BULLETIN No. 475. 



JULY, 1928 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, 36 ft. Above sea level, 2jj.j ft. 

 Height oj Wind Instruments dy ft. Time used, 7^th Mer. 



MONTHLY SUMMARY. 



Pressuie. In inches. 



Maximum reduced to freezing, 29.96, 31st, 8 A. 

 Minimum reduced to freezing, 29.40, 28tli, 6 P. 

 Reduced maximum reading, 30.24, 31st, 8 A. 

 Reduced minimum reading, 29.67, 28tlr,6 p. 



Mean semi-daily reduced 29.949 



Montlily range 57 



Air Temperature. In Degrees Fahr. 



Highest 93.0,8th, 4-30? 



Lowest 47.0, 31st, 5 .\ 



Mean hourly 71.5 



Mean of means of max. and min 70.3 



Mean sensible (wet bulb) 66.S 



Monthly range 46.0 



Highest mean daily 77.5, jgth 



Lowest mean daily 61.7, 3olh 



Mean maximum 82.4 



Mean minimum 61.7 



Greatest daily range 33.0, Sth, 31st 



Least daily range 7.0, 27th 



Huniidily. 



Mean dew point 648 



Mean force of vapor 761 



Mean relative humidity So. 6 



Precipitation. In inches. 



Total precipitation, in inches 6.23 



Number of days on which .oi inch or more 

 rain fell >4 



Wind. 



Total movement 354';ni 



Greatest daily movement 294ni, 29th 



Least daily movement 37m, 2nd 



Mean daily movement 114m 



Mean hourly velocity 4.7ni 



Maximum pressure per square font, 6.olbs = 



35)n per hour, loth, 6 P. 

 Maximum velocity for 5 minutes, 27m per 



hour, 29th, 12:30 P. 



Prevailing direction. South 

 Summary. 



South Southeast 26 per cent 



South Southwest 13 " 



West Northwest 13 " 



East Southeast 10 " 



Northwest 6 " 



North Northeast 6 " 



South 6 " 



West Southwest 6 " 



Other directions 14 " 



Weather. 



Mean cloudiness observed .... 50 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 213 hours = 40 per cent 



Number of clear days 11 



Number of fair days 5 



Number of cloudy days 15 



Briiiht Sunshine. 



Number hours recorded. 249=- 54 per cent. 



Rain, ist, 2nd, 5th, 6th, gth, loth, nth, 12th, 



13th 14th, 19th, 20th, 22nd, 23rd, 



24th, 27th 28th. 

 Thunder and Liiihtninti. 1st, 9th, loth, 12th, 



27th. 

 Gales, 35 or mure miles per hour: 35m, loth, 



SE. 



