Monthly Summary 



September. 1988 



Normal 



Extremes 



Barometer 



(Readings reduced to sea level) [ 



Maximum 30.40, 10th { 30.45 



Minimum 28.41, 21st 29.59 



Mean semi-daily 30.037 I 30.068 



Range 1.99 .86 



Air Temperature 



Highest 87 1st 87.4 



Lowest 36, 10th 32.8 



Mean 59.4 61.6 



Range 51 54.6 



Highest mean daily 72.5, 1st 



Lowest mean daily 49.5, 30th 



Mean maximum 70.5 



Mean minimum 48.3 



Greatest daily range . . 35, 10th, 11th, 26th 

 Least daily range 5, 18th 



Precipitation 



Precipitation. In inches 14.55 3.79 



Snow, in inches 



Maximum precipitation in 24 hrs. 



5.17, 20th and 21st 

 Number of days on which .01 or more 



inches of precipitation fell 12 



Wind (miles) 



Total movement 3971 



Greatest daily movement 283,22nd 



Least daily movement 52, 10th 



Mean hourly velocity 5.5 



Maximum velocity, 5 min., 80, 21st 



Wind (direction) 



Prevailing direction sw 



North, days 8 



Northeast, days 



East, days 



Southeast, days 4 



South, days 11 



Southwest, days 1 



West, days 



Northwest, days 6 



Weather 



Mean relative humidity, per cent 72.7 73.7 



Mean cloudiness, per cent 58 48.7 



Number of clear days 10 9 



Number of fair days 7 11 



Number of cloudy days 13 10 



Number of hours bright sunshine 165 -02.5 



Percent of possible hours of bright 



sunshine 44.2 54.4 



Thunder and lightning 14th, 15th, 19th,20th 



Frost 10th 19th 



First frost 10th 



3,252 



4.5 

 22 



30.65, 1924 

 29.32, 1900 



1.20,1904; 0.57,1910 



97.0, 1895, 1929 

 24.5, 1914 



12.34, 1933; 0.52, 1914 



15, 1918; 3, 1903 

 4,686, 1896; 1,414, 1894 



39, 1915, 1934 



70.0, 3 934; 27, 1908, 1914 



19, 1932; 2, 1907, 1928 



19, 1908; 3, 1889 



20, 1934; 4, '08, '16 



255,1916; 106,1934 



Aug. 22, '94, '95; Oct. 13, '09 



NoTK— The first column in the above summary gives observations made during the 

 month. The second column gives the averages based on observations made from 1889 

 to 1928. except that humidity records are based on observations made from 1929 to 1937. 

 The third column gives extremes observed from 1889 to 1987 



