C (102.0 F)
1943
38.9 C (102.0 F)
1944
37.2 C (99.0 F)
1945
38.9 C (102.0 F)
1946
38.9 C (102.0 F)
1947
39.4 C (102.9 F)
1948
38.9 C (102.0 F)
1949
40.6 C (105.1 F)
1950
36.1 C (97.0 F)
1951
41.1 C (106.0 F)
1952
40.6 C (105.1 F)
1953
38.3 C (100.9 F)
1954
40.6 C (105.1 F)
1955
40.0 C (104.0 F)
1956
37.8 C (100.0 F)
1957
39.4 C (102.9 F)
1958
40.6 C (105.1 F)
1959
38.9 C (102.0 F)
1960
40.6 C (105.1 F)
1961
39.4 C (102.9 F)
1962
37.2 C (99.0 F)
1963
37.2 C (99.0 F)
1964
38.3 C (100.9 F)
1965
39.4 C (102.9 F)
1966
40.0 C (104.0 F)
1967
38.3 C (100.9 F)
1968
38.3 C (100.9 F)
1969
43.3 C (109.9 F)
1970
41.1 C (106.0 F)
1971
39.4 C (102.9 F)
1972
37.8 C (100.0 F)
1973
42.2 C (108.0 F)
1974
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at Orman Dam, 1906 to 1974. The record is -38.9 C (-38.0 F) in 1936, marked on the chart; the median year is -31.1 C (-24.0 F).
Coldest night (TNn) at Orman Dam by year
Year
Coldest night (TNn)
1906
-21.7 C (-7.1 F)
1907
-33.3 C (-27.9 F)
1908
-31.7 C (-25.1 F)
1909
-30.0 C (-22.0 F)
1910
-30.0 C (-22.0 F)
1911
-34.4 C (-29.9 F)
1912
-34.4 C (-29.9 F)
1913
-35.0 C (-31.0 F)
1914
-30.0 C (-22.0 F)
1915
-32.8 C (-27.0 F)
1916
-38.3 C (-36.9 F)
1917
-35.0 C (-31.0 F)
1918
-35.0 C (-31.0 F)
1919
-32.2 C (-26.0 F)
1920
-31.1 C (-24.0 F)
1921
-24.4 C (-11.9 F)
1922
-33.3 C (-27.9 F)
1923
-28.9 C (-20.0 F)
1924
-36.1 C (-33.0 F)
1925
-34.4 C (-29.9 F)
1926
-30.0 C (-22.0 F)
1927
-37.8 C (-36.0 F)
1928
-34.4 C (-29.9 F)
1929
-32.8 C (-27.0 F)
1930
-33.3 C (-27.9 F)
1931
-23.3 C (-9.9 F)
1932
-32.2 C (-26.0 F)
1933
-32.8 C (-27.0 F)
1934
-33.3 C (-27.9 F)
1935
-32.2 C (-26.0 F)
1936
-38.9 C (-38.0 F)
1937
-30.0 C (-22.0 F)
1938
-28.3 C (-18.9 F)
1939
-31.7 C (-25.1 F)
1940
-30.0 C (-22.0 F)
1941
-22.8 C (-9.0 F)
1942
-30.0 C (-22.0 F)
1943
-33.9 C (-29.0 F)
1944
-33.9 C (-29.0 F)
1945
-30.0 C (-22.0 F)
1946
-31.1 C (-24.0 F)
1947
-28.9 C (-20.0 F)
1948
-29.4 C (-20.9 F)
1949
-36.1 C (-33.0 F)
1950
-35.6 C (-32.1 F)
1951
-31.1 C (-24.0 F)
1952
-31.7 C (-25.1 F)
1953
-26.1 C (-15.0 F)
1954
-30.0 C (-22.0 F)
1955
-27.2 C (-17.0 F)
1956
-27.2 C (-17.0 F)
1957
-29.4 C (-20.9 F)
1958
-27.2 C (-17.0 F)
1959
-31.1 C (-24.0 F)
1960
-34.4 C (-29.9 F)
1961
-27.8 C (-18.0 F)
1962
-30.0 C (-22.0 F)
1963
-35.0 C (-31.0 F)
1964
-30.6 C (-23.1 F)
1965
-29.4 C (-20.9 F)
1966
-32.2 C (-26.0 F)
1967
-31.7 C (-25.1 F)
1968
-32.2 C (-26.0 F)
1969
-31.1 C (-24.0 F)
1970
-28.3 C (-18.9 F)
1971
-28.3 C (-18.9 F)
1972
-36.1 C (-33.0 F)
1973
-28.9 C (-20.0 F)
1974
-31.1 C (-24.0 F)
Wettest day (Rx1day)
The wettest day of the year at Orman Dam, 1906 to 1974. The record is 88.9 mm (3.5 in) in 1907, marked on the chart; the median year is 37.3 mm (1.5 in).
