Monthly Summary 



December 19.17 



Normal 



Extremes 



Barometer 



( Readings reduced to sea level) 



Maximum 30.58, 27th 



Minimum 29.16, 7th 



Mean semi-daily 30.098 



Range 1.42 



Air Temperature 



Highest 48, 22nd 



Lowest 6, 31st 



Mean 27.6 



Monthly range 42 



tiighest mean daily 35.5, 18th, 19th, 26th 



Lowest mean daily 15.5, 31st 



Mean maximum 34.8 



Mean minimum 20.5 



Greatest daily range 24, 22nd 



Least daily range 5, 18th 



Frecipitalioit 



Precipitation. In inches 2.44 



Snow, in inches 5.00 



Maximum precipitation in 24 hrs. 



.81, 6th, 7th 

 Number of days on which .01 or more 



inches of precipitation fell ... 9 



Wind (miles) 



Total movement 



Greatest daily movement 250, 



Least daily movement ... . 46,5th, 



Mean hourly velocity 



Maximum velocity, 5 min., 39, 



Wind (direction) 



Prevailing direction 



North, days ; . 



Northeast, days 



East, days • 



Southeast, days 



South, days 



Southwest, days 



West, days 



Northwest, days . . 



3,793 

 23 rd 

 nth 

 5.1 

 23rd 



nw 

 4 





 

 3 

 2 

 . 3 

 4 

 15 



Weather 



Mean relative humidity, per cent. . 65.1 



Mean cloudiness, per cent 54.0 



Number of clear days 11 



Number of fair days 10 



Number of cloudy days 10 



Number of hours bright sunshine . . 146 

 Percent of possible hours of bright 



sunshine 51.6 



Thunder and lightning 



First snow. Nov. 19th Nov. 5 



30.65 



29.25 



30.056 



1.40 



54.5 

 -2.3 

 27.3 

 56.8 



3.47 

 8.99 



9 



4,726 



6.4 

 29 



69.4 



53.4 



8 



10 



13 



130.7 



46.0 



30.96, 1889 

 28.85, 1915 



1.78, 1895; 1.01, 1892 



65.5, 1908 

 -22.5, 1917 



7.77, 1901; 0.87, 1896 

 26.50, '02; t, 1891 



17, 1902; 4, 1892 

 6,694, 1925; 3,239, 1918 



45, 1934 



71, 1929; 39, 1919 



15, 1890; 2, 1922, 1933 



16, '09; 4. '89, '30, '31, '36 



19, '11, '22; 7, '09, '23 



172, 1896; 63.1, 1933 



Oct. 10, '2.5; Nov. 27, '3l 



NOTK— The first oolunm in the above summary gives observations made during the 

 month. The second column gives the averages based on observations made from 1KW9 

 to 192S. except that humidity record.s are based on observations made from 1929 to 1936. 

 The third column gives extremes observed from 1889 to 1986 



