Monthly Summary 



April. 1937 



Normal 



Extremes 



Barometer 



(Readings reduced to sea level) 



Maximum 30.53, 4th 



Minimum 29.49, 15th 



Mean semi-daily 3Q.021 



Range 1.04 



Air Temperature 



Highest 71, uth 



j-iowest 24, 1st 



Mean 45 



Monthly range 47 



Highest mean daily 56, 14th, i9th 



Lowest mean daily 34.5, 2nd 



Mean maximum 55.4 



Mean minimum 34.5 



Greatest daily range 37, 13th 



Least daily range 6, 22nd 



Precipitation 



Precipitation. In inches 4.03 



Snow, in inches 0.50 



Maximum precipitation in 24 hrs. 



1.10 22nd 

 Number of days on which .01 or more 



inches of precipitation fell.... 12 



Wind (miles) 



Total movement 4,888 



Greatest daily movement 300, 23rd 



Least daily movement 70, 2nd 



Mean hourly velocity 6.8 



Maximum velocity, 5 min., .... 26, 20th 



Wind (direction) 



Prevailing direction n 



North, days 7 



Northeast, days 2 



East, days 2 



Southeast, days 6 



South, days 3 



Southwest, days 



West, days 3 



Northwest, days 7 



Weather 



Mean relative humidity, per cent. . 61.6 



Mean cloudiness, per cent 57 



Number of clear days 14 



Number of fair days 4 



Number of cloudy days 12 



Number of hours bright sunshine . . 208 

 Percent of possible hours of bright 



sunshine 51.7 



Thunder and lightning 15th, 18th, 28th 

 Frosts after 15th 21st, 25th, 26th 



30.48 



29.41 



29.99 



1.08 



79.5 

 21.6 

 45.8 

 57.8 



3.27 

 2.32 



11 

 5,436 



7.5 

 29 



82.0 



49.2 



11 



10 



9 



221 



55 



30.71, 1911 

 28.99, 1907, 1929 



1.52, 1930; 0.72, 1919 



88.5, 1896 

 8.5, 1923 



6.89, 1929; 0.76, 1892 

 11, 1891; 0, 1910 



18, 1909; 3, 1892 

 8,208, 1908; 3,853, 1917 



40, 1935 



75, 1901; 34, 1925, 1927 



19, 19)1; 3, 1898, 1902 



18, 1915; 2, 1894, 1901 



22, 1901; 3, 1899, 1924 



296, 1911; 103, 1901 



Note— The first cohmm in the above suinraary gives observations made dnrinir the 

 month. The second column (rives the averaires based on observations made from 18"9 

 to 1928. except that humidity records are based on observations made from 192'.) to I'XMi 

 The third column gives extremes observed from 1889 to 193(i. 



