MONTHLY SUMMARY 



SEPTEMBER 1951 



Normal 



Extremes 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.407 



Minimum 29.722 



Mean semi-daily 30.095 



Range 0.685 



Air Temperature, in Degrees F. 



Highest 85, 12th 



Lowest 28, 30th 



Mean 61.4 



Range 57 



Highest mean daily 75.5, 14th 



Lowest mean daily 38.5, 30th 



Mean maximum 72.1 



Mean minimum 50.8 



Greatest daily range 36, 9th, 10th 



Least daily range 2, 15th 



Degree-days of heating load for month, 147 

 Degree-days cumulative for season 147 



Precipitation, in inches 



Precipitation 2.63 



Snow 



Maximum precip. in 24 hrs 1.03, 15th 



Number of days with .01 or more 7 



Wind, in miles 



Total movement 2769 



Greatest daily movement 229, 28th 



Least daily movement 20, 5th 



Mean hourly velocity 3.9 



Maximum velocity 25, 28th, 29th 



Wind, direction 



Prevailing direction WSW 



North, days 3 



Northeast, days 1 



East, days 



Southeast, days 5 



South, days 7 



Southwest, days 1 



West, days 6 



Northwest, days 7 



Weather 



Mean relative humidity, percent 81.3 



Mean cloudiness, percent 29.1 



Number of clear days 13 



Number of fair days 10 



Number of cloudy days _. 7 



Number of hours bright sunshine ....203.9 

 Percent of possible hours of 



bright sunshine 54.5 



Thunder and lightning 



First frost 30th 



30.45 

 29.57 

 30.00 



87.7 

 33.2 

 61.7 



54.5 



4.24 

 10 



3271 



4.5 

 25.9 



WSW 



30.65, 1924 

 28.41, 1938 



1.99, 1938; .57, 1910 



97, 1895, 1929 

 24.5, 1914 



14.55, 1938; .52, 1914 



16, 1933; 3, 1903 



4,686, 1896; 1,414, 1894 



80, 1938 



73.6 

 49.9 



10 



10 



10 

 201 



54.9 



Sept. 21 



70, 1934; 23, 1947 



19, 1932; 2, 1907, 1928 



19, 1908; 3, 1889 



20, 1934; 3, 1941, 1948 

 255, 1916; 106, 1934 



Oct. 13, 1909; Aug. 22, 1894-95 



Note— The first column in the above summary gives observations made durmg the 

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

 1889 to 1938, except that humidity records are based on observations made from 

 1929 to 1938. The third column gives extremes observed from 1889 to 1950. 



