l^ 



BULLETIN No. 480. 



DECEMBER, 1928 



Meteorolodcal Observations 



o 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



Latitude, 42° 23' 48.5" N. Longitude 72' 31' 10" W. 



Heii^ht of barometer above ground, 36 ft. Abo7>e sea levels ^53-5 f^- 

 Height oj Wind Instnitnents dy ft. Time used, J^th Mer. 



MONTHLY SUMMARY. 



Pressuie. In inches. 



Maximum reduced to freezing, 30.22, 22d, 10 A. 

 Minimum reduced to freezing, 28.84, i8th, 4 A. 

 Reduced maximum reading, 30.53 22d, 10 A. 

 Reduced minimum reading, 29.12, i8th,4 a. 



Mean semi-daily reduced 30.095 



Montlily range 1.41 



Air Tempernture. 



In Degrees Fahr. 



Highest 56.0,17th, II p. 



Lowest 8.5,23rd,6 A.: 24th. 7^ a 



Mean hourly 31.6 



Mean of means of max. and min 324 



Mean sensible (wet bulb) 27.7 



Monthly range 47 5 



Highest mean daily 45.2,17th 



Lowest mean daily ... 16.1,23rd 



Mean maximum 40 6 



Mean niiuinnim 241 



Greatest daily range .'05, 24th 



Least daily range 6.5,20th 



Humidity. 



Mean dew point 229 



Mean force of vapor 173 



Mean relative humidity 77 o 



Wind. 



Total movement 5061 m 



Greatest daily movement 472n"i, 30th 



Least daily movement 34m, 24th 



Mean daily movement 163 m 



Mean hourly velocity 6.8ni 



Maximum pressure per square foot, 13.5 lbs = 



52m per hour, 30th, 11 A. 

 Maximum velocity for 5 minutes, 50m per 



hour, 30th, II A. 



Prevailing direction. West Southwest 



Summary. 



West 32 per cent 



Northwest 23 " " 



South 19 " " 



North Northwest «3 " " 



Other directions 13 " " 



Weather. 



Mean cloudiness observed .... 47 percent 

 1 Otal cloudiness recorded by the Sun 



Thermometer . . 148 hours = 52 per cent 



Number of clear days 9 



Number of fair days 10 



Number of cloudy days I2 



Briitht Sunshine. 



Number hours recorded. 135= 48 per cent. 



Rain. 1st, 3rd, 5th, 8th, 17th, 18th, 20th, 27th, 

 28th. 



Precipitation. In inches. 



Total precipitation, in inches 97 



Number of days on which .01 inch or more 



rain fell 9 



Total snow in inches, 25 



Snow, 8th, 



Gnlea, 35m.. 8th. N.N.VV., 36m., 9th,N.N.W. 

 41m, loth, N.W., 35m., 17th, S.S.E., 

 45m. i8th, W.,42m., 2ist, N.W.,52m., 

 30th, N.N.W. 



