MONTHLY SUMMARY 



August 1940 



Normal 



Extremes 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.45, 1 Itli 



Minimum 29.60, 19th 



Mean semi-daily 30.114 



Range 0.85 



Air Temperature, in degrees F. 



Highest 89, 10th 



Lowest 34. 25th 



Mean 66.9 



Range 55 



Highest mean daily 77.5, 6th 



Lowest mean daily 51.5, 24th 



Mean ma.ximum 79.6 



Mean minimum 54.2 



Greatest daily range 36, 25th 



Least daily range 13, 18tli 



Precipitation, in inches 



Precipitation 1.56 



Maximum precipitation in 24 hrs. 0.60, 19th 



Number of days with .01 or more 8 



Wind, in miles 



Total movement 3219 



Greatest daily movement 182, I'Otl; 



Least daily movement 45, 2Sth 



Mean hourly velocity 4.3 



Maximum velocity 22, 20th 



Wind, direction 



Prevailing direction ^' 



North, days 5 



Northeast, days 



East, days 



Southeast, days 8 



South, days 9 



Southwest, days 



West, days 



Northwest, days 3 



Weather 



Mean relative humidity, percent 72.3 



Mean cloudiness, percent 45 



Number of clear days 13 



Number of fair days 10 



Number of cloudy days 



Number hours bright sunshine 163 



Percent of possible hours of bright 



sunshine 61.3 



Thunder and lightning 6th, 13th, 23rd 



Fiist Frost 



30.32 



29.61 



30.00 



0.71 



91.6 

 43.4 

 68.6 

 48.1 



4.08 



11 



3127 



4.2 

 22.7 



SW 



70.2 



49.7 



9 



13 



9 



237 



55.2 



Sept. 21 



30.50, 1934 

 28.87. 1930 



100, 1918 

 37, 1894, 1908 



8.40, 1928; .31, 1894 



16, 1892,1933; 4, 1899 



4,271, 1910; 1,920, 1894 



35, 1915 



67, 1901; 27, 1923 



21, 1939; 0,1915, 1929 



25, 1912; 3, 1939 



18, 1901, '28; 2, '10, '23 



317, 1921; 152, 1915,1929 



Aug. 22,'94,'95; Oct 13, '09 



Note — The first column in the above summary gives observations made during the 

 month. The second column gives the averages based on observations made from 

 1889 to 1938, except that humidity records are based on observations made from 

 1929 to 1938. The third column gives extremes observed from 1889 to 1939. 



