METEOROLOGICAL OBSERVATORY 



OF THE 



llatcli Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of Ihx romcfcr above ground, 31 ft. Above sea level, 2JJ.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 138. JUNE. I 90Q. 



MONTHLY SUMMARY. 



Pressure. In inches. 



Maximum reduced to freezing, 29.90, I'jtli, 7 a. 

 Minimum reduced to freezing, '•.9. 23,2Stli, 5:301'. 

 Keducedt maximum reading, 30.19, 13th, 7 a- 

 Keducedl minimum reading, 29.51, 28111,5:30 p. 



Mean tri-daily reduced, 29.907 



Montlily range • 67 



*Air Temperature. In Degrees Fahr. 



liigliest, 94.0,27th, IP. 



Lowest, 40.0, 5th, 5 A. 



Mean liourly, 67.1 



Mean of means of max. and min., .... 67.1 



Mean sensiljle (wet IjuIIj), 61.7 



Montlily range 54.0 



Highest mean daily 75.8, 27th 



Lowest mean daily 59.0, 3d 



Mean maximum, S0.5 



Mean minimum, 53.6 



Mean daily range, 26.9 



Greatest daily range, 44.0, 5th 



Least daily range, 14.0, 3d 



llutititlitif. 



Mean dew point, 57.0 



Mean force of vapor, 732 



Mean relative humidity, . . . • 



Wi}id. 



Total movement, 4101m. 



Greatest daily movement, .... 320 m., 30th 



Least daily movement, 34ni., ist 



Mean daily movement, 136.7 m. 



Mean hourly velocity, 5-7 in- 

 Maximum pressure per scjuare foot, 12.5 Ihs.^ 



50 m. per hour, 30th, 2:30 P., N.W. 

 Prevailing Direction, W.S.W. 



Summary. 



Southwest, i7per cent. 



South Southwest, 23 " " 



West, 13 " " 



Other directions, 47 " " 



Weather. 



Mean cloudiness observed, .... 49 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 19S hrs.=43 per cent. 



Number of clear days, 6 



Number of fair days, 15 



Number of cloudy days, 9 



Itriylit Sunshine. 



Number of hours recorded, . . . 259 hrs.=57?t 

 ( . Rain, 1st, 3d, 8th, nth, 14th, 19th, 22d, 23d, 

 27th, 2Sth. 



frecipifiition. In inches. 



Total precipitation, . • 3.65 



.N'umber of days on wiiich .01 inch or more 

 rain or melted snow fell, S 



* Temperature in ground shelter. 

 f Reduced to freezing and sea-level. 



Tliunder anil Lh/litiiing, 2d, iith,2Sth. 



Hall, 2Sth. 



Gales, 35 miles or more per hour, 44m., 27th, 



S. S. \V. ; 45m., 2Sth, S. W.; 5oni., 30th, 



N. \V. 



