BULLETIN No. 329. 



MAY, 1916 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



He{^ht flf barometer above ground, 31 ft. Above sea level, 2jj.^ ft. 

 Height oj Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.02, 14th, 8 a 

 Minimum reduced to freezing, 28.92, 17th, 

 Reducedt maximum reading, 30.32, 14th, 8 A 

 Reducedt minimum reading, 29.22, 17th, 3 p 



Mean semi-daily reduced 29.907 



Monthly range i.io 



*Air Temperature. In Degrees Fahr 



Highest 81.5, 29th, 2:30 p 



Lowest 36.0, loth, 4:30 .■\ 



Mean hourly 55.9 



Mean of means of max. and min 56.2 



Mean sensible (wet bulb) 50.4 



Monthly range 45.5 



Highest mean daily 67.4, 29th 



Lowest mean daily 46.S iSth, 23d 



Mean maximum 66.7 



Mean minimum 45.7 



Mean daily range 21.0 



Greatest daily range 36.5,21st 



Least daily range 5.0, 23d 



Humidity. 



Mean dew point 45.1 



Mean force of vapor 448 



Mean relative humidity 71.9 



Precipitation. In inches. 



Total precipitation 321 



Number of days on which .01 inch or more 



rain fell 12 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 4893 m 



Greatest daily movement 449ni, nth 



Least daily movement 45ni, i6th 



Mean daily movement 158 m 



Mean hourly velocity 6.6 m 



Maximum pressure per square foot, 19.0 lbs := 



62 m per hour, 12th, i A, W.N.W. 

 Maximum velocity for 5 minutes, 36m per 



hour, nth, i p, S.S.W. 

 Prevailing direction, West Southwest. 



.Summary. 



North Northwest 10 per cent 



South Southwest 26 " " 



West 19 " " 



West Northwest 13 " " 



Other directions 32 " " 



Weather. 



Mean cloudiness observed .... 53 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 272 hours = 60 per cent 



Number of clear days 4 



Number of fair days 14 



Number of cloudy days 13 



Bright Sunshine. 



Number hours recorded, 191 hrs, = 40 per cent 



Rain. 2d, 4th, 6th, 7th, 8th, 15th, 16th, 17th, 23d, 

 24th, 27th, 2Sth, 29th, 30th. 



Thunder and Lightning, 4th. Sth, 2Sth, 

 30th. 



Frosts. 19th. 



Gales, 35 or more miles per hour: 35m, 2d, 

 N.; 47m, 8th, S.S.W.; 40m, 9th, W.S.W.: 

 6im, iith,W.; 6?m, 12th, W.N.W.; 42m, 

 17th, N.W.; 35m, 25th, W.N.W. 



