BULLETIN No. 420. 



DECEMBER. 1923 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGllICULTUML EXPERIMENT 



STATION. 



Latitude, 42" 23' 48.5" N. Longitude 72* 31' 10" VV. 



Height 0/ ha ro meter above ground, jr ft. Above sea le7<el, 2yj.^ ft. 

 Height oj Wind Instruments 72 ft. Time used, y^th Mer. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 30.49, T5th 8.\ 

 Minimum reduced to freezing, 28.98, 28th. 12 m 

 Reduced maximum reading, 30.81, 15th 8a. 

 Reduced minimum reading, 29.29, 28th, 12 M 



Mean semi-daily reduced 30.035 



Monthly range 1.51 



Air Temperatare. In Degrees Fahr. 



Highest 57.0,6th, 1:30 P.; 13th, 8 p. 



Lowest 7.0, 30th, 7:30 A 



Mean hourly 34:7 



Mean of means of max. and min 34.S 



Mean sensible (wet bulb) 31.7 



Monthly range 50.0 



Highest mean daily 46.9,13th 



Lowest mean daily 16.6, 30th 



Mean maximum 42.1 



Mean minimum 27.4 



Mean daily range 14.7 



Greatest daily range 24.0, 21st 



Least daily range 5.0, 23d 



Hniiiidity. 



Mean dew point 26.3 



Mean force of vapor 198 



Mean relative humidity 77.4 



Precipitation. In inches. 



Total precipitation, in inches 4.23 



Total snow, in inches 9J 



Number of days on which .01 inch or more 



rain fell 14 



Days of sleighing 4 



Wind. 



Total movement 4428m 



Greatest daily movement 314m, 14th 



Least daily movement 31m, 22d 



Mean daily movement 143m 



Mean hourly velocity 6.0m 



Maximum pressure per square foot, 9.5 lbs = 



44ni per hour, 6th, 3 p., S.E. 

 Maximum velocity for 5 minutes, 30m per 



hour, 6th, 2 p., S. E. 

 Prevailing direction, West, Northwest. 



.Summary. 



North 23 per cent 



Northwest 13 " 



South Southwest 13 " 



South 16 " 



North Northaest 10 " 



Other directions 25 " 



Weather. 



Mean cloudiness observed .... 52 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 121 hours = 43 per cent. 



Number of clear days 9 



Number of fair days 15 



Number of cloudy days 7 



Bright Sunshine. 



Number hours recorded, 162 = 57 per cent. 

 Rain, 2d, 5th, 6th, qth, inth, iith, 13th, 20th, 

 22nd, 2'!rd, 24th, 31st. 



Snow . . 14th, 24th, 25th, 2Sth 29th. 30th 31st 

 Gales. 44 m, 6th.; S. E. : 36 m, 13th, N.; 35 m. 

 14 th, N. N. W.; 36 m., 17th, \V.;35 m. . 28th, 

 W.; 40 m. , 29th, N. W. 



