MONTHLY SUMMARY 



December, 1946 



Normal 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum __ 30.59, 31st 



Minimum _ .29.30, 13th 



Mean semi-daily 30.033 



Range 1.29 



Air Temperature, in degrees F. 



Highest - - ^62,, 10th 



Lowest 1, 31st 



Mean .._ 29.9 



Range 62 



Highest mean daily 52, 10th 



Lowest mean daily _ 13.5, 31st 



Mean maximum . _ 39.0 



Mean minimum _.. ._ .20.8 



Greatest daily range 30, 11th. 13th 



Least daily range 6, 21st, 28th 



Precipitation, in inches 



Precipitation . 3.51 



Snow 10.50 



Maximum precip. in 24 hrs. ... 1.89, 20th, 21st 

 Number of days with .01 or more 8 



Wind, in miles 



Total movement 4937 



Greatest daily movement 435, 2nd 



Least daily movement 18, 31st 



Mean hourly velocity 6.6 



Maximum velocity 35, 26th 



Wind, direction 



Prevailing direction WNW 



North, days 7 



Northeast, days .— _._.. 1 



East, days 



Southeast, days 3 



South, days _ -. 6 



Southwest, days ......'.... 1 



West, days 4 



Northwest, days ...9 



Weather 



Mean relative humidity, percent 67.8 



Mean cloudiness, percent 55 



Number of clear days 6 



Number of fair days 8 



Number of cloudy days ...17 



Number of hours bright sunshine 103 



Percent of possible hours of bright 



sunshine 36.4 



Thunder and lightning — 



First snow Dec. 17 



30.66 



29.27 



30.06 



1.38 



54.3 

 -1.9 

 27.5 

 56.2 



3.39 

 8.50 



10 

 4710 



6.3 

 31.4 



WNW 



69.4 



54.9 



8 



9 



14 



128 



45.2 



Extremes 



30.96, 1889 

 28.85, 1915 



1.78, 1895; 1.01, 1892 



65.5, 1908 



-22.5, 1917 



36.9, 1891; 17.L 1917 



7.77, 1901; .58, 1943 

 26.50, '02; t, 1891, 1943 



17, 1902; 4, 1892, 1943 

 6,694, 1925; 3,239, 1918 



48, 1938, 1943, 1944 



71, 1929; 39, 1919 



15, 1890; 2, 1922, 1933 



16, '09; 4, '89, '30, '31, '36, '38 



23, '2,i; 7, '09, '23 



172, 1896; 63, 1933 



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 records are based on observations made 

 from 1929 to 1938. The third column gives extremes observed from 1889 to 1945. 



