METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



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



//c'/i;/// of barometer above ground, 51 ft. Above sea level, 2'/j.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 15 1. JULY, I9QI. 



MONTHLY SUMMARY. 



I'reasnre. In inches. 

 Mrixinnini reduced to freezing, 30.00, i3tli,9A. 

 Minimum reduced to freezing, 29.42, 7th, 4 P. 

 Keducedt maximum reading, 30.29, i3tli, 9 A. 

 Keducedt minimum reading, 29.70, 7th, 4 r. 



Mean tri-daily reduced, 29.929 



Monthly range, . . . . • 59 



*Air Temperature. In Degrees Fahr. 



Highest, 100.5, 2d,i-3o P. 



Lowest, 48., 5 13th, 5 A. 



Mean hourly, 72.5 



Mean of means of max. and niin 73.3 



Mean sensible (wetljulb), 67.2 



Monthly range 52.0 



Highest mean daily, 83.9, ist 



Lowest mean daily, 61.9,25th 



Mean maximum, 84. 5 



Mean minimum, 62.0 



Mean daily range, -22.5 



Greatest daily range, 36.0, i3tli 



F-east daily range, 8.0, 6th, 9th, 29th 



lliitniditif. 



Mean dew point, 63.4 



.Mean force of vapor, 837 



Mean relative humidity, 72.3 



I'reclpitfitioH. In inches. 



Total precipitation, . ■ 3.86 



Number of days on which .01 inch or more 

 rain or melted snow fell, 14 



* Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



in ml. 



Total movement, 2763m. 



Greatest daily movement, .... 206 m., 28th 

 Least daily movement, ...'... 25 m., 26th 



Mean daily movement, 89.1 ni. 



Mean hourly velocity, 3-7 ni. 



Maximum pressure per square foot, 14,5 lhs.= 



54 m. per hour, 2d, 4 P., W. 

 Prevailing Direction, Southwest. 



Summary. 



South, 23 per cent. 



West, 19 " " 



Soutli Southwest, 10 " " 



South Soutlieast, 10 " " 



Otiier directions 38 " " 



ll'^enther. 



Mean cloudiness observed, .... 63 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 254 hrs.=55 per cent. 



Xuml)er of clear days, 7 



Numijer of fair days, h 



Number of cloudy days, 13 



UriffJit Sunshine. 



Number of hours recorded, . . . 20S hrs.=45)( 

 Rain, 2d, 4th, 5th, 6th, 9th, loth, 17th, 21st, 

 24th, 25th, 26th, 28th, 29th, 30th. 



dales, 35 miles or more per hour, 54ni., 2d, 

 W. 



Thunder and TAghtninfj, 2d, 4th, 5th, 6th, 

 loth, i6th, 17th, iSth, 2ist. 



