YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
1956 | ----- | z | ----- | z | ----- | z | 30.84 | k | 40.68 | 44.97 | 48.97 | 45.84 | 39.93 | 34.00 | 17.63 | 14.77 | 35.85 | d | ||||||||
1957 | -0.61 | 17.82 | 19.68 | 27.80 | 39.94 | 43.33 | 50.26 | 49.00 | 39.67 | 31.73 | a | 18.59 | a | 19.56 | d | 29.73 | ||||||||||
1958 | 17.13 | 25.11 | 21.13 | 29.73 | 41.48 | 46.07 | 46.42 | 49.81 | 40.63 | 32.90 | 20.90 | 19.94 | 32.60 | |||||||||||||
1959 | 15.77 | 10.00 | 21.39 | 28.17 | 33.16 | 46.13 | 48.45 | 46.23 | 42.00 | 32.27 | i | 18.67 | 18.35 | 29.85 | a | |||||||||||
1960 | 15.00 | 8.66 | ----- | z | ----- | z | ----- | z | 43.85 | q | 52.84 | 47.10 | 42.00 | 30.39 | h | 23.37 | 15.65 | 29.23 | e | |||||||
1961 | 15.52 | 27.83 | p | ----- | z | 28.65 | g | 37.94 | 47.23 | 50.58 | 53.16 | 37.20 | 31.29 | 21.70 | 13.81 | 34.27 | c | |||||||||
1962 | 3.42 | 16.21 | 19.71 | 31.57 | 39.00 | 44.53 | 47.84 | 46.84 | 40.03 | 35.80 | a | 26.87 | 20.48 | 31.03 | ||||||||||||
1963 | 0.81 | 22.79 | 23.60 | a | 29.67 | c | 40.03 | 45.73 | 50.13 | a | 50.25 | c | 47.44 | c | 37.31 | e | 25.46 | f | 13.42 | 32.83 | a | |||||
1964 | 12.11 | d | 10.96 | b | 13.84 | 28.60 | 38.39 | c | 44.13 | 50.77 | 45.29 | 38.00 | a | 33.61 | 22.97 | 16.35 | 29.59 | |||||||||
1965 | 18.77 | 15.89 | 9.45 | 32.27 | 35.29 | 44.03 | 48.81 | 47.52 | 32.80 | 32.40 | a | 26.00 | 17.55 | 30.06 | ||||||||||||
1966 | 15.34 | b | 13.26 | a | 21.52 | 26.87 | 37.71 | 42.33 | 52.42 | 47.84 | 43.90 | 30.26 | 23.21 | a | 14.10 | 30.73 | ||||||||||
1967 | 17.97 | 16.74 | a | 20.23 | a | 24.43 | 34.29 | 44.83 | 51.00 | 49.23 | 44.70 | 32.82 | c | 23.20 | 6.50 | a | 30.50 | |||||||||
1968 | 9.61 | 19.04 | b | 26.45 | 26.27 | 35.29 | 44.00 | 49.35 | 47.52 | 41.60 | 33.48 | 21.72 | e | 13.84 | 30.68 | |||||||||||
1969 | 13.97 | 18.68 | 17.87 | 33.58 | d | 38.94 | 41.87 | 50.00 | 52.00 | 43.50 | 27.41 | b | 23.11 | b | 17.03 | b | 31.50 | |||||||||
1970 | 15.81 | 21.25 | 19.23 | a | 25.07 | a | 38.32 | 45.87 | 52.58 | 51.26 | 37.97 | 28.71 | c | 23.00 | d | 15.66 | b | 31.23 | ||||||||
1971 | 14.10 | a | 18.65 | b | 20.25 | c | 29.23 | 36.40 | a | 45.07 | 47.68 | 53.48 | 37.29 | b | 30.58 | 23.00 | 13.19 | e | 30.74 | |||||||
1972 | 12.04 | c | 20.52 | f | 28.41 | d | 29.08 | e | 35.88 | e | 46.70 | g | 47.13 | 51.48 | 39.00 | b | 31.38 | e | 24.21 | b | 8.44 | d | 30.71 | b | ||
1973 | 11.35 | e | 16.44 | c | 23.67 | d | 27.81 | c | 35.78 | d | 47.43 | g | ----- | z | 51.58 | 40.57 | 34.87 | 24.83 | 18.87 | 28.58 | b | |||||
