BULLETIN No. 355. 



MAY, !9I9 



Meteorological Observations 



AT THE 



MASSACHUSETTS 



AGRICULTURAL EXPERIMENT 



STATION. 



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



Height of barometer above ground, jr ft. Above sea level, 2yj.^ ft. 

 Height oj Wifid Instriime/its ^2 ft. Time used, y^thMer. 



MONTHLY SUMMARY. 



Pressure. In inches. 

 Maximum reduced to freezing, 30.14, 6th, 8 A 

 Minimum reduced to freezing, 29.45, iSth, 9 A 

 Reduced maximum reading . . 30.44,6th, 8 A 

 Reduced minimum reading, 29.74, i8th, 9 A 



Mean semi-daily reduced 29.9S0 



Monthly range 0.70 



. *Air Temperature. In Degrees Fahr. 



Highest 89.0, 29th, 3 P 



Lowest '. 33.0, ist, 6 A 



Mean hourly 57-6 



Mean of means of max. and min 57.4 



Mean sensible (wet bulb) 51.7 



Monthly range 56.0 



Highest mean daily ? 69.4, 29th 



Lowest mean daily 43.3, nth 



Mean maximum 69 4 



Mean minimum 45.5 



Mean daily range 23.9 



Greatest daily range 41.0, 29th 



Least daily range 5.5, 22d 



Humidity. 



Mean dew point 47.0 



Mean force of vapor 480 



Mean relative humidity 70.8 



Precipitation. In inches. 



Total precipitation, in inches 6.20 



Total snow, in inches Trace 



Number of days on which .01 inch or more 



rain fell 16 



•Temperature in ground shelter. 

 ♦•Reduced to freezing and sea-level. 



Wind. 



Total movement 4290 m 



Greatest daily movement 244ni, 5th 



Least daily movement 84m, 7th 



Mean daily movement 138m 



Mean hourly velocity 5.8 m 



Maximum pressure per square foot, 5.5 lbs 



33m per hour, 5th, 12M, W.N.W. 

 Maximum velocity for 5 minutes, 27m per 



hour, 5th, I2M, W.N.W. 

 Prevailing direction, Northwest. 



Summary. 



North 23 per cent 



North NortheastI 16 " " 



South Southwest 10 " " 



West Southwest 10 "' " 



West 10 " " 



Other directions 31 " " 



Weather. 



Mean cloudiness observed .... 50 per cent 

 Total cloudiness recorded by the Sun 



Thermometer . . 171 hours = 38 per cent. 



Number of clear days 15 



Number of fair days 9 



Number of cloudy days 7 



Bright Sunshine. 



Number hours recorded, 282 hrs,= 62 per cent. 

 Rain. 1st, 2d, 4th, 5th, 7th, gth.ioth, nth, 12th 



15th, i-'th, 2ist, 22d, 24th, 25th, 26th. 

 Frost. ISt. 



Thunder and Liiihtninii, 4fh. 

 Gales. 35 miles or more [jer hour : None. 



