MONTHLY SUMMARY 



DECEMBER, 1949 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 31.104, 25th 



Minimum 29,707, 1st 



Mean semi-daily 30.259 



Range 1.397 



Air Temperature, in Degrees F. 



Highest 61, 22nd 



Lowest — 7, 10th 



Mean 29.9 



Range 68 



Highest mean daily 55, 27th 



Lowest mean daily 5, 10th 



Mean maximum 38.5 



Mean minimum 22.2 



Greatest daily range 28, 10th 



Least daily range 8, 5th, 24th 



Degree-days of heating load for month 1085.5 

 Degree-days cumulative for season. . 2236.6 



Precipitation, in inches 



Precipitation 2.44 



Snow 8.5 



Maximum precip. in 24 hrs 0.68, 12th 



Number of days with .01 or more 13 



Wind, in miles 



Total movement 3751 



Greatest daily movement 302, 29th 



Least daily movement 13, 11th 



Mean hourly velocity 5.0 



Maximum velocity 66, 6th 



Wind, direction 



Prevailing direction NW 



North, days 8 



Northeast, days 3 



F.ast, da}'H 



Southeast, days 5 



South, days 



Southwest, days 4 



West, days 3 



Northwest, days 8 



Weather 



Mean relative humidity, percent 77.6 



Mean cloudiness, percent 48.8 



Number of i. lear days 12 



Number of fair days 6 



Number of cloudy days 13 



Number of hours bright sunshine 11 7.6 



Percent of possible hours of 



br'ghl sunshine 41 .6 



Thunder and lightning 



First Frost 



Normal 



30.66 

 29.27 

 30.06 



1.38 



54.3 

 1.09 



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 

 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 



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. 194S 



71, 1929; 39, 1919 



15, 1890; 0, 1948 



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



25, 1948; 7, '09, '23 



172. 1896; 27, 1948 



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 1948. 



