SWAN FALLS POWER HOUSE, IDAHO

Monthly Average Minimum Temperature (Degrees Fahrenheit)

(108928)

File last updated on Apr 4, 2013
*** Note *** Provisional Data *** After Year/Month 201303
a = 1 day missing, b = 2 days missing, c = 3 days, ..etc..,
z = 26 or more days missing, A = Accumulations present
Long-term means based on columns; thus, the monthly row may not
sum (or average) to the long-term annual value.
MAXIMUM ALLOWABLE NUMBER OF MISSING DAYS : 5
Individual Months not used for annual or monthly statistics if more than 5 days are missing.
Individual Years not used for annual statistics if any month in that year has more than 5 days missing.
YEAR(S) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
1935 ----- z ----- z ----- z ----- z ----- z ----- z 63.55 60.17 a 53.83 40.68 26.93 22.23 44.56
1936 27.97 29.62 h 29.87 a 41.43 50.90 a 58.63 66.07 c 63.62 b 49.18 b 41.80 a 25.03 a 26.58 43.74
1937 6.97 a 23.85 a 35.43 a 37.87 49.16 55.00 67.23 60.29 53.73 41.29 37.47 31.57 a 41.65
1938 28.79 c 33.72 c 33.13 a 40.73 47.00 d 56.76 a 65.07 b 60.67 a 56.45 a 43.87 a 27.10 26.97 43.35
1939 28.03 25.29 34.26 42.03 49.77 53.10 64.77 63.39 51.87 43.10 29.47 30.87 43.00
1940 27.97 33.45 36.61 41.70 50.97 61.17 66.30 a 63.81 54.97 44.97 29.73 27.84 44.96
1941 26.97 32.96 35.60 a 40.93 49.74 54.80 65.45 61.48 49.70 41.06 32.89 b 30.61 43.52
1942 16.77 25.61 30.20 a 41.07 44.52 51.80 65.23 60.61 51.53 42.35 32.27 29.94 40.99
1943 24.84 28.07 30.06 44.03 45.63 a 51.50 60.47 a 59.77 52.67 42.81 30.40 24.61 41.24
1944 17.00 28.14 28.77 38.00 47.90 51.66 a 60.90 57.81 49.63 43.61 32.57 23.77 a 39.98
1945 27.37 a 31.07 a 29.94 37.73 46.94 51.52 a 63.27 a 60.30 a 46.67 42.32 33.33 25.29 41.31
1946 24.52 26.50 35.42 40.57 b 47.71 c 55.57 64.55 60.06 47.57 37.39 30.53 30.35 41.73
1947 17.20 a 29.43 35.06 41.10 52.32 53.00 64.39 58.68 48.50 43.20 a 31.73 26.42 41.75
1948 ----- z ----- z ----- z ----- z ----- z ----- z ----- z 58.71 50.43 40.68 30.83 20.34 b 40.20
1949 5.16 23.68 34.96 c 42.37 52.76 b 57.03 63.81 62.94 54.43 37.74 35.10 27.35 41.44
1950 22.00 28.43 33.61 39.67 45.06 54.03 64.65 60.94 54.43 46.06 36.00 32.52 43.12
1951 25.32 30.56 a 29.61 40.07 48.65 54.40 64.71 61.26 51.00 41.77 32.47 25.26 42.09
1952 21.26 24.86 30.55 42.17 49.19 55.30 63.13 63.23 53.13 43.55 27.37 29.87 41.97
1953 36.65 31.61 34.84 38.57 45.06 52.17 64.87 62.16 53.97 43.84 38.38 a 27.35 44.12
1954 31.65 32.14 31.71 41.63 50.16 52.80 64.13 a 58.32 50.80 41.13 35.14 a 24.84 42.87
1955 21.19 23.64 30.35 37.79 b 46.28 b 56.62 a 61.42 64.48 d 53.61 b 43.48 b 30.30 30.84 41.67
1956 29.00 21.66 34.25 g 42.10 50.93 b 55.00 64.06 59.84 51.43 41.84 28.97 25.96 c 42.80
