MONTHLY SUMMARY 



SEPTEiMBER 1950 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.469, 27th 



Minimum . . ._ 29.454, 23rd 



Mean semi-daily 30.044 



Range 1.015 



Air Temperature, in Degrees F. 



Highest 84, 1st 



Lowest 29, 25th 



Mean 58.9 



Range 55 



Highest mean daily 72.5, 1st 



Lowest mean daily 42, 25th 



Mean maximum 69.4 



Mean minimum 48.8 



Greatest daily range 35, 8th, 18th 



Least daily range 5, 11th 



Degree-days of heating load for month. . 209 

 Degree-days cumulative for season 209 



Precipitation, in inches 



Precipitation 2.34 



Snow 



Maximum precip. In 24 hrs 93, 1st 



Number of days with .01 or more 10 



Wind, in miles 



Total movement 2530 



Greatest daily movement 249, 23rd 



Least dally movement 15, 8th 



Mean hourly velocity 3.5 



Maximum velocity 25, 23rd 



Wind, direction 



Prevailing direction WNW 



North, days 8 



Northeast, days 



East, days 



Southeast, days 1 



South, days 3 



Southwest, days 6 



West, days 4 



Northwest, days 8 



Weather 



Mean relative humidity, percent 80.5 



Mean cloudiness, percent 55 



Number of clear days 10 



Number of fair days 13 



Number of cloudy days 7 



Number of hours bright sunshine 2087 



Percent of possible hours of 



bright sunshine 56 



Thunder and lightning 



First Frost 25th 



Normal 



30.45 

 29.57 

 30.00 



87.7 

 33.2 

 61.7 



54.5 



4.24 

 10 



3271 



4.5 

 25.9 



WSW 



73.6 



49.9 



10 



10 



10 



201 



54.9 



Extr 



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 



70, 1934; 23, 1947 



19, 1932; 2, 1907, 1928 



19, 1908; 3, 1889 



20, 1934; 3, 1941, 1948 

 255, 1916; 106, 1934 



Sept. 21 Oct. 13, 1909; Aug. 22, 1894-95 



Note — 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 1938, 

 except that humidity lecords are based on observations made from 1929 to 1938. The 

 third column gives extremes observed from 1889 to 1949. 



