| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1968 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 30.63 | 20.61 | 25.62 | |||
| 1969 | 20.84 | 22.79 | 24.60 | a | 31.10 | 41.23 | 46.59 | a | 50.29 | 47.13 | a | 43.53 | 32.26 | 29.53 | 26.00 | 34.66 | ||||||||||
| 1970 | 26.55 | 28.82 | 26.68 | 26.13 | 38.42 | 47.13 | 51.19 | 48.87 | 39.53 | 34.52 | 31.87 | 19.52 | 34.94 | |||||||||||||
| 1971 | 21.77 | 24.26 | a | 23.13 | 28.63 | 37.16 | 41.63 | 50.60 | a | 52.00 | 40.03 | 31.58 | 27.43 | 16.58 | 32.90 | |||||||||||
| 1972 | 16.65 | 25.76 | 30.84 | 27.90 | 38.13 | 43.23 | 49.84 | 49.93 | a | 40.37 | 34.97 | 28.07 | 15.71 | 33.45 | ||||||||||||
| 1973 | 20.90 | 28.32 | 24.39 | 30.10 | 39.90 | 44.73 | 49.87 | 47.61 | 41.60 | 34.42 | 28.77 | 28.19 | 34.90 | |||||||||||||
| 1974 | 19.77 | 23.32 | 27.81 | 30.03 | 34.58 | 46.83 | 48.83 | a | 48.58 | 45.27 | 34.45 | 29.47 | 22.87 | 34.32 | ||||||||||||
| 1975 | 18.90 | a | 21.61 | 25.48 | 24.20 | 34.55 | 41.73 | 49.58 | 45.87 | 44.23 | 34.71 | 27.17 | 25.39 | 32.79 | ||||||||||||
| 1976 | 22.68 | 24.03 | 21.33 | a | 27.97 | 36.77 | 40.43 | 48.81 | 44.52 | 43.30 | 34.03 | 31.43 | 22.03 | 33.11 | ||||||||||||
| 1977 | 14.00 | 26.89 | 23.23 | 31.93 | 33.17 | b | 47.77 | 49.52 | 53.60 | a | 43.20 | 36.59 | b | 28.33 | 26.55 | 34.56 | ||||||||||
| 1978 | 29.29 | 28.21 | 33.23 | a | 30.07 | 34.33 | a | 43.47 | 48.48 | 47.30 | a | 39.27 | 35.52 | 25.43 | 17.19 | 34.32 | ||||||||||
| 1979 | 19.87 | 25.54 | 29.61 | 30.73 | 39.13 | 43.17 | 51.10 | 47.29 | 45.53 | 40.32 | 25.93 | a | 26.93 | a | 35.43 | |||||||||||
| 1980 | 24.13 | 31.55 | 24.50 | a | 32.73 | 35.58 | 39.17 | 49.06 | 43.27 | a | 41.30 | 36.87 | 29.43 | 26.45 | 34.50 | |||||||||||
| 1981 | 28.06 | 25.54 | 28.10 | a | 32.36 | b | 36.16 | 40.86 | a | 45.35 | 48.10 | 43.33 | 33.81 | 33.57 | p | 28.94 | 35.51 | |||||||||
| 1982 | 16.39 | 23.71 | 25.37 | a | 25.87 | 34.90 | 44.43 | 47.55 | 48.52 | 38.83 | 33.58 | 24.77 | 20.67 | a | 32.05 | |||||||||||
| 1983 | 27.16 | 29.71 | 30.87 | 29.23 | 38.42 | 40.67 | 44.87 | 49.17 | a | 41.33 | 36.74 | 28.23 | 24.19 | 35.05 | ||||||||||||
| 1984 | 24.10 | 25.00 | 29.06 | 29.30 | 38.58 | 40.10 | 50.06 | 47.80 | a | 40.67 | 31.29 | 26.53 | 16.39 | 33.24 | ||||||||||||
| 1985 | 17.58 | 20.96 | 24.20 | a | 33.83 | 35.77 | 46.10 | 52.45 | 45.39 | 39.23 | 31.87 | 20.17 | 22.42 | 32.50 | ||||||||||||
| 1986 | 32.87 | 29.75 | 32.10 | 29.97 | 37.47 | a | 48.00 | 45.74 | 51.16 | 38.67 | 34.87 | 27.63 | 25.35 | 36.13 | ||||||||||||
| 1987 | 18.65 | 26.79 | 27.32 | 34.00 | 38.19 | 47.00 | 44.61 | 46.94 | 41.69 | a | 38.74 | 30.30 | 21.00 | 34.60 | ||||||||||||
| 1988 | 19.77 | 23.48 | 25.13 | 33.87 | 33.61 | 43.93 | 50.39 | 48.00 | 40.87 | 40.06 | 28.87 | 19.71 | 33.97 | |||||||||||||
| 1989 | 14.48 | 14.82 | 29.97 | 36.13 | 35.13 | 44.90 | 45.00 | 44.16 | 41.17 | 33.42 | 25.27 | 23.29 | 32.31 | |||||||||||||
| 1990 | 23.65 | 18.25 | 27.74 | 35.87 | 36.29 | 42.60 | 51.39 | 49.65 | 44.47 | 34.13 | 24.67 | 13.74 | 33.54 | |||||||||||||
| 1991 | 21.19 | 31.61 | 25.29 | 29.07 | 33.03 | 40.00 | 50.65 | 49.39 | 44.33 | 36.00 | 29.53 | 24.10 | 34.52 | |||||||||||||