1957 17.97 28.82 36.10 a 41.17 a 50.48 57.57 62.68 59.74 52.63 42.00 30.67 30.77 42.55
1958 27.35 35.75 33.52 40.47 53.61 58.50 63.58 65.16 51.93 43.32 32.93 31.65 44.81
1959 31.00 31.36 33.26 41.60 45.13 59.07 64.77 61.10 51.93 43.42 28.30 23.55 42.87
1960 20.42 28.76 35.23 40.63 45.97 57.77 68.29 58.03 55.27 40.90 35.00 23.84 42.51
1961 24.26 34.46 36.35 40.13 49.32 61.73 66.16 66.19 48.53 41.13 29.73 26.32 43.69
1962 15.81 27.11 31.42 42.53 47.90 54.97 61.23 59.39 52.57 43.03 34.73 30.26 41.74
1963 18.29 35.68 35.29 38.67 51.23 54.50 60.74 62.00 57.50 47.71 36.17 25.16 43.58
1964 24.16 24.10 31.06 37.93 a 46.90 54.47 63.03 58.52 49.77 42.58 32.67 30.16 41.28
1965 30.06 30.50 29.81 43.73 46.58 55.80 61.84 59.74 47.57 42.71 37.33 25.42 42.59
1966 29.03 28.43 33.94 40.13 50.16 55.00 62.52 61.65 56.00 39.45 37.03 28.35 43.47
1967 32.13 31.36 34.84 37.67 47.61 56.23 67.45 64.94 57.14 a 41.90 35.43 24.42 44.26
1968 24.32 33.72 37.10 38.53 48.16 57.30 64.16 58.71 51.97 42.32 35.30 29.00 43.38
1969 28.06 29.82 31.26 40.80 51.97 56.90 63.35 60.94 52.73 38.58 31.13 29.32 42.91
1970 31.55 31.36 34.10 36.13 47.16 57.07 63.56 d 62.10 46.03 38.42 36.43 28.45 42.70
1971 29.35 30.79 32.84 39.37 49.71 54.53 62.84 65.16 46.93 40.06 33.37 26.45 42.62
1972 25.16 29.24 36.26 38.70 47.90 56.70 61.06 61.06 46.57 42.16 33.73 18.71 41.44
1973 25.00 30.57 34.97 40.41 a 50.16 56.30 64.26 61.74 50.97 42.42 36.63 32.00 43.79
1974 23.97 30.04 a 34.77 39.90 47.39 60.07 a 62.84 60.32 51.37 42.19 36.03 29.06 43.16
1975 23.94 31.32 34.55 37.33 46.84 54.33 66.71 59.06 52.07 44.19 33.47 29.42 42.77
1976 27.61 28.90 30.26 40.00 50.10 54.13 63.87 58.00 54.07 40.77 31.60 21.39 41.72
1977 17.97 27.00 33.35 44.50 46.35 61.53 62.58 63.26 51.60 41.19 32.07 30.70 a 42.68
1978 32.52 33.71 39.23 42.27 d 47.23 55.87 63.42 60.35 52.23 42.13 29.73 22.06 43.40
1979 13.58 28.96 36.58 40.07 50.52 56.87 65.03 62.13 54.60 45.55 28.40 29.74 42.67
1980 25.13 31.97 35.61 44.37 49.29 53.10 63.90 58.84 51.63 40.58 31.53 26.61 42.71
1981 28.94 28.36 34.97 40.97 47.10 53.30 61.00 62.77 52.83 39.19 37.07 30.16 43.05
1982 21.06 24.71 33.65 35.73 46.26 56.87 60.26 60.77 ----- z 42.03 29.83 27.65 39.89
1983 28.84 34.25 38.00 37.37 46.74 54.07 59.68 63.42 50.97 41.90 36.40 22.74 42.86
1984 20.74 25.97 34.87 39.00 44.77 50.10 63.52 62.52 47.00 37.23 33.13 17.29 c 39.68
1985 15.16 20.82 29.52 43.23 48.71 56.70 68.26 58.13 47.73 39.26 24.07 10.39 38.50
1986 25.87 35.71 40.26 40.13 48.55 60.47 60.45 64.42 49.57 40.23 34.57 23.06 43.61
1987 21.35 29.50 36.13 ----- z 52.68 58.67 59.48 58.52 49.63 40.65 32.40 23.97 42.09
1988 19.77 27.41 34.68 42.20 47.26 58.33 61.87 53.16 47.37 48.03 36.33 23.23 41.64
