METEOROLOGICAL OBSERVATORY 



OF THE 



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, 2jj.^ ft. 

 Height of Wind Instruments 72 ft. 



BULLETIN No. 133. 



JANUARY, 1900. 



MONTHLY SUMMARY. 



Pressure, In inches. 



Maximum reduced to freezing, 30.35,17th, 9 h. 

 Minimum reduced to freezing, 2S.77, 20th, 12 p. 

 Reducedt maximum reading, 30.67, 17th, 9 p. 

 Reducedt minimum reading, 29. oS, 20th, 12 P. 



Mean tri-daily reduced, 30.034 



Monthly range • 1.58 



*Air Temperature. In Degrees Fahr. 



Highest, 51.5, 23d, 2:30 p. 



Lowest, -4.5, 4th, 7:30 A. 



Mean hourly, 25.5 



Mean of means of max. and min., .... 24.8 



Mean sensible (wet bulb), 23.8 



Monthly range 56.0 



Highest mean daily, 40.2, 23d 



Lowest mean daily 11.7,3d 



Mean maximum, 34.5 



Mean minimum, 15.2 



Mean daily range, ig.3 



Greatest daily range, 34.0, 4th 



Least daily range, 8.0, ist 



Uutnidity. 



Mean dew point, 18. i 



Mean force of vapor, 152 



Mean relative humidity, . . . • ... .75.1 

 Precipitation. In inches. 



Total precipitation, . • 4.0S 



Number of days on which .01 incli or more 



rain or melted snow fell, 15.0 



Snow total in inches, 12.5 



Snow on ground at end of month. . . 4 inches 



* Temperature in ground shelter, 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 4904 m- 



Greatest daily movement, .... 360 m., 27th 



Least daily movement, i5 m., 15th 



Mean daily movement 15S.0 m. 



Mean hourly velocity, 6.6 m. 



Maximum pressure per square foot, 20.5 Ibs.= 



64 m. per hour, 26th, 4:30 p., N.W. 

 Prevailing Direction, West. 

 Summary. 



North, 16 per cent. 



Northwest, 19 " " 



Northeast, 10 " " 



West 13 " " 



South, 19 " " 



Southwest, .' 13 " " 



Other directions, 10 " " 



Weather. 

 Mean cloudiness observed, .... 52 per cent. 

 Total cloudiness recorded by the Sun Ther- 

 mometer, 127 hrs. =43 per cent. 



Number of clear days, 12 



Number of fair days, 10 



Number of cloudy days, 9 



Rright Sunshine. 

 Number of hours recorded, ... 167 hrs.=57K 

 Rain, 7th, 10th, nth, 12th, 14th, i6th, 19th, 



20th, 2ISt, 25th, 26th. 



Snow, ist, nth, 12th, i4th,iSth,2Sth,29th,3ist. 



Sleet, nth. 



Oulfs, 35 miles or more per hour, 37m., 5th, 



S.W.; 48m., 8th, N.W.;35m.,9th, S.W.; 



3gm.,ioth, S.W.; 35m. .nth, N.N.E.; 46 m., 



21st, N.; 36m., 23d, N.W.; 64m., 26th, N.W.; 



;5in., 27th, N.W.; 39m., 29th, N.W. 

 No. days sleighing, n 



