METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of Ihxrometer above ground, 31 ft. Above sea level, ^yj.^ ft. 

 Height of Wind Instruments 72 ft. 



MAY, 1902. 



BULLETIN No. 161. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 .M.ixniuini reduced to freezing, 30.14. 31st, q .a. 

 Minimum reduced to freezing, 29.21, 27th, 6 i'. 

 Reducedt maximum reading. 30.43. 31st, g A 

 Reducedf minimum reading, 29.49, 2;th, 6 r 



Mean tri-daily reduced 29.939 



Montlily range • 94 



*Air Tenijterature. In Degrees Falir. 



Highest, gi.o. 23d, 4r 



r.owest, 30.0, loth, 5 A., 12th, 5 .-\ 



-Mean hourly, 57.0 



Mean of means of max. and mm., .... 56.6 



Mean sensiljle (wet bulb), 50. S 



.Monthly range 61.0 



Highest mean daily, 73.9, 23d, 24th 



Lowest mean daily 41.7,10th 



Mean maximum, 69.3 



Mean minimum, 43.9 



Mean daily range, 25.4 



Greatest daily range, 44.0, iSth 



[.east daily range, 8.5, 3d 



Ifiiin iiliti/. 



Mean dew point 44.0 



Mean force of vapor, 512 



Mean relative humidity, 1)3.4 



Precipitation. In inches. 



Total preciintatinn, 2.32 



Number of days on which .01 incli or more 

 rain or melted snow fell, <S 



• Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 432Sm. 



Greatest daily movement 341m. ,9th. 



Least daily movement iSni., 19th. 



^1ean daily movement, 139.6 ni. 



Mean hourly velocity, 5.8 m. 



Maximum pressure per square foot, 10.0 lbs. = 



45 m. per hour, gth, 3 p., N. 

 Prevailing Direction, North, Northwest. 

 Summary. 



North 23 per cent. 



North, Northeast 13 



Northeast, 13 



West, 13 



Northwest, 10 



Other directions 2S 



Weather. 



Mean cloudiness observed, . . . . 58 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, .... 243 hrs.= 54 per cent. 



Number of clear days, 6 



Number of fair days, g 



Number of cloudy days, 16 



Jiright Sunshine, 



Number of hours recorded, . . . 210 hrs. =4651 

 Rain, 3d, 4th, 5th, 14th, igth, 24th, 25th, 26th, 

 27th, aSth, 29th, 30th. 



Frosts, i2th, 14th. 



Tfiuniirr and Lightning, 4th, 24th, 26th, 

 27th. 



Gales, 35 miles or more per hour, 35m., 

 Sth. N. : 45m., gth, N.: 35m., 24th, W. 



