YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
1956 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 15.93 | b | 12.33 | d | 14.13 | j |
1957 | 0.14 | i | 22.38 | l | 28.90 | b | 29.71 | b | 40.42 | 45.04 | c | 45.61 | c | 38.83 | b | 33.76 | i | 31.23 | 20.93 | c | 19.25 | c | 33.32 | c | ||
1958 | 21.50 | a | 29.00 | g | 24.07 | b | 28.75 | b | 36.57 | c | 42.07 | a | 49.64 | c | 51.68 | i | 39.83 | x | 26.55 | b | 15.12 | e | 20.79 | c | 29.45 | c |
1959 | 22.19 | 20.23 | b | 21.71 | 29.23 | 35.07 | d | 44.50 | 50.87 | 45.48 | b | 40.73 | 31.77 | 15.33 | 9.07 | c | 30.52 | |||||||||
1960 | 13.48 | 21.97 | 27.53 | a | 28.24 | a | 35.55 | b | 48.04 | d | 49.19 | 43.48 | 38.75 | b | 28.55 | 26.97 | 18.57 | a | 31.69 | |||||||
1961 | 16.03 | 26.92 | b | 26.42 | 28.23 | 32.96 | e | 48.59 | a | 50.48 | b | 52.91 | h | 38.62 | a | 31.21 | c | 19.00 | b | 15.87 | h | 31.85 | b | |||
1962 | 7.10 | a | 18.05 | g | 23.93 | c | 33.61 | g | 36.92 | f | 43.52 | a | 48.56 | f | 47.18 | c | 39.64 | b | ----- | z | 27.00 | d | 26.40 | k | 31.39 | f |
1963 | 7.80 | f | 29.67 | a | 28.29 | g | 27.70 | 40.39 | h | 41.14 | a | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 32.83 | i | |
1964 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
1965 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
1966 | ----- | z | ----- | z | ----- | z | ----- | z | 37.45 | i | 43.53 | k | 47.04 | g | 48.52 | d | 39.15 | d | ----- | z | 27.33 | f | 20.19 | d | 35.95 | i |
1967 | 18.46 | e | 22.00 | e | 24.81 | d | ----- | z | 38.52 | f | 44.19 | d | 51.70 | d | ----- | z | 45.19 | d | 28.81 | e | ----- | z | ----- | z | 33.60 | e |
1968 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 47.00 | f | 52.00 | a | 44.52 | 40.80 | 32.73 | a | 29.03 | 15.43 | a | 35.75 | f | |||
1969 | 18.61 | 18.11 | 22.65 | 29.47 | 39.57 | a | 46.60 | 51.71 | 44.94 | 40.62 | d | 26.58 | 19.83 | 20.84 | 31.63 | |||||||||||
1970 | 23.81 | 23.89 | a | 24.16 | 24.30 | ----- | z | 45.50 | 48.35 | 44.84 | 31.70 | 24.00 | ----- | z | 19.37 | a | 30.99 | b | ||||||||
1971 | 20.94 | 22.93 | 22.84 | 26.97 | 35.68 | 39.60 | 48.58 | 45.90 | 33.87 | 26.71 | 23.30 | 10.40 | a | 29.81 | ||||||||||||
1972 | 12.23 | a | 23.45 | 26.93 | a | 27.00 | 37.48 | 47.40 | 50.21 | c | 45.68 | l | 34.48 | i | 31.94 | 29.03 | ----- | z | 31.74 | c | ||||||
1973 | 9.35 | n | 23.71 | 26.32 | 29.83 | ----- | z | ----- | z | 52.83 | b | 46.26 | ----- | z | ----- | z | 27.41 | a | 26.50 | e | 33.27 | e | ||||
1974 | 17.65 | 20.96 | 29.58 | 27.63 | 34.29 | 46.70 | 49.00 | b | 46.18 | c | ----- | z | ----- | z | ----- | z | ----- | z | 34.00 | d | ||||||
1975 | ----- | z | ----- | z | ----- | z | 25.13 | o | 34.77 | a | 42.96 | f | 51.88 | f | 45.75 | c | ----- | z | 31.87 | a | ----- | z | 15.40 | k | 37.46 | i |
