METEOROLOGICAL OBSERVATORY 



Hatch Experiment Station 



MASSACHUSETTS AGRICULTURAL COLLEGE 



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



Height of barometer above ground, 51 ft. Above sea level, 2YJ.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 145. 



JANUARY, 1901 



MONTHLY SUMMARY. 



Vressure. In inches. 

 Maximum reduced to freezing, 30.36, 3d, 10 A. 



2otii, 9 A. 

 Minimum reduced to freezing, 2S.69, 28th, i A. 

 Reduced! maximum reading, 30.69, 3d, 10 A- 



20th, 9 A. 



Keducedt minimum reading, 29.01, 28th, i .\- 



Mean tri-daily reduced, 29.953 



Monthly range • 1.68 



*Air Temperature. In Degrees Fahr. 



Highest, 47.0, 9th, 3:30 p. 



Lowest, —8, 20th, 6 A. 



Mean hourly, 23.7 



Mean of means of max. and min., .... 23.6 



Mean sensible (wet bulb), 22.1 



Monthly range, 55.0 



Highest mean daily, 37.0, i6th 



Lowest mean daily 2.5, 19th 



Mean maximum, 32.7 



Mean minimum 14.5 



Mean daily range 18.2 



Greatest daily range, 34.0, 20th 



Least daily range, 7.0, loth, 12th 



Huitiiditji. 



Mean dew point, 16.6 



Mean force of vapor, 141 



Mean relative humidity, 74.3 



Precipitation. In inches. 



Total precipitation, . ■ 1.81 



Number of days on which .01 inch or more 



rain or melted snow fell 10 



Snow, Total in inches, 12.0 



Snow on ground at end of month, .... 2.0 

 * Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 5224m. 



Greatest daily movement, .... 460 m., 26th 



Least daily movement, 27 m., 14th 



Mean daily movement 168.5 rn- 



Mean hourly velocity, 7.0 m. 



Maximum pressure per square foot, 12.5 lbs.= 



49 m. per hour, 19th, 2 P., N.W. 

 Prevailing Direction, West. 

 Summary. 



North, Northwest, 23 per cent. 



Northwest, 13 " " 



West, . • 13 " " 



South, 13 " " 



South, Southwest, 10 " " 



North, 10 " " 



Other directions iS " " 



Weathei-. 

 Mean cloudiness observed, .... 58 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, i77hrs.=6o per cent. 



Number of clear days, 6 



Number of fair days, 9 



Number of cloudy days, 16 



liriyht Sunshine. 

 Number of hours recorded, . . ii7hrs.=40)t 

 Rain, 9th, loth, i6th, 21st, 23d. 



Sleet, loth. 

 Snow, 2d, 7th, loth, nth, 12th, 14th, 15th, 



i6th, 17th, iSth, 19th, 2Sth, 30th, 31st. 

 Oales, 35 miles or more per nour, 35m., ist, 

 W.N. W.; 42 m.. 2d, W.; 41 m., 12th, N. 

 W.; 49m., 19th, N.W.; ^6m.. 20th, S.: 

 46m., 26th, N.N.W.; 39m., 29th, W. 

 No. days sleighing • . . . . 19 



