METEOROLOGICAL OBSERVATORY 



OF THE 



Hatch Expcrifflent Station 



MASSACHUSETTS AGRICULTURAL COLLEGE, 



.A^JVEHEI^ST. 



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



Height of instruments above ground, 51 Jl. Above sea level, 260 ft. 



BULLETIN No- 30. 



JUNE, 1891 



MONTHLY SUMMARY. 



Preamtre. In Inches. 

 Actual maximum reading, . 29.94, 6th, 10 a 

 Actual minimum rcaillng, . . -29.41, '28th, 2 p 



Mean rciluceil to sea level 29.919 



Monthly range, 53 



*Air Temperature. In Degrees Fahr, 



Highest, 91.5; 94 



Lowest, 40. ; 34 



Mean, 66.6; 6.5.2 



Monthly Range, 51 .5 ; 60 



Highest mean daily, 79.6; 76. 



Lowest mean daily, 52. ; 51. 



Mean maximum, 76. ; 78.5 



Mean minimum 57. ; 51.0 



Mean dally range, 19. ; 26.6 



Greatest daily range, 34.5; 44. 



Least daily range 3 ; 10. 



Humidity. 



Mean dew point, 57. 



Mean force of vapor, 7811 



Mean relative humitllty, Co. 3 



Wind. 



Prevailing Directions. 



North, 16 per cent. 



South, 15 " 



North North East, 13 " 



South West, 9 " 



Other directions, 47 " 



Total movement, 3713 m. 



Greatest daily movement, .... 409 m., 27th 



Least daily movement 32 m., 7t)i 



Mean dally movement, 123.8 m. 



Mean hourly velocity, 5.2 m. 



Maximum pressure per square foot,10ilbs.= 

 46 m. per hour, 24th, at 11.30 A. 



* Precipitation. In inches. 

 Total precipitation, 4.36; 4.75 



Weather. 



Mean cloudiness observed, ... 47 per cent. 



Number of clear days, 14 



Numl)er of cloudy days 8 



Number of fair days, 8 



Total cloudiness recorded by the Sun Ther- 

 mometer, 208 hours or 46 per cent. 

 Number of days on which .01 inch or more 

 rain fell, 9 



Bright Sunshine. 



Number of Hours recorded, 248 



Rain, 2d, .3d, 4th, 13th, 16th, 17th, 18th, 19th, 



20th, 2l8t,22d, 26th. 

 Thunder and TAghtning, 2i\, .3d, 16th, 26th 

 Mean Osone, 56 per cent. 



Ilaloa. 



Solar 5th, 6th, 7th. 



Lunar corona 12th. 



Galea, of 40or more miles per hour, 46,N.24th ; 

 41, N.N.E. 27th. 



*The first figures denote readings at top of tower, the second at base. 