1976 | 14.79 | b | 25.19 | b | 22.97 | b | 27.84 | e | 38.67 | a | 41.73 | d | 51.26 | 45.96 | c | 43.60 | 29.13 | a | ----- | z | 7.68 | c | 31.71 | a | ||
1977 | 4.53 | a | 21.22 | a | 21.31 | b | 30.03 | a | 34.13 | 50.52 | a | 51.54 | c | 52.43 | a | 40.59 | a | 31.79 | c | 22.66 | a | 23.22 | d | 32.00 | ||
1978 | 25.38 | b | 26.93 | ----- | z | 33.04 | b | 37.06 | 43.52 | a | 51.17 | b | 47.58 | 39.30 | c | 31.72 | b | 19.76 | a | 11.03 | b | 33.32 | a | |||
1979 | 10.10 | 24.41 | a | 27.90 | b | 31.87 | g | 39.74 | 44.43 | b | 52.19 | e | ----- | z | 40.25 | f | 35.93 | a | 17.65 | d | 14.59 | b | 29.66 | c | ||
1980 | 20.10 | a | 26.56 | d | 24.36 | c | 32.59 | a | 38.97 | b | 38.44 | e | 50.52 | d | 47.13 | 42.17 | a | 31.14 | b | ----- | z | 19.00 | l | 35.20 | b | |
1981 | 20.69 | b | 24.08 | d | 25.34 | b | 31.90 | j | 37.07 | a | 46.52 | c | 49.72 | m | 50.90 | k | 43.38 | d | 29.30 | d | 28.04 | c | 24.19 | d | 30.96 | c |
1982 | 12.03 | a | 18.77 | b | 25.58 | 26.86 | i | 33.94 | 44.07 | c | 50.50 | c | ----- | z | 41.30 | c | 31.07 | b | 22.08 | f | 19.62 | r | 32.16 | d | ||
1983 | 23.04 | e | 27.46 | b | 30.76 | b | 28.17 | g | 37.32 | c | 43.31 | a | 47.65 | 52.60 | f | 42.48 | a | 33.21 | b | 27.24 | e | 21.31 | e | 33.38 | b | |
1984 | 5.13 | a | 16.93 | 27.59 | b | 30.96 | f | 39.83 | b | 42.27 | d | ----- | z | 51.50 | a | 39.71 | b | 30.00 | c | 27.22 | g | 12.76 | j | 31.62 | d | |
1985 | 12.48 | d | 13.65 | e | 21.44 | f | 32.14 | a | 38.23 | 49.68 | e | 55.26 | l | 46.36 | i | 37.17 | f | 30.59 | d | 13.96 | g | 4.75 | s | 29.46 | f | |
1986 | 23.25 | c | 30.16 | c | 29.83 | m | 29.88 | f | 36.40 | f | 50.14 | w | 50.09 | t | 52.38 | o | 38.07 | b | 31.82 | i | 21.26 | g | 11.09 | i | 30.49 | i |
1987 | 10.00 | d | 24.55 | f | 24.83 | h | 32.75 | b | 42.23 | e | 46.92 | d | 48.25 | g | 50.08 | g | 42.14 | a | 34.21 | b | 26.13 | 17.00 | a | 31.42 | d | |
1988 | 10.83 | a | 19.96 | c | 23.35 | e | 34.04 | e | 36.73 | e | 51.92 | f | 55.69 | e | 51.04 | f | 41.58 | d | 36.81 | 26.80 | j | 14.45 | b | 30.38 | c | |
1989 | 7.81 | 10.70 | a | 31.87 | 34.97 | 40.48 | f | 47.50 | d | 51.54 | e | 46.89 | c | 42.28 | a | 32.07 | a | 19.72 | a | 15.44 | d | 30.98 | a | |||
1990 | 19.90 | 16.43 | 26.31 | b | 38.59 | a | 38.58 | 44.82 | b | 54.67 | a | 52.46 | c | 46.81 | d | 31.10 | a | 20.57 | 4.22 | d | 32.87 | |||||
1991 | 14.03 | b | 24.50 | 27.32 | 31.43 | b | 36.45 | b | 38.43 | b | 52.69 | b | 51.19 | d | 44.50 | 34.07 | b | 27.25 | b | 16.14 | c | 33.17 | ||||
1992 | 19.37 | d | 26.52 | b | 27.42 | 36.86 | a | 46.14 | b | 49.33 | c | 51.40 | a | 52.27 | a | 43.24 | a | 36.06 | 25.04 | b | 16.16 | 35.82 | ||||