1974 | 13.52 | 19.36 | 21.79 | c | 31.87 | 35.10 | 46.63 | 53.42 | 46.97 | 37.60 | 31.94 | 24.67 | 14.16 | 31.42 | ||||||||||||
1975 | 12.16 | 16.30 | a | 19.90 | 22.57 | 34.65 | 41.87 | 53.19 | 46.58 | 36.67 | 31.68 | 18.14 | a | 17.00 | a | 29.22 | ||||||||||
1976 | 14.06 | 15.23 | c | 12.29 | j | 29.09 | h | 40.11 | l | 42.38 | f | 53.13 | a | 51.13 | a | 41.78 | c | 28.37 | a | 21.31 | a | 13.16 | 29.77 | d | ||
1977 | 2.35 | 17.00 | 18.06 | 28.63 | 37.00 | 48.87 | 51.67 | a | 48.61 | 41.83 | 35.41 | i | 22.97 | a | 15.40 | a | 30.22 | a | ||||||||
1978 | 12.55 | 13.56 | a | 24.33 | a | 33.40 | 38.10 | 44.37 | 51.39 | 48.23 | ----- | z | 34.79 | c | 14.44 | c | 4.65 | 29.07 | a | |||||||
1979 | -1.48 | b | 16.27 | b | 23.17 | a | 30.33 | 35.43 | a | 44.90 | a | 51.74 | 51.47 | a | 43.93 | a | 34.89 | l | 16.80 | e | 21.03 | a | 30.33 | a | ||
1980 | 7.71 | j | 20.59 | l | 17.35 | n | 30.16 | k | 40.00 | d | ----- | z | 51.23 | a | 47.39 | 42.04 | c | 32.83 | h | 22.04 | e | 20.23 | 37.15 | f | ||
1981 | 22.37 | a | 18.07 | 25.81 | 31.93 | a | 40.96 | c | 43.75 | f | 49.23 | 49.55 | 42.67 | 30.74 | 26.90 | 17.61 | 32.35 | a | ||||||||
1982 | 8.97 | a | 13.11 | 24.03 | a | 23.67 | 34.70 | d | 41.33 | 49.23 | a | 49.35 | 38.00 | 31.87 | 18.14 | b | 15.45 | b | 28.99 | |||||||
1983 | 20.37 | a | 25.92 | c | 28.62 | b | 26.90 | 34.68 | c | 45.62 | a | 51.07 | a | 55.53 | a | 40.97 | a | 36.13 | 26.27 | 10.09 | h | 35.64 | a | |||
1984 | 13.69 | b | 19.67 | b | 25.97 | b | 29.23 | 39.90 | b | ----- | z | 53.10 | 52.77 | 38.50 | ----- | z | ----- | z | ----- | z | 34.10 | d | ||||
1985 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
1986 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 16.23 | 16.23 | k | |
1987 | 13.61 | 21.46 | 26.17 | b | 35.00 | a | 43.55 | 48.53 | 52.45 | b | 48.77 | ----- | z | 32.52 | ----- | z | 19.07 | b | 34.11 | b | ||||||
1988 | 11.52 | 19.24 | 24.33 | a | 34.47 | 41.10 | 53.17 | 55.16 | 51.74 | 42.50 | b | 37.13 | 25.57 | 15.68 | 34.30 | |||||||||||
1989 | 15.54 | c | 6.00 | 27.22 | d | 32.90 | 39.42 | 47.30 | 56.42 | 51.42 | 42.41 | a | 36.48 | 26.83 | a | 13.69 | e | 32.97 | ||||||||
1990 | 19.55 | b | 16.81 | b | 26.00 | 34.63 | 38.42 | 47.47 | 52.80 | a | 53.41 | b | 47.45 | a | 35.19 | 28.10 | 6.28 | f | 36.35 | a | ||||||
1991 | ----- | z | ----- | z | 23.26 | 31.10 | 37.47 | a | 46.36 | b | 53.55 | b | 54.33 | a | 43.17 | 28.41 | b | 18.89 | b | 17.41 | b | 35.40 | b | |||
