BULLETIN No. 372. 



DECEMBER, 1919 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 51 ft. Above sea level, 273-5 A- 

 Height oj Wind Iiistnifuents ^2 ft. 7wte used, y^thMer. 



MONTHLY SUMMARY. 



Pressuie. In inches. 

 Maximum reduced to freezing,3o.35, nth, 11 a 

 Minimum reduced to freezing, 29.10, 7th, i p 

 Reduced maximum reading . 30.67, nth, 11 A 

 Reduced minimum reading, 29.41, 7th, i p 



Mean semi-daily reduced 30.111 



Monthly range 1.26 



*Air Temperainre. In Degrees Fahr. 



Highest 540, 13th, 3 P 



Lowest -9-0, 18th, 7 A 



Mean hourly 23 4 



Mean of means of max. and min 23.2 



Mean sensible (wet bulb) 21.5 



Monthly range 63.0 



Highest mean daily 4S.3. 13th 



Lowest mean daily -0.7, 18th 



Mean maximum 31.7 



Mean minimum 14.7 



Mean daily range 17.0 



Greatest daily range 29.5, 4th 



Least daily range 3.0, 9th 



Hnmidiiy. 



Mean dew point j8.6 



Mean force of vapor 132 



Mean relative humidity 87. i 



Precipitation. In inches. 



Total precipitation, in inches 1.48 



Total snow, in inches 45 



Number of days on which .01 inch or more 



rain fell 12 



Days of sleighing, none. 



•Temperature in ground shelter. 

 ••Reduced to freezing and sea-level. 



Wind. 



Total movement 4022 m 



Greatest daily movement 477m, 25th 



Least daily movement .... 3m, i8tii 



Mean daily movement 130m 



Mean hourly velocity 5-4 m 



Maximum pressure per square foot, 13.0 lbs 



51m per hour, 25th, loA, N. 

 Maximum velocity for 5 minutes, 36m per 



hour, 2;th, 9A, N. 

 Prevailing direction. West Northwest. 



Summary. 



North west 23 per cent 



West 19 



West Northwest 13 



North 13 



North Northeast 10 



Other directions 22 



Weather. 



Mean cloudiness observed .... 39 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 163 hours = 57 per cent. 



Number of clear days 5 



Number of fair days 13 



Number of cloudy days 13 



Bright Sunshine. 



Number hours recorded, 120 hrs,= 43 per cent 

 Rain, 6th. Sth 9th, 12th, 13th, 14th. 

 Snow, 6th, 7th, nth, 14th, 15th, 17th, 21st, 



2''th, 26th, 30th. 

 Hail, I2th. 



Gales, 35 miles or more per hour: 50m, 

 loth, N.W.; 35ni, 15th, W.: 51m, 25th. N. 



