MONTHLY SUMMARY 



December, 1947 



Barometer, in inches 



(Readings reduced to sea level) 



Alaximum 30.47, 1st 



Minimum 29.25. 16th 



Mean semi-daily 30.014 



Range 1.22 



Air Temperature, in degrees F. 



Highest 52. 3rd 



Lowest .' 0, 25th 



.Mean 25 6 



Range 52 



Highest mean daily 42.5, 16th 



Lowest mean daily 15, 29th, 30th 



Mean maximum 34.3 



Mean minimum 16.8 



Greatest daily range 28, 15th 



Least daily range 2, 23rd 



Precipitation, in inclies 



Precipitation 2.33 



Snow 17.50 



Maximum precip. in 24 hrs 0.53, 2()th 



Number of days with .01 or more 11 



Wind, in miles 



Total movement 4849 



Greatest daily movement 480, 9th 



Least daily movement 19, 2nd 



Mean hourly velocity 6.5 



Maximum velocity 40, 9lh 



Wind, direction 



i'revalling direction NW 



North, days 8 



Northeast, days 



East, days 1 



Southeast, days 2 



South, days 2 



Southwest, days 



VV est, days 4 



Northwest, days 14 



Weather 



Mean relative humidity, percent 66.6 



Mean cloudiness, percent 11 



Number of clear days 7 



Number of fair days 10 



Number of cloudy days 14 



Number of hours bright sunshine 115 



Percent of possible hours of 



bright sunshine 40.6 



Thunder and lightning — 



First Snow Dec. 3 



30.66 



29.27 



30.06 



1.38 



54.3 



27.5 

 56.2 



3.39 

 8.50 



4710 



6.3 

 31.4 



WNW 



69.4 

 54.9 



8 



14 



128 



45.2 

 Nov. 6 



Extremes 



30.96. 1889 

 28.85, 1915 



1.78, 1895; 1.01, 1892 



65.5, 1908 



— 22.5, 1917 



36.9, 1891; 17 1, 1917 



1.11. 1901; .58, 1943 

 26.50. '02, T, 1891, 1943 



17, 1902; 4, 18<)2, 1943 



6,694, 1925; 3,239. V)\\ 



48, 193S, 1943. 1944 



71, 1929; 39, 1919 



15, 1890; 2, 1922, 1933 



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



23, '33; 7, '09, '23 



172. 1896; 63, 1933 



Note — The first column in the above summary gives observations rnade 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 1946. 