1992 | 17.03 | a | 24.17 | 29.97 | 34.63 | 42.42 | 47.83 | 49.16 | 49.87 | 42.78 | c | 35.48 | 21.52 | a | 10.90 | a | 33.81 | |||||||||
1993 | 11.74 | 11.22 | a | 26.77 | 32.53 | 41.56 | f | 44.62 | a | 46.62 | b | 47.94 | 41.45 | a | 33.61 | 15.83 | a | 18.89 | c | 30.11 | a | |||||
1994 | 21.67 | a | 14.18 | 27.00 | a | 32.24 | a | 43.40 | a | 46.56 | c | 49.23 | 50.89 | c | 44.73 | 34.23 | 18.83 | 20.77 | 33.64 | |||||||
1995 | 18.90 | 21.18 | 23.29 | 29.66 | a | 37.85 | e | 44.79 | a | 49.61 | m | 50.90 | a | 42.72 | a | 31.17 | a | 28.90 | a | 18.93 | c | 31.66 | a | |||
1996 | 11.35 | 16.69 | 18.65 | 32.53 | 36.30 | a | 44.96 | d | 53.00 | a | 51.97 | a | 41.21 | a | 33.79 | c | 24.32 | b | 18.22 | h | 33.16 | a | ||||
1997 | 12.64 | c | 16.12 | c | 25.67 | a | 27.96 | b | 39.40 | a | 49.25 | b | 52.58 | 51.53 | a | 45.86 | b | 34.48 | 24.52 | a | 15.03 | 32.92 | ||||
1998 | 18.26 | 22.04 | 25.48 | 32.57 | 40.16 | 42.57 | 54.23 | a | 54.58 | 48.67 | 34.90 | a | 30.17 | 15.61 | c | 34.94 | ||||||||||
1999 | 20.10 | 21.29 | 25.26 | 29.17 | 38.10 | 45.74 | c | 50.67 | a | 53.52 | 40.63 | 35.94 | 32.47 | 18.40 | a | 34.27 | ||||||||||
2000 | 17.37 | a | 23.62 | c | 26.97 | b | 34.21 | a | 40.75 | c | 45.00 | a | 54.52 | b | 53.07 | b | 42.23 | 35.52 | 15.77 | 14.73 | a | 33.65 | ||||
2001 | 14.38 | b | 14.64 | 25.52 | 32.82 | b | 39.31 | b | 48.24 | a | 55.39 | 54.19 | 46.79 | a | 33.17 | b | 29.59 | a | 15.24 | b | 34.11 | |||||
2002 | 17.17 | b | 16.59 | a | 15.13 | 28.28 | a | 36.64 | c | 44.65 | d | 55.83 | b | 47.53 | a | 44.67 | 27.13 | 23.53 | 24.18 | c | 31.78 | |||||
2003 | 22.87 | 14.78 | a | 26.53 | a | 33.43 | b | 39.84 | 45.60 | 57.00 | a | 55.90 | 41.59 | a | 35.94 | 18.43 | 21.66 | b | 34.46 | |||||||
2004 | 17.00 | 20.70 | b | 30.06 | 32.83 | 39.58 | 46.28 | a | 53.55 | 49.35 | 43.07 | b | 36.19 | 25.07 | 23.55 | 34.77 | ||||||||||
2005 | 16.71 | 17.82 | 26.13 | 32.30 | 39.10 | a | 45.85 | c | 52.39 | 49.82 | c | 45.13 | 37.97 | 25.76 | a | 13.13 | a | 33.51 | ||||||||
2006 | 22.43 | a | 16.64 | 23.81 | 35.33 | 40.29 | 49.07 | 57.26 | 51.58 | 43.46 | b | 33.65 | 26.40 | 18.39 | 34.86 | |||||||||||
2007 | 10.07 | b | 20.48 | a | 30.87 | 26.88 | v | 37.19 | o | 49.03 | 59.16 | 52.45 | 45.00 | 34.23 | 23.50 | 15.26 | 34.01 | b | ||||||||
2008 | 10.21 | c | 20.59 | 20.71 | 26.10 | 36.61 | 43.86 | a | 53.10 | 52.35 | 42.10 | 34.77 | 30.07 | 10.60 | a | 31.76 | ||||||||||
