BULLETIN No. 377. 



MAY, 1920 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGIIICULTUIUL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 51 ft. Above sea level^ -^/J-J ft. 

 Height oj Wind Instruments y 2 ft. Time used, y^thMer. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.15, 17th, 8 A 

 Minimum reduced to freezing, 29.42, ist, 5 A 

 Reduced maximum reading . 30.45, 17th, 8 a 

 Reduced minimum reading, 29.72, ist, 5 A 



Mean semi-daily reduced 30.056 



Montlily range 73 



*Air Temperaiure. In Degrees Fahr. 



Highest 83 5, 2Sth, 3 i- 



Lowest 30.5, 5th, 5,30 A 



Mean hourly 54.6 



Mean of means of max. and min 54.5 



Mean sensible (wet bulb) 49. 



Monthly range 53.0 



Highest mean daily 67.6.,^Sth 



Lowest mean daily 41.0, 4th 



Mean maximum 66.5 



Mean minimum 42.6 



Mean daily range 23.9 



Greatest daily range 39.0, 17th 



Least daily range 5.5, 2isl 



HumidKy. 



Mean dew point 44.3 



Mean force of vapor 431 



Mean relative humidity 71.1 



Wind. 



Total movement 3703 m 



Greatest daily movement 207m, loth 



Least daily movement 42m, 24th 



Mean daily movement 120m 



Mean hourly velocity 5.0m 



Maximum pressure per square foot, 5.0 lbs = 



32m per hour, loth, 12 p, N.N.W. 

 Maximum velocity for 5 minutes, 30m per 



hour, 10th, II p, N.N.W. 

 Prevailing direction. West. 



Summary. 



West 16 per cent 



West Northwest 13 



South Southwest 13 



North Northwest : . 10 



Northwest 10 



West Southwest 10 



Southwest 10 



Other directions iS 



Weather. 



Mean cloudiness observed .... 39 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . .172 liours = 38 per cent. 



Number of clear days 14 



Number of fair days 13 



Number of cloudy days 4 



Bright Sunshine. 



Number hours recorded, 281 in's, = 62 per cent. 

 Itain. 1st, 2d, 3d, 4th. jth, 7tli, Sth, 9th, loth. 

 Precipitation. In inches. ,,tl,^ ,3th^ 14th, 20th, 21st, 22d. 



Total precipitation, in inches 3.65 Thunder and I.itihtninu. 14th, 20th. 



Number of days on which .01 inch or mure II ail. 2d, 4tli. 



rain fell iduales. none. 



* Temperature in ground shelter. 

 ♦•Reduced to freezing and sea-level. 