1993 | 6.48 | 15.00 | a | 33.14 | c | 32.73 | d | 42.38 | b | 43.28 | a | 46.61 | c | 49.25 | c | 41.17 | a | 35.29 | c | 14.93 | a | 18.30 | d | 31.55 | ||
1994 | 18.68 | c | 18.68 | c | 28.72 | b | 33.89 | b | 42.94 | 45.92 | d | 56.90 | b | 50.89 | c | 43.96 | e | 31.33 | g | 17.18 | b | 8.27 | e | 33.28 | a | |
1995 | 25.93 | c | 27.75 | d | 29.32 | i | ----- | z | 40.56 | d | 42.70 | c | 49.86 | b | 48.48 | h | 40.44 | c | 31.58 | e | 22.30 | g | 21.74 | d | 35.07 | d |
1996 | 20.00 | d | 21.43 | f | 27.08 | e | 32.35 | d | 37.36 | q | 44.85 | d | 53.10 | b | 49.69 | b | 38.72 | e | 31.58 | e | 26.78 | c | 24.54 | e | 34.87 | b |
1997 | 19.96 | f | 24.04 | d | 28.66 | b | 30.38 | d | ----- | z | 47.00 | b | 51.50 | a | 49.25 | c | 42.57 | g | 31.78 | h | 27.64 | e | 19.22 | d | 34.71 | d |
1998 | 25.81 | e | 25.44 | c | 27.31 | e | 30.11 | c | 39.30 | d | ----- | z | 57.19 | d | 52.08 | e | 47.75 | f | 33.31 | b | 28.28 | e | 15.45 | b | 33.43 | b |
1999 | 22.71 | g | 26.61 | e | 28.00 | f | 29.04 | f | 37.15 | d | 47.68 | e | 51.92 | e | 51.54 | g | 40.22 | c | 31.03 | b | 25.96 | e | 14.27 | e | 34.36 | d |
2000 | 20.45 | 27.17 | 27.86 | b | 33.93 | c | 36.82 | i | 42.40 | e | 50.93 | c | 51.91 | h | 41.28 | a | 32.03 | b | 19.83 | f | 16.92 | r | 34.51 | d | ||
2001 | 12.68 | c | 20.35 | e | 29.23 | a | 28.52 | e | 40.87 | a | 39.00 | j | 44.19 | d | 47.89 | c | 41.17 | a | 34.89 | d | 23.38 | d | 17.41 | d | 30.96 | a |
2002 | 18.41 | b | 22.79 | d | 20.57 | h | 29.30 | g | 33.77 | i | 46.25 | j | 55.92 | g | 46.27 | e | ----- | z | 25.22 | h | 20.36 | b | 22.79 | c | 26.12 | g |
2003 | 27.03 | a | 18.07 | 26.97 | 27.80 | j | 43.76 | j | 46.71 | b | 54.76 | b | 50.63 | a | 40.60 | e | 34.07 | b | 16.00 | b | 20.92 | f | 34.98 | c | ||
2004 | 10.96 | c | 14.35 | i | 29.59 | d | 32.29 | b | 35.28 | f | 47.71 | b | 53.61 | c | ----- | z | 39.19 | d | 32.97 | b | 22.67 | c | 18.32 | c | 31.92 | c |
2005 | 7.73 | a | 17.08 | b | 28.39 | c | 29.82 | b | 39.69 | e | 40.23 | d | 53.60 | a | 48.44 | f | 34.86 | b | ----- | z | 17.19 | d | 16.44 | d | 28.50 | b |
2006 | 23.15 | e | 18.00 | g | 22.83 | b | 28.08 | e | 35.79 | b | 44.58 | f | 52.97 | b | ----- | z | 42.54 | q | 29.68 | i | 21.83 | a | 11.31 | e | 27.99 | e |
2007 | 10.00 | a | ----- | z | 28.83 | a | 29.97 | a | 40.77 | 48.00 | a | 56.82 | c | 50.21 | b | 39.69 | a | 32.23 | a | 23.19 | d | 16.52 | h | 35.97 | b | |
2008 | 8.42 | e | 18.77 | g | 24.55 | b | 25.90 | a | 37.68 | c | 44.71 | b | 53.46 | c | 50.87 | a | ----- | z | 30.87 | 27.64 | e | 11.50 | a | 31.56 | b | |
2009 | 15.83 | g | 23.08 | c | 24.37 | a | 29.46 | b | 42.52 | b | 46.82 | b | 54.35 | ----- | z | 45.23 | 30.13 | 20.81 | c | 8.85 | d | 32.56 | b | |||
2010 | 21.72 | f | 23.92 | d | 24.31 | e | ----- | z | 34.03 | a | 46.69 | a | 53.23 | a | 48.07 | b | 39.46 | d | 36.28 | f | 22.72 | a | 24.33 | a | 35.20 | c |