Wettest day (Rx1day) at Orman Dam by year
Year
Wettest day (Rx1day)
1906
40.9 mm (1.6 in)
1907
88.9 mm (3.5 in)
1908
53.3 mm (2.1 in)
1909
33.5 mm (1.3 in)
1910
32.3 mm (1.3 in)
1911
38.1 mm (1.5 in)
1912
45.0 mm (1.8 in)
1913
47.5 mm (1.9 in)
1914
24.9 mm (1.0 in)
1915
53.1 mm (2.1 in)
1916
22.9 mm (0.9 in)
1917
27.7 mm (1.1 in)
1918
28.7 mm (1.1 in)
1919
27.9 mm (1.1 in)
1920
50.8 mm (2.0 in)
1921
25.4 mm (1.0 in)
1922
40.4 mm (1.6 in)
1923
56.9 mm (2.2 in)
1924
54.6 mm (2.1 in)
1925
52.8 mm (2.1 in)
1926
25.4 mm (1.0 in)
1927
40.6 mm (1.6 in)
1928
41.9 mm (1.6 in)
1929
40.6 mm (1.6 in)
1930
35.6 mm (1.4 in)
1931
28.4 mm (1.1 in)
1932
47.0 mm (1.9 in)
1933
72.4 mm (2.9 in)
1934
24.9 mm (1.0 in)
1935
25.4 mm (1.0 in)
1936
28.4 mm (1.1 in)
1937
51.8 mm (2.0 in)
1938
22.1 mm (0.9 in)
1939
26.7 mm (1.1 in)
1940
32.5 mm (1.3 in)
1941
55.4 mm (2.2 in)
1942
35.6 mm (1.4 in)
1943
48.8 mm (1.9 in)
1944
44.7 mm (1.8 in)
1945
33.0 mm (1.3 in)
1946
48.3 mm (1.9 in)
1947
57.2 mm (2.3 in)
1948
39.9 mm (1.6 in)
1949
24.6 mm (1.0 in)
1950
21.3 mm (0.8 in)
1951
24.1 mm (0.9 in)
1952
46.7 mm (1.8 in)
1953
34.0 mm (1.3 in)
1954
43.4 mm (1.7 in)
1955
33.0 mm (1.3 in)
1956
32.8 mm (1.3 in)
1957
25.4 mm (1.0 in)
1958
19.1 mm (0.8 in)
1959
34.0 mm (1.3 in)
1960
41.9 mm (1.6 in)
1961
34.0 mm (1.3 in)
1962
47.2 mm (1.9 in)
1963
24.9 mm (1.0 in)
1964
62.2 mm (2.4 in)
1965
39.9 mm (1.6 in)
1966
32.8 mm (1.3 in)
1967
36.1 mm (1.4 in)
1968
37.3 mm (1.5 in)
1969
27.9 mm (1.1 in)
1970
36.3 mm (1.4 in)
1971
49.5 mm (1.9 in)
1972
46.2 mm (1.8 in)
1973
81.3 mm (3.2 in)
1974
41.9 mm (1.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Orman Dam, 1906 to 1974. The record is 146.6 mm (5.8 in) in 1907, marked on the chart; the median year is 54.9 mm (2.2 in).
