inc 



LIBRAHY ur 

 v^nssachnsetts AericuUural Co\leU' 

 AMHERST, MASS. 



BULLETIN No. 437. 



MAY, 1925 



Meteorological Observations 



AT THK 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Ht'ii^ht of ha >-o meter abcwe ground, ^i ft. Above sea level, 2yj.^ ft. 

 Height oj Wind Instruments J 2 ft. Time used, j^th Mer. 



MONTHLY SUMMARY. 



Pressiite. 1» inches. 



Maxiimiui reduced to freezing:, 30.04, i6th,SA. 

 Minimuni reduced to freezinfj;, 29.16, 2jd. 6 p. 

 Reduced maximum reading, 30.34 16th, S A. 

 Reduced minimum reading, 29.45, 23d, 6 p. 



Mean semi-daily reduced 29.935 



Monthly range o S9 



Air Temperature. 



In Degrees Fahr. 



Highest So.o, 2ist. 1:30 p. 



Lowest . . .' 30.5, 26th 6 A. 



Mean hourly 54.6 



Mean of means of max. and min 54 



Mean sensible (wet bulb) 50.1 



Monthly range 49.5 



Highest mean daily 62.S, 17th 



Lowest mean daily 4.44, 25th 



Mean maximum 66.6 



Mean minimum 41.5 



Mean daily range 25.1 



Greatest daily range 37.0, 27th 



Least daily range 8.0, 24th 



Humidity. 



Mean dew point 46.7 



Mean force of vapor 418 



Mean relative humidity 79.3 



Precipitation. In inches. 



Total precipitation, in inches 2.55 



Number of days on which .01 inch or more 

 rain fell 12 



Wind. 



Total movement 4005m 



Greatest daily movement 280m, 17th 



Least daily movement 40m, 28th 



Mean daily movement 129m 



Mean hourly velocity 5.2m 



Maximum pressure per square foot, 6.0 lbs = 



35ni per hour, 21st, 5 p., N.W. 

 Maximum velocity for 5 minutes, 24m per 



hour, 2ist, 3 p., W. 

 Prevailing direction. West Southwest. 



Summary. 



South 19 per cent 



South Southwest 16 " 



Southwest 13 " 



North 13 " 



West 10 " 



Other directions 29 " 



Weather. 



Mean cloudiness observed .... 54 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . .211 hours = 47 per cent. 



Number of clear days 5 



Number of fair days 16 



Number of cloudy days 10 



Itriiiht Sunshine. 



Number hours recorded, 242 = 53 per cent. 

 Rain. 1st, 2d, 4th. 6th, nth. 14th, 15th, 17th, 



2ist, 23d, 24th, 25th, 29th, 30th, 31st. 

 Frosts. Sth, 19th, 26th. 



Thunder and Liiihtninii 17th, 24tii 3otii 

 Gales, 35m, 21st, N.W.; 