2009 | 16.87 | 23.30 | a | 24.06 | 30.53 | 38.39 | 44.79 | a | 50.26 | 50.81 | 44.73 | 28.06 | 25.70 | 10.97 | 32.37 | |||||||||||
2010 | 18.93 | a | 19.43 | 26.74 | 29.93 | a | 35.42 | 46.03 | a | 51.10 | 50.45 | 44.03 | 38.74 | 20.60 | 19.94 | 33.45 | ||||||||||
2011 | 17.71 | 11.32 | 28.23 | 30.40 | 36.97 | 45.20 | 54.29 | 53.48 | 44.63 | 37.74 | 22.33 | 15.61 | 33.16 | |||||||||||||
2012 | 20.16 | 17.41 | 29.71 | 34.37 | 38.14 | b | 46.87 | 56.65 | 53.00 | a | 45.00 | 33.48 | 28.80 | e | 19.81 | 35.28 | ||||||||||
2013 | 14.77 | 18.82 | 23.81 | 27.87 | 40.07 | a | 46.63 | 54.90 | 54.29 | 47.90 | 31.32 | 28.82 | h | 12.96 | d | 33.94 | a | |||||||||
2014 | 12.23 | r | 10.30 | h | 24.04 | f | 31.79 | f | 39.50 | c | 45.23 | d | 54.61 | 50.44 | d | 45.17 | 36.61 | 21.07 | a | 20.76 | b | 39.17 | d | |||
2015 | 20.70 | a | 24.41 | a | 29.87 | 31.89 | c | 40.07 | a | 49.50 | 54.91 | i | 52.20 | a | 46.70 | 46.19 | d | 18.20 | 16.68 | c | 34.22 | a | ||||
2016 | 17.75 | c | 24.65 | c | 26.04 | c | 35.90 | i | 36.13 | 45.86 | a | 50.68 | 50.55 | 49.07 | 38.45 | 26.43 | 7.74 | 33.94 | a | |||||||
2017 | 8.39 | 23.21 | 34.55 | 36.60 | 40.48 | 50.48 | a | 55.03 | 50.90 | 42.23 | 34.10 | 21.67 | 15.37 | a | 34.42 | |||||||||||
2018 | 21.87 | 11.54 | 25.29 | 28.27 | 41.19 | 44.50 | 51.84 | 49.42 | 41.40 | 35.94 | 21.03 | a | 19.48 | h | 33.84 | a | ||||||||||
2019 | 21.70 | a | 5.79 | 19.34 | b | 37.17 | 46.63 | a | 54.61 | l | 54.00 | y | 52.40 | a | 47.46 | f | 26.57 | a | 27.42 | f | ----- | z | 29.94 | e | ||
2020 | ----- | z | ----- | z | ----- | z | ----- | z | 30.60 | a | 43.59 | h | 50.79 | l | 51.73 | p | 41.38 | q | 37.60 | u | ----- | z | 14.38 | r | 30.60 | k |
2021 | 7.83 | y | -2.65 | k | 2.14 | x | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
Period of Record Statistics | ||||||||||||||||||||||||||
MEAN | 14.58 | 17.54 | 23.94 | 30.56 | 38.34 | 45.84 | 52.02 | 50.61 | 42.38 | 33.63 | 23.06 | 16.02 | 32.42 | |||||||||||||
S.D. | 5.63 | 4.65 | 4.49 | 3.29 | 2.77 | 2.25 | 2.82 | 2.54 | 3.23 | 3.43 | 3.99 | 3.96 | 1.86 | |||||||||||||
SKEW | -1.03 | -0.45 | -0.62 | -0.26 | 0.04 | 0.62 | 0.17 | -0.11 | -0.28 | 0.46 | 0.02 | -0.56 | -0.23 | |||||||||||||
MAX | 22.87 | 25.92 | 34.55 | 37.17 | 46.63 | 53.17 | 59.16 | 55.90 | 49.07 | 46.19 | 32.47 | 24.18 | 35.28 | |||||||||||||
MIN | -1.48 | 5.79 | 9.45 | 22.57 | 30.60 | 41.33 | 46.42 | 45.29 | 32.80 | 26.57 | 14.44 | 4.65 | 28.99 | |||||||||||||
YRS | 58 | 56 | 56 | 54 | 59 | 54 | 58 | 62 | 59 | 56 | 57 | 57 | 34 |