MONTHLY SUMMARY 



April 1939 



Normal 



Extremes 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.48, 1 7th 



Minimum 29.33, 2nd 



Mean semi-daily 29 925 



Range 115 



Air Temperature, in degrees F. 



Highest 82. 25th 



Lowest 24, 8th 



Mean 42.5 



Range 58 



Highest mean daily 61.5, 25th 



Lowest mean daily 31.0, 10th 



Mean maximum 5 1 .9 



Mean minimum 33.0 



Greatest daily range 41, 25th 



Least daily range 7, 18th 



Precipitation, in inches 



Precipitation 4.56 



Snow 2.00 



Max. precipitation in 24 hrs 1.23, 2nd 



Number of days with 01 or more 13 



Wind, in miles 



Total movement 4711 



Greatest daily movement 329, 13th 



Least daily movement 56. 25th 



Mean hourU velocity 6.5 



Maximum velocity 39, 14th 



Wind, direction 



Prevailing direction NW 



North, days 5 



Northeast, days 2 



East, days 1 



Southeast, days 3 



South, days 3 



Southwest, days 2 



West, days 4 



Northwest, days 10 



Weather 



Mean relative humidity-, percent 68.8 



Mean cloudiness, percent 69 



Number of clear days 10 



Number of fair days 8 



Number of cloudy days 12 



Number hours bright sunshine 189 



Percent of possible hours of bright 



sunshine 47 



Thunder and lightning 26th 



Frosts after the 15th None 



Last snow April 9 



30.48 



29.38 



29.99 



1.11 



79.4 

 22.0 



45.7 

 57.4 



3.35 

 2.17 



11 



5404 



7.5 

 31.4 



WNW 



61.6 



51.8 



11 



9 



10 



220 



54.7 



30.71, 1911 

 28.99, 1907, 1929 



1.52, 1030; .72, 1919 



88 5, 1896 



8.5, 1923 



52. 1921; 41.2, 1926 



6.89, 1929; .76, 1892 

 11, 1891; 0, 1910, 1934 



18, 1909; 3, 1892 



8208, 1908; 3853, 1917 



40, 1935, 1938 



75, 1901; 34, 1925, 1927 



19. 1911; 3, 1898, 1902 



18, 1915; 2, 1894, 1901 



22, 1901; 3, 1899, 1924 



296, 1911; 103, 1901 



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 1938. 



