BULLETIN No. 316. 



APRIL. 1915 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGKICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, ^i ft. Above sea level, 2YJ.^ ft. 

 Height of Wind Instruments 72 ft. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 30.21, 22d, 8 A. 

 Minimum reduced to freezing, 29.24, 29th, 5 p. 

 Reducedt maximum reading, 30.51. 22d, 8 a 

 Reducedt minimum reading, 29.52, 29tli, 5 p. 



Mean semi-daily reduced, 3o-034 



Monthly range 0.99 



•Air Temperature. In Degrees Fahr. 



Highest 88.0, 25th, 3P.; 



27th, 4:30 P. 



Lowest 21.5, 5tl:, 6a. 



Mean hourly, 49-9 



Mean of means of max. and min 51.1 



Mean sensible (wet bulb), 43 4 



Monthly range, 66.5 



Highest mean daily 70-9. 27th 



Lowest mean daily, 30.1,3d 



Mean maximum, 63-o 



Mean minimum, 39-2 



Mean daily range 23.8 



Greatest daily range 42.5, 25th 



Least daily range 8.0, 3d 



Humidity. 



Mean dew point, 37-5 



Mean force of vapor, 362 



Mean relative humidity, 67.8 



Preciiiitation. In inches. 



Total precipitation 3-99 



Number of days on which .01 inch or more 



rain fell 7 



Total snow in inches 9-5 



♦Temperature in ground shelter. 

 1 Reduced to freezing and sea-level. 



Wind. 



Total movement, 5i95ni. 



Greatest daily movement, .... 461m., 4th 



Least daily movement, S3in.. 6th 



Mean daily movement I73ni. 



Mean hourly velocity, 7.2 m. 



Maximum pressure per square foot, 12.5 lbs.= 



50m. per hour, "^d, loP., N. 

 Maximum velocity for 5 minutes, 33m. per 



hour, i2th, ioa., S.S.W. 

 Prevailing Direction, Northwest. 



Summary. 



Northwest 13 per cent. 



North Northwest 17 " " 



South Southwest 17" " 



North Northeast 17" " 



Other directions 36 " " 



Weather. 



Mean cloudiness observed, . . . .46 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 179 hrs. =44 per cent . 



Number of clear days, 4 



Number of fair days, 18 



Number of cloudy days 8 



Bright Sunshine. 



Number of hours recorded, . .223 hrs=56^. 



Rain, 6th, loth, nth, 12th, 22d, 23d, 27th, 28th, 



29th, 30th. 



Snovp, 2d, 3d. 



Thunder and Liglitning:, loth, nth, 25th, 



27th, 29th, 30th. 



Frosts, 3d, 5th, 22d. 



Gales, 35 or more miles per hour : 50m., 3d, 

 N.; 40m., 4th, N.; 44m , 12th, S.S.W.; 

 44m., iSth, N.; 36m., 20th, N.; 36m., 

 2ist, N.N.E.; 40m., 22d, E.N.E. 



