METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station, 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



Height of barometer above ground, ^r ft. Above sea level, zy^.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 163. 



JULY, 1902. 



MONTHLY SUMMARY. 



fre.nmtre. In inches. 

 .\hi.\unuiii reduced to freezing, 30.00, 7th, 12 M. 

 Miniiniun reduced to freezing, 29.33, '5th, 2 p- 

 Keducedt maximum reading, 30.29, 7th. 12 M. 

 Keducedt minimum reading, 29.61, 151)1, 2 p. 



Mean tri-daily reduced, 29.961 



Monthly range, . . . . • 58 



* Air Te.inperntnre. In Degrees Fahr. 



Highest go-o, Mth, 3 P. 



Lowest, 45.0, 17th, 5 A. 



Mean hourly, 67.8 



.Mean of means of max. and min., . . . .68.3 



Mean sensible (wet bulb), 63.2 



.Monthly range 45.0 



Highest mean daily, 79.0,9th 



Lowest mean daily, 60.6, 20th 



.Mean maximum, 77.9 



Mean minimum, 58.<S 



Mean daily range, 19.1 



Greatest daily range, 35.0, 12th 



Least daily range, 5.0, 20th 



Hutniditt/. 



.Mean dew point 57.3 



Mean forte of vapor, 710 



Mean relative humidity, 77.2 



Precipitfition. In inches. 



Total precipitation, 4.66 



Numter of days on which .01 inch or more 

 rain or melted snow fell, . ...... 13 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement 2929m. 



Greatest daily movement, . . . . 203m., ist. 



Least daily movement, 20m., 21st. 



Mean daily movement, 94.5 ni. 



Mean hourly velocity, 3-9 m- 



Maximum pressure per square foot, 7.5 Ibs.^ 



39 m. per hour, 15th, 5 p., W. 

 Prevailing Ilirection, West. 

 Summary. 



South, 16 per cent. 



West, 16 " 



North, 13 " 



West, Southwest, 13 " 



East, Northeast 10 " 



Other directions 32 " 



Weather. 



Mean cloudiness observed, ....(>(> per cent. 



Total cloudiness recorded by the Sun 'I'her- 



mometer, ..... 277 hrs. = 6o per cent. 



Numter of clear days, 4 



Number of fair days, 11 



Number of cloudy days, 16 



Jiriffht S^inshine. 



Numlier of hours recorded, . . . 1S5 hrs.=4o< 

 Knin, ist, 3d, 5th, 6th, 8th, loth, i;th, 17th, 

 iSth, T9th, 2oth, 21st, 22d, 23d, 24th, 27th. 



Thunder and. Jji^htning, 14th, ijtli, 17th. 



20th, 2ISt, 22d, 24th, 28th. 



Galea, 35 miles or more per hour, 39m., 

 15th, W. 