| 1992 | 25.16 | 30.07 | 30.65 | 35.17 | 41.29 | 45.93 | 47.77 | 49.23 | 41.67 | 35.77 | 26.37 | 16.19 | 35.44 | |||||||||||||
| 1993 | 15.61 | 19.46 | 30.10 | 31.07 | 40.61 | 41.13 | 41.16 | 44.71 | 39.57 | 36.06 | 19.50 | 20.97 | 31.66 | |||||||||||||
| 1994 | 25.52 | 22.36 | 28.39 | 32.83 | 39.61 | 42.70 | 52.29 | 45.81 | 43.70 | 30.06 | 19.90 | a | 19.00 | a | 33.51 | |||||||||||
| 1995 | 29.71 | 29.71 | 28.39 | 25.18 | s | 35.38 | o | 37.00 | v | 43.17 | y | 37.60 | z | 41.33 | z | 29.56 | v | 26.00 | w | 26.57 | x | 29.27 | ||||
| 1996 | 22.50 | u | 30.25 | y | 22.00 | z | 29.50 | v | ----- | z | 34.25 | z | 38.00 | z | 47.00 | z | 34.00 | y | 30.00 | w | 30.00 | w | 24.56 | v | 9999.00 | |
| 1997 | 21.20 | u | 18.88 | t | 22.20 | z | 29.38 | v | 38.36 | t | 39.71 | w | 46.22 | v | ----- | z | 34.67 | z | 34.36 | q | 30.50 | r | 22.92 | r | 9999.00 | |
| 1998 | 23.77 | r | 24.27 | q | 28.62 | o | 28.18 | m | 33.33 | p | 38.76 | m | 49.31 | o | 47.42 | s | 44.18 | m | 30.29 | n | 25.08 | r | 19.70 | u | 9999.00 | |
| 1999 | 22.67 | v | 15.71 | u | 22.86 | x | 22.82 | s | 30.00 | v | 36.11 | u | 41.91 | t | 45.00 | w | 37.91 | s | 31.11 | v | 27.00 | r | 21.47 | p | 9999.00 | |
| 2000 | 23.44 | m | 26.31 | p | 23.94 | o | 31.73 | s | 32.60 | p | 44.00 | l | 46.33 | p | 48.87 | p | 39.75 | n | 30.91 | t | 23.71 | p | 23.50 | u | 9999.00 | |
| 2001 | 22.50 | u | 20.07 | m | 27.95 | k | 32.67 | u | 35.20 | u | 41.20 | t | 45.33 | s | 47.54 | r | 40.82 | s | 34.89 | m | 30.29 | p | 22.23 | r | 9999.00 | |
| 2002 | 17.00 | n | 25.38 | l | 25.65 | k | 28.94 | m | 32.44 | m | 44.15 | q | 50.06 | n | 44.50 | m | 38.45 | s | 25.70 | k | 26.08 | q | 23.38 | o | 9999.00 | |
| 2003 | 27.19 | o | 20.12 | l | 25.65 | n | 26.88 | m | ----- | z | 40.31 | n | 55.86 | q | 46.92 | s | 42.33 | l | 33.64 | t | 24.00 | r | 26.00 | s | 9999.00 | |
| 2004 | 21.09 | t | 23.82 | r | 28.73 | p | 28.69 | q | 36.18 | n | 41.35 | m | 50.79 | q | 46.81 | o | 37.85 | q | 32.10 | u | 21.23 | q | 21.89 | l | 9999.00 | |
| 2005 | 20.67 | m | 21.92 | p | 28.25 | k | 27.08 | r | 35.80 | p | 39.94 | n | 50.55 | t | 47.06 | o | 34.71 | p | 31.56 | o | 24.47 | o | 20.25 | o | 9999.00 | |
| 2006 | 22.88 | n | 18.57 | n | 21.89 | m | 27.62 | q | 32.38 | w | 40.22 | u | 48.36 | t | 41.88 | o | 40.25 | r | 28.64 | t | 27.12 | v | 26.57 | x | 9999.00 | |
| 2007 | 10.50 | w | 12.00 | x | 22.40 | z | 25.50 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 22.05 | 25.27 | 27.31 | 30.77 | 37.00 | 43.62 | 48.71 | 47.85 | 41.80 | 34.87 | 27.12 | 21.85 | 33.94 | |||||||||||||
| S.D. | 4.92 | 4.16 | 3.04 | 3.06 | 2.47 | 2.70 | 2.75 | 2.44 | 2.08 | 2.49 | 3.31 | 4.17 | 1.16 | |||||||||||||
| SKEW | 0.29 | -0.49 | 0.02 | -0.12 | 0.10 | 0.07 | -0.98 | 0.22 | 0.19 | 0.37 | -0.98 | -0.15 | -0.21 | |||||||||||||
| MAX | 32.87 | 31.61 | 33.23 | 36.13 | 41.29 | 48.00 | 52.45 | 53.60 | 45.53 | 40.32 | 31.87 | 28.94 | 36.13 | |||||||||||||
| MIN | 14.00 | 14.82 | 21.33 | 24.20 | 33.03 | 39.17 | 41.16 | 43.27 | 38.67 | 30.06 | 19.50 | 13.74 | 31.66 | |||||||||||||
| NO YRS | 27 | 27 | 27 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 27 | 25 | |||||||||||||