1989 21.03 18.89 36.45 43.83 47.06 57.93 64.35 58.55 51.13 41.61 30.20 23.39 41.20
1990 28.39 26.71 35.68 45.43 46.81 55.60 63.06 60.45 55.50 39.71 30.93 10.87 41.60
1991 17.74 33.86 36.39 40.63 47.61 54.00 63.39 63.71 51.77 39.55 29.53 23.26 41.79
1992 25.23 31.21 36.03 42.57 50.03 a 56.17 55.81 61.81 52.67 44.48 31.50 22.90 42.53
1993 20.23 24.93 36.03 41.30 52.23 52.47 54.90 56.74 50.70 42.81 22.27 26.32 40.08
1994 28.65 26.89 37.03 42.57 52.19 56.83 66.13 63.06 53.57 41.94 28.60 25.06 43.54
1995 29.71 32.93 35.94 40.43 49.29 52.73 62.68 56.10 53.07 38.48 j 37.17 27.68 43.43
1996 26.77 27.21 34.87 39.23 46.77 54.53 61.84 58.10 48.43 42.03 33.07 29.10 41.83
1997 27.77 28.64 ----- z 40.70 51.19 57.77 62.48 62.39 55.63 41.58 33.73 24.06 44.18
1998 32.19 31.93 36.10 41.53 49.19 ----- z ----- z 64.06 57.50 42.32 36.27 24.29 41.54
1999 28.42 29.75 33.32 38.30 45.45 56.50 61.47 a 62.48 50.77 40.79 b 37.07 26.32 42.55
2000 27.68 33.93 35.87 44.70 50.45 57.43 63.45 b 63.27 a 50.07 c ----- z 42.43 27.69 b 45.18
2001 24.10 28.68 38.16 39.50 52.40 a 57.46 d 64.00 c 65.45 54.59 c 41.86 b 36.27 27.94 44.20
2002 28.39 26.50 32.84 42.67 49.23 59.17 67.61 59.96 d 52.73 38.63 a 30.87 30.74 43.28
2003 32.03 29.50 38.32 42.30 50.42 59.57 68.55 64.19 52.30 45.29 29.67 31.87 45.33
2004 26.19 30.31 38.68 44.07 49.61 58.23 65.87 62.87 51.07 43.13 32.23 29.77 44.34
2005 27.32 29.00 37.19 42.00 51.00 54.80 64.10 63.36 c 49.70 41.55 30.33 23.87 42.85
2006 32.55 27.39 35.84 43.53 50.29 60.77 68.42 59.23 49.63 40.68 34.63 25.23 44.02
2007 21.71 31.68 ----- z 41.37 52.06 58.00 70.81 62.52 50.73 40.39 31.97 26.97 44.38
2008 24.97 30.31 32.71 36.17 49.68 56.33 65.32 62.84 50.07 40.87 35.10 24.84 42.43
2009 25.52 28.93 33.06 40.37 50.52 58.23 64.84 61.03 56.40 40.71 31.87 20.26 42.64
2010 31.03 34.18 35.10 38.33 44.42 55.43 62.32 60.96 g 51.96 g 45.65 32.00 29.42 40.79
2011 25.67 a 27.60 c 35.96 c 38.32 b 45.83 a 54.66 a 62.07 a 62.60 a 55.03 a 44.03 31.17 a 21.67 a 42.05
2012 27.21 c 30.27 c 36.77 a 44.63 c 47.50 a 54.47 67.03 64.00 c 52.10 40.00 a 34.07 27.93 a 43.83
2013 12.42 28.79 32.41 b ----- z ----- z ----- z ----- z ----- z ----- z ----- z ----- z ----- z 24.54
Period of Record Statistics
MEAN 24.67 29.28 34.39 40.69 48.71 56.00 63.72 61.21 51.76 41.91 32.57 26.21 42.57
S.D. 5.85 3.52 2.59 2.20 2.28 2.55 2.65 2.44 2.76 2.12 3.49 4.21 1.26
SKEW -0.96 -0.43 -0.35 -0.06 0.05 0.12 -0.37 -0.41 0.00 0.34 -0.24 -1.32 -0.51
MAX 36.65 35.75 40.26 45.43 53.61 61.73 70.81 66.19 57.50 48.03 42.43 32.52 45.33
MIN 5.16 18.89 28.77 35.73 44.42 50.10 54.90 53.16 46.03 37.23 22.27 10.39 38.50
NO YRS 77 76 74 75 76 75 76 77 76 76 78 78 66