MONTHLY SUMMARY 



December. 1986 



Normal 



Extremes 



Barometer 



(Readings reduced to sea level) 



Maximum 30.77, 9th 



Minimum 29.36, 20th 



Mean semi-daily 30.265 



Range 1.41 



Air Temperature 



Highest 55, 20th 



Lowest 7, 1st 



Mean 31.8 



Monthly range 48 



Highest mean daily 43.5, 20th 



Lowest mean daily 16.0, 1st 



Mean maximum 39.6 



Mean minimum 24.0 



Greatest daily range 30, 7th 



Least daily range 2, 1 1th 



Precipitation 



Precipitation. In inches 5.96 



Snow, in inches 3.00 



Maximum precipitation in 24 hrs. 



1.38, 20th 

 Number of days on which .01 or more 



inches of precipitation 12 



Wind (miles) 



Total movement 4665 



Greatest daily movement 329, 22nd 



Least daily movement 47, 11th 



Mean hourly velocity 6.3 



Maximum velocity for 5 min., 26, 28th 



Wind (direction) 



Prevailing direction nw 



North, days 8 



Northeast, days 



East, days 1 



Southeast, days 4 



South, days 3 



Southwest, days 1 



West, days 3 



Northwest, days H 



Weather 



Mean relative humidity, per cent . . 70.7 



Mean cloudiness, per cent 62.3 



Number of clear days 11 



Number of fair days ■. 4 



Number of cloudy days 16 



Number of hours bright sunshine . 118 

 Percent of possible hours of bright 



sunshine 41.7 



First snow Nov. 24th 



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 



69.2 

 53.4 

 8 

 10 

 13 

 130.7 



46.0 

 Nov. 5 



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, 1909; 4, 1889,1930,1931 

 19, 1911, 1922; 7, 1909, 1923 



172, 1896; 63.1, 1933 



Oct. 10, '25; Nov. 27, '31 



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

 month. The second column erives the averag-es based on observations n)ade from I8f9 

 to 19-28. except that humidity records are based on observations made from 1929 to 1935. 

 The third column gives extremes observed from 1889 to 1935. 



