No. 4.] MASSACHUSETTS WEATHER. 



XXXV 



Meteorological Observatory of the Hatch Experi- 

 ment Station (Massachusetts Agricultural Col- 

 lege) , Amherst. 



[Latitude, 42° 23' 48.5" X. ; longitude, 72° 31' 10" W. Height of barometer above ground, 

 51 feet; above sea level, 273.5 feet. Height of wind instruments, 72 feet.] 



Annual Summary for 1906. 



Pressure {in Inches) . 



Maximum reduced to freezing, 30.G3, 

 February 11, 11 a.m. 



Minimum reduced to freezing, 28.94, Jan- 

 uary 4, 12 M. 



Maximum reduced to freezing and sea 

 level, 30.95, February 11, 11 A.M. 



Minimum reduced to freezing and sea 

 level, 29.25, January 4, 12 M. 



Mean reduced to freezing and sea level, 

 30.051. 



Annual range, 1.70. 



Air Temperature (in Degrees F.)A 

 Highest, 91.0, September 18, 3.30 p.m. 

 Lowest, — 7.5, March 24, 7 a.m. • 

 Mean, 47.3. 



Mean of means of max. and min., 47.6. 

 Mean sensible (wet bulb), 42.9. 

 Annual range, 98.5. 

 Highest mean daily, 77.8, August 23. 

 Lowest mean daily, 4.4, December 8. 

 Mean maximum, 58.3. 

 Mean minimum, 37.0. 

 Mean daily range, 21.3. 

 Greatest daily range. 47.5, March 25. 

 Least daily range, 3.0, May 28, September 



2, December 21. 



nuinidity. 

 Mean dew point, 38.6. 

 Mean force of vapor, ..383. 

 Mean relative humidity, 77.1. 



Wind. — Prevailing Direction, West, 

 Northwest. Summary {Per Cent). 

 North, northwest, 13. 

 North, 10. 

 South, 12. 

 Northwest, 11. 

 Other directions, 54. 

 Total movement, 53.273 miles. 



Greatest daily movement, 572 miles, 



February 28. 

 Least dally movement, 1 mile, February 



14, May 0. 

 Mean daily movement, 146 miles. 

 Mean hourly velocity, 6.1 miles. 

 Maximum pressure per square foot, 12.0 



pounds = 49 miles per hour, December 



1,6 p.m., N.N.W. 

 Maximum velocity for 5 minutes, 36 miles 



per hour, April 24, 2 p.m., N.N.W. ; 



December 1, 7 p.m., W.N.W, 



Precipitation (in Inches). 

 Total precipitation, rain or melted snow, 



45.45. 

 Number of days on which .01 or more rain 



or melted snow fell, 121. 

 Snow total in inches, 56i,i. 



Weather. 

 Mean cloudiness observed, 50 per cent. 

 Total cloudiness recorded by sun ther- 

 mometer, 1,794 hours = 40 per cent. 

 Number of clear days, 130. 

 Number of fair days, 140. 

 Number of cloudy days, 95. 



Bright Sunshine. 



Number of hours recorded, 2,660=60 per 

 cent. 



Dates of Frosts. 

 Last, May 20. 

 First, September 25. 



Dates of Snow. 



Last, April 23. 

 First, November 11. 

 Total days of sleighing, 57. 



Gales of 50 or More Miles per Hour. 

 None. 



Temperature in ground shelter. 



J. E. OSTRANDER, Meteorologist. 

 T. A. BARRY, Observer. 