2011 | 16.93 | a | 19.85 | b | 29.17 | a | 29.38 | a | 35.30 | a | ----- | z | ----- | z | 50.83 | a | 43.54 | b | 33.59 | b | 20.55 | a | ----- | z | 31.01 | c |
2012 | 15.62 | b | 20.52 | d | 28.94 | 33.17 | a | ----- | z | 44.63 | 53.71 | 52.63 | a | 43.14 | a | 32.60 | a | 27.79 | a | 20.50 | a | 33.93 | a | |||
2013 | 2.63 | a | 23.21 | 27.06 | 32.23 | 39.17 | a | 47.66 | a | 56.78 | d | 51.17 | a | 46.90 | 28.33 | a | 25.37 | 8.70 | a | 32.43 | ||||||
2014 | 17.39 | 26.79 | 28.03 | 31.93 | a | 38.58 | 47.97 | a | 57.77 | 52.42 | 47.23 | 35.61 | 25.80 | 26.27 | a | 36.32 | ||||||||||
2015 | 21.73 | a | 27.00 | 27.80 | a | 29.40 | 40.20 | a | 52.57 | 54.55 | 51.77 | 42.43 | 38.65 | 22.77 | 17.55 | 35.53 | ||||||||||
2016 | 15.00 | 22.76 | 29.90 | 34.67 | 40.26 | 49.23 | 52.35 | 51.27 | a | 40.63 | 33.90 | 25.50 | 12.35 | 33.99 | ||||||||||||
2017 | 10.32 | 25.68 | 29.97 | 31.80 | 39.06 | 48.57 | 53.90 | 55.19 | 42.67 | 26.87 | 27.60 | 11.55 | 33.60 | |||||||||||||
2018 | 21.84 | 14.11 | 23.68 | 31.67 | 42.19 | 47.37 | 56.58 | 51.52 | 40.27 | 29.87 | 18.13 | 16.42 | 32.80 | |||||||||||||
2019 | 16.42 | 18.14 | 27.26 | 33.04 | b | 38.06 | 45.80 | 52.29 | c | 49.54 | e | 41.21 | a | 21.00 | 19.18 | m | 22.09 | h | 34.28 | b | ||||||
2020 | 20.33 | m | 19.59 | 22.86 | b | 29.97 | 36.90 | 44.64 | e | 47.94 | m | 50.18 | n | 39.47 | m | 25.65 | n | 23.20 | t | 11.65 | n | 30.79 | g | |||
2021 | 16.19 | o | 15.62 | o | 19.88 | e | 26.38 | d | 31.19 | d | 51.61 | g | 57.86 | x | ----- | z | 41.48 | a | 33.11 | d | 25.24 | a | 14.38 | b | 27.38 | e |
2022 | 17.37 | a | 14.44 | a | 20.73 | a | 21.40 | 31.58 | 47.38 | v | 52.04 | e | ----- | z | 41.05 | k | 28.75 | k | 13.31 | d | 15.88 | o | 24.41 | e | ||
2023 | 19.25 | w | 16.25 | t | ----- | z | 24.45 | s | 39.94 | o | ----- | z | 53.19 | 54.13 | a | 42.87 | 34.13 | 23.23 | 21.52 | 38.18 | f | |||||
2024 | 23.35 | 25.86 | 27.74 | 30.92 | e | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 26.97 | h | |||
Period of Record Statistics | ||||||||||||||||||||||||||
MEAN | 16.22 | 22.22 | 26.42 | 30.50 | 37.99 | 45.44 | 52.10 | 48.93 | 41.20 | 31.53 | 22.75 | 16.60 | 32.91 | |||||||||||||
S.D. | 6.22 | 4.42 | 2.90 | 3.13 | 3.09 | 3.03 | 2.90 | 3.32 | 2.98 | 3.23 | 4.41 | 5.34 | 1.89 | |||||||||||||
SKEW | -0.28 | -0.49 | -0.18 | -0.13 | 0.03 | -0.33 | -0.30 | -0.58 | -0.63 | -0.72 | -0.39 | -0.16 | 0.35 | |||||||||||||
MAX | 27.03 | 30.16 | 33.14 | 38.59 | 46.14 | 52.57 | 57.77 | 55.19 | 47.23 | 38.65 | 29.03 | 26.50 | 36.32 | |||||||||||||
MIN | 2.63 | 10.70 | 19.88 | 21.40 | 31.19 | 38.43 | 44.19 | 38.83 | 31.70 | 21.00 | 13.31 | 4.22 | 29.81 | |||||||||||||
YRS | 53 | 52 | 54 | 49 | 48 | 51 | 52 | 42 | 49 | 51 | 49 | 47 | 15 |