MONTHLY SUMMARY 



May 1941 



Normal 



Extremes 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.18, 20th, 21st 



Minimum 29.40, 17th 



Mean semi-daily 29.905 



Range 0.78 



Air Temperature, in degrees F. 



Highest 89, 22nd 



Lowest 30, 4th 



Mean 57.9 



Range 59 



Highest mean daily 73, 23rd 



Lowest mean daily 44, 2nd 



Mean maximum 72.5 



Mean minimum 43.3 



Greatest daily range 44, 6th 



Least daily range 14, 1st, 9th 



Precipitation, in inches 



Precipitation 2.87 



Maximum precipitation in 24 hrs. 



1.55 9th, 10th 



Number of days with .01 or more 8 



Wind, in miles 



Total movement 4250 



Greatest daily movement 359 18th 



Least daily movement 31, 31st 



Mean hourly velocity 5.7 



Maximum velocity 28, 25th 



Wind, direction 



Prevailing direction NW 



North, days 8 



Northeast, days 1 



East, days 



Southeast, days 



South, days 6 



Southwest, days 5 



West, days 1 



Northwest, days 10 



Weather 



Mean relative humidity, percent 63.9 



Mean cloudiness, percent 46 



Number of clear days 20 



Number of fair days 9 



Number of cloudy days 2 



Number hours bright sunshine 338 



Percent of possible hours of bright 



sunshine 74 . 6 



Thunder and lightning 23rd 



Last frost May 13th 



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 



May 14 



30.62, 1936 

 29.10, 1938 



94.5, 1896, 1911 

 24.0, 1900 



7.44, 1931; .48,1903 



20, 1901; 5, 1903 

 5946, 1907; 2180, 1894 



45, 1935 



70, 1901, 1902; 30, 1923 



20, 1923; 0, 1927 



17,1907, 1926; 5, 1923 



20, 1927; 3, 1903, 1922 



334, 1922; 137, 1927 



June 8, 1932; 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 1940. 