Wettest five days (Rx5day) at Orman Dam by year
Year
Wettest five days (Rx5day)
1906
27.1 mm (1.1 in)
1907
146.6 mm (5.8 in)
1908
53.3 mm (2.1 in)
1909
83.1 mm (3.3 in)
1910
49.6 mm (2.0 in)
1911
57.2 mm (2.3 in)
1912
64.9 mm (2.6 in)
1913
54.9 mm (2.2 in)
1914
37.1 mm (1.5 in)
1915
92.7 mm (3.6 in)
1916
57.4 mm (2.3 in)
1917
39.7 mm (1.6 in)
1918
51.5 mm (2.0 in)
1919
49.5 mm (1.9 in)
1920
107.9 mm (4.2 in)
1921
42.2 mm (1.7 in)
1922
67.8 mm (2.7 in)
1923
75.2 mm (3.0 in)
1924
66.8 mm (2.6 in)
1925
52.8 mm (2.1 in)
1926
47.8 mm (1.9 in)
1927
90.4 mm (3.6 in)
1928
57.1 mm (2.2 in)
1929
61.7 mm (2.4 in)
1930
36.1 mm (1.4 in)
1931
28.4 mm (1.1 in)
1932
82.8 mm (3.3 in)
1933
86.1 mm (3.4 in)
1934
40.6 mm (1.6 in)
1935
49.6 mm (2.0 in)
1936
33.5 mm (1.3 in)
1937
132.1 mm (5.2 in)
1938
29.2 mm (1.1 in)
1939
44.3 mm (1.7 in)
1940
62.2 mm (2.4 in)
1941
135.3 mm (5.3 in)
1942
83.3 mm (3.3 in)
1943
59.8 mm (2.4 in)
1944
70.4 mm (2.8 in)
1945
48.5 mm (1.9 in)
1946
63.3 mm (2.5 in)
1947
92.2 mm (3.6 in)
1948
79.6 mm (3.1 in)
1949
29.5 mm (1.2 in)
1950
30.1 mm (1.2 in)
1951
47.0 mm (1.9 in)
1952
75.9 mm (3.0 in)
1953
52.8 mm (2.1 in)
1954
78.4 mm (3.1 in)
1955
44.5 mm (1.8 in)
1956
41.4 mm (1.6 in)
1957
37.1 mm (1.5 in)
1958
39.9 mm (1.6 in)
1959
47.0 mm (1.9 in)
1960
44.7 mm (1.8 in)
1961
41.1 mm (1.6 in)
1962
80.2 mm (3.2 in)
1963
53.4 mm (2.1 in)
1964
99.1 mm (3.9 in)
1965
65.8 mm (2.6 in)
1966
38.4 mm (1.5 in)
1967
48.3 mm (1.9 in)
1968
80.5 mm (3.2 in)
1969
52.3 mm (2.1 in)
1970
57.7 mm (2.3 in)
1971
72.1 mm (2.8 in)
1972
67.2 mm (2.6 in)
1973
94.0 mm (3.7 in)
1974
54.4 mm (2.1 in)
Longest dry spell (CDD)
The longest dry spell of the year at Orman Dam, 1906 to 1974. The record is 88 days in 1952, marked on the chart; the median year is 36 days.
Longest dry spell (CDD) at Orman Dam by year
Year
Longest dry spell (CDD)
1906
31 days
1907
68 days
1908
34 days
1909
36 days
1910
35 days
1911
84 days
1912
36 days
1913
35 days
1914
44 days
1915
33 days
1916
30 days
1917
42 days
1918
43 days
1919
32 days
1920
23 days
1921
37 days
1922
71 days
1923
28 days
1924
22 days
1925
49 days
1926
27 days
1927
33 days
1928
44 days
1929
27 days
1930
41 days
1931
45 days
1932
47 days
1933
31 days
1934
56 days
1935
49 days
1936
52 days
1937
43 days
1938
62 days
1939
43 days
1940
36 days
1941
60 days
1942
37 days
1943
46 days
1944
30 days
1945
54 days
1946
37 days
1947
40 days
1948
31 days
1949
22 days
1950
42 days
1951
36 days
1952
88 days
1953
33 days
1954
29 days
1955
32 days
1956
39 days
1957
46 days
1958
29 days
1959
39 days
1960
46 days
1961
51 days
1962
28 days
1963
27 days
1964
23 days
1965
42 days
1966
24 days
1967
35 days
1968
48 days
1969
38 days
1970
30 days
1971
24 days
1972
31 days
1973
23 days
1974
33 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
53 years with a frost
Across 53 years with a frost, the median last spring frost at Orman Dam falls on 13 May and the median first autumn frost on 25 September, which leaves a median of 133 days between them.
Fitted over all years, the growing season changes by -0.6 days per decade at this station.
Frost dates and growing season at Orman Dam
Measure
Median, all years
Earliest period
Recent period (1939 to 1973)
Recent against earliest
Fitted trend
Last spring frost
13 May
n/a
12 May
n/a
-0.6 days per decade
First autumn frost
25 September
n/a
22 September
n/a
-1.2 days per decade
Growing days
133 days
n/a
132 days
n/a
-0.6 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
58 years, 1909 to 1973
A day with at least 36.9 mm (1.5 in) of rain is expected about once in 2 years. A day with at least 79.2 mm (3.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Orman 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
36.9 mm (1.5 in)
5 years
48.7 mm (1.9 in)
10 years
56.3 mm (2.2 in)
25 years
65.7 mm (2.6 in)
50 years
72.5 mm (2.9 in)
100 years
79.2 mm (3.1 in)
Longer than the 58 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, 58 years of values from 1909 to 1973.
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: 81.3 mm (3.2 in) in 1973; 72.4 mm (2.9 in) in 1933; 62.2 mm (2.4 in) in 1964.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Orman Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Orman 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.