BULLETIN No. 387. 



MARCH. 192 1 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGIIICULTUIUL EXPEKIMENT 



STATION. 



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



Height of barometer above ground, ^i ft. Above sea level, ^yj.j ft. 

 Height oj Wind Instrulnents ^2 ft. Time used, y^th Mer. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.34, 23d, 8 A 

 Minimum reduced to freezing, 29.35, 28th, 4 p 

 Reduced maximum reading . 30^5, 23d, 8a 

 Reduced minimum reading, 29.64, 28th, 4 p 



Mean semi-daily reduced 30-i5i 



Monthly range i-oi 



*Air Temperature. 



In Degrees Fahr. 



Highest 79.5,21st, II A 



Lowest 16.0, 5th, 6 a; 19th 6 a 



Mean hourly 42.7 



Mean of means of max. and min 42.5 



Mean sensible (wet bulb) 37-9 



Monthly range 63.5 



Highest mean daily 61.3. 21st 



Lowest mean daily 24.5, 5th 



Mean maximum 53-3 



Mean minimum 3' -8 



Mean daily range 21.5 



Greatest daily range 42.0, 28th 



Least daily range 6.0, 8th 



Hnmidity. 



Mean dew point 32.9 



Mean force of vapor 274 



Mean relative humidity 72.4 



Precipitation. In inches. 



Total precipitation, in inches 3.57 



Number of days on which .01 inch or more 



rain fell 16 



•Temperature in ground shelter. 

 ••Reduced to freezing and sea-level. 



Wind. 



Total movement 6486 m 



Greatest daily movement 3S8m, 25th 



Least daily movement 45m 8tli 



Mean daily movement 209m 



Mean hourly velocity 8.7 ni 



Maximum pressure per square foot, 12.5 lbs = 



50m per hour, 29th, 2 A, N. 

 Maximum velocity for 5 miViutes, 2Sm per 



hour, 29th, I A, N. 

 Prevailing direction. West Southwest. 



Summary. 



South Southwest 36 per cent. 



North 13 " 



Northwest 10 " 



North Northwest ....'.... 10 " 



West Southwest 10 " 



Other directions 21 " 



Weather. 



Mean cloudiness observed .... 59 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 164 hours = 44 per cent. 



Number of clear days 7 



Number of fair days 12 



Number of cloudy days 12 



Bright Sunshine. 



Number hours recorded, 207, = 56 per cent. 

 Rain, 2d, 3d, 5th. 6th, 7th, 8th, gth, 12th, 13th, 



15th, i6th, 19th, 20th, 24th, 25th, 26th, 28th, 



31st. 

 Thnnder and L,i<ihtninii. 8th, 19th, 28th. 

 Gales. 35m. 9th, S.S.W.; 39m, iSth, W.N.W.: 



39m. 21st, W.N.W.; 36m. 22d, N.; 42m. 



25th, S.; 50m. 29th, N.; 4ini. 31st, S. 



