BULLETIN No. 439. 



JULY, 1925 



Meteorological Observations 



AT THK 



MASSACHUSETTS 



A«R1CULTU ML EXrERlMENT 



STATION. 



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



Ilcii^ht of barometer above ground, jr ft. Above sea level, 2jj.^ ft. 

 Height oj Wind Instnunents J2 ft. 2'ime used, j^jthMer. 



MONTHLY SUMMARY. 



Pressiiie. In inches. 



Maximum reduced to freezing, 29.87, 9th, 9 a. 

 Minimum reduced to freezing, 29.36, i6tii, 5 p. 

 Reduced maximum reading, 30.16, 9th, 9 A. 

 Reduced minimum reading, 29.64, i6th, 5 p. 



Mean semi-daily reduced 29.923 



Monthly range 0.52 



Air Temperature. In Degrees Fahr. 



Highest 91.5, 7th, 2:30 P 



Lowest 47-5. 'st 5 a 



Mean hourly 69.6 



Mean of means of max. and min 69.1 



Mean sensible (wet bulb) 65.0 



Monthly range 44.0 



Highest mean daily 77.9, 12th 



Lowest mean daily 63.3, 31st 



Mean maximum 79.7 



Mean minimum 5^.6 



Mean daily range 21. i 



Greatest daily range 32.5, i;th 



Least daily range 4.5, 26th 



Hnmiclity. 



Mean dew ])oint 62.3 



Mean force of vapor 706 



Mean relative humidity 81.6 



Preri|>i(a<ioii. Iti inches. 



Total precipitation, in inches 6.97 



Number of days on which .01 inch or more 

 rain fell 13 



Wind. 



Total movement 3292. ni 



Greatest daily movement 24Sm, i6th 



Least daily movement 47m, 20th 



Mean daily movement To6m 



Mean hourly velocity 4.4ni 



Maximum pressure per square foot, 5.5 lbs = 



33m per hour, 7th, 5 p., S.S.W. 

 Maximum velocity for ; minutes, 21m per 



hour, i6th, 12 M., S.W. 

 Prevailing direction. West Southwest. 

 Summary. 



South Southwest 23 per cent 



South 13 " 



Southwest 13 " 



North 10 " 



West 10 " 



West Northwest 10 " 



Other directions 21 " 



Weather. 



Mean cloudiness observed .... 51 percent 

 Total cloudiness recorded by the Sun 



Thermometer . . 174 hours = 38 per cent 



Number of clear days 14 



Number of fair days 11 



Number of cloudy days 6 



Kriiiht Siinsliine. 



Number hours recorded, 2S8 = 62 per cent. 

 Rain. 4th, 5th, 7th, Sth, 10th, i6th. 17th, 21st, 



22d, 25th, 26th, 27th, 28th, 29th, 31st. 

 Thunder and Litibtninii. 7tli, 16th, , 22d, 



25th, 26th. 27th,2Stli. 

 Gales. None. 



