Monthly Summary 



September, 1938 



Normal 



Extremes 



Barometer 



(Readings reduced to sea level) 



Maximum . 30.31, 15th 



Minimum 29.43, 20th 



Mean semi-daily 29.929 



Range 0.88 



Air Temperature 



Highest 85, 27th 



Lowest 35, 12th 



Mean 62.7 



Monthly range 50 



Highest mean daily 75.5, 27th 



Lowest mean daily 49, 16th 



Mean maximum 72.4 



Mean minimum 53.1 



Greatest daily range 36, 13th 



Least daily range 2, 16th 



Precipitation 



Precipitation. In inches 12.34 



Snow, in inches 



Maximum precipitation in 24 hrs. 6.32, 



15th and 16th 

 Number of days on which .01 or more 



inches of rain fell '. 16 



■Wind (miles) 



Total movement 3,236 



Greatest daily movement 243, 17th 



Least daily movement 42, 21st 



Mean hourly velocity 4.5 



Maximum velocity for 5 min. . . 28, 10th 



(corrected to conform to a cup anemometer) 

 Wind (direction) 



Prevailing direction w 



North, days 1 



Northeast, days 1 



East, days 1 



Southeast, days 7 



South, days 3 



Southwest, days 2 



West, days 4 



Northwest, days 11 



M' e a t h e r 



Mean relative humidity, per cent . . 75.8 



Mean cloudiness, per cent 56.8 



Number of clear days 6 



Number of fair days 14 



Number of cloudy days 10 



Number of hours bright sunshine 159.4 

 Percent of possible hours of bright 



sunshine 42.7 



Thunder and Lightning, 20th, 27th 

 Frosts, 12th 



30.45 



29.59 



30.068 



.86 



87.4 

 32.8 

 61.6 

 54.6 



3.79 



3,252 



4.5 

 22 



80.0 

 48.7 

 9 

 11 

 10 

 202.5 



54.4 



19 



30.65, 1924 

 29.32, 1900 



1.20, 1904; 0.57, 1910 



97.0, 1895, 1929 

 24.5, 1914 



8.74, 1907; 0.52, 1914 



15, 1918 ; 3, 1903 



4,686, 1896; 1,414, 1894 



39, 1915 



89, 1927; 68.0, 1932 



65, 1889; 27, 1908, 1914 



19, 1932; 2, 1907, 1928 



19, 1908; 3, 1889 



19, '89, '07; 4, '08, '16 



255, 1916; 110, 1907 



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 baaed on observations made from 18;9 to 

 1928. The third column gives extremes observed from 1889 to UI32. 



