MONTHLY SUMMARY 



May 1940 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.27, 30th 



Minimum 29.49, Src' 



Mean semi-daily 29.913 



Range 0.78 



Air Temperature, in degrees F. 



Highest 82,15th 



Lowest 33, 13th 



Mean 57.2 



Range 49 



Highest mean daily 66.5, 20th 



Lowest mean daily 50.5, 10th 



Mean maximum 67.7 



Mean minimum 46.7 



Greatest daily range 42, 11th 



Least daily range 5, 4th, 23rd 



Precipitation, in inches 



Precipitation 5.67 



Maximum precipitation in 24 hrs. 2,58, 31st 



Number of days with .01 or more 12 



Wind, in miles 



Total movement 4041 



Greatest daily movement 314, 7th 



Least daily movement 38, 14th 



Mean hourly velocity 5.4 



Maximum velocity 40, 7th 



Wind, direction 



Prevailing direction EFE 



North, days 4 



Northeast, days 4 



East, days 3 



Southeast, days 4 



South, days 7 



Southwest, days 3 



West, days 



Northwest, days 6 



Weather 



Mean relative humidity, percent 70.3 



Mean cloudiness, percent 70 



Number of clear days 8 



Number of fair days 8 



Number of cloudy days 15 



Number hours bright sunshine 182 



Percent of possible hours of bright 



sunshine 40 



Thunder and lightning 3rd 



Last frost May 13 



Normal 



Extremes 



30.39 



29.51 



29.96 



0.88 



86.1 

 31.2 

 57.1 

 54.9 



3.60 



12 



4504 



6.1 



28.8 



W 



60.7 



52.1 



11 



11 



9 



252 



55.6 



Mav 1- 



30.62, 1936 

 29.10, 1938 



94.5, 1896, 1911 

 24.0, 1900 



7.44, 1931; .48, 1903 



20, 1901;5, 19C3 



5946, 1907; 2180, 1894 



45, 1935 



70, 1901; 30, 1923 



20, 1923; 0, 1927 



17, 1907, 1926; 5, 1923 



20, 1927; 3, 1903, 1922 



334, 1922; 137, 1927 



June 8, 1632; Apr. 23,1904 



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. 



