METEOROLOGICAL OBSERVATORY 



OF thp: 



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, syj.^ ft. 

 Height of IVlnd Instrutnents 72 ft. 



BULLETIN No 217 



JANUARY, I907. 



MONTHLY SUMMARY. 



Pressure, In inches. 



Maximum reduced to freezing, 30.41, 31st, 8 A.; 

 Minimum reduced to freezing, 29.10, 20th, i p. 

 Reducedt maximum reading, 30.75, 31st, 8 A.f 

 Reducedt minimum reading, . 29.41, 20th, i p. 



Mean semi-daily reduced, 30.230 



Monthly range 1-34 



*Air Temperature. In Degrees Fahr. 



Highest, 54.5.7th, 3 P- 



Lowest —23-5. 24th, 7:00 a. 



Mean hourly, 22.4 



Mean of means of max. and min., .... 22.1 



Mean sensible (wet bulb), 1S.8 



Monthly range 78.0 



Highest mean daily, 41.4,4th 



Lowest mean daily, —8.0, 24th 



Mean maximum, 3°-9 



Mean minimum, i3-3 



Mean daily range i7-6 



Greatest daily range 34-o. .'^>ist, 



Least daily range, \.o, 8th 



Hnmidity. 



Mean dew point i3-4 



Mean force of vapor, 130 



Mean relative humidity, 76.1 



Precipitation. In inches. 



Total precipitation, 2.73 



Number of days on which -oi inch or more 



rain or melted snow fell 12 



Total snow in inches 161 



* Temperature in ground shelter. 

 t Reduced to freezing and sea-level. 



Wind. 



Total movement, 4987 m. 



Greatest daily movement, . . . . 46Sm. ,20th 



Least daily movement, 37m., iSth, 



Mean daily movement 161 m. 



Mean hourly velocity, 6.7 m. 



Maximum pressure per square foot, 14.0' lbs. = 

 53 m. perhour, 9th, loA., W.N.W. 



Maximum velocity for 5 minutes, 36 m. per 



hour 9th, 2 p., W.N.W. 

 Prevailing Direction, North, Northwest. 



Summary. 



Northwest, 23percent. 



North, Northeast, 16 " 



North, Northwest, 10 " " 



North, 10 " " 



Other directions, 41 " " 



Weather. 



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



Total cloudiness recorded by the Sun 1'her- 



mometer, . . . i64hrs. = 56 per cent. 



Number of clear days 7 



Number of fair days 11 



Number of cloudy days, 13 



Bright Sunshine. 



Number of hours recorded, . . 130 hrs.=44* 

 Rain, 3d, 4th, 7th, Sth, 12th, 14th, iSth, 19th, 



2cth, 



Snow,Sth, 12th, 14th, 17th, i8th, 19th, 22d, 

 25th, 26th, 30th. 



nays Sleighing . 18. 



Onles, 3; miles or more per hour, 44 m. 4th, 

 N.N.W.; 53 m. 9th, W.N.W. ; 41 m. 20th, 

 N.W.; 37 m. 2ist, N.N.W. 



