Monthly Summary 



May, 1930 



Normal 



Extremes 



Barometer 



(Readings reduced to sea level) 



Maximum 30.34, 11th, 12th 



Minimum 29.57, 2nd 



Mean semi-daily 29.944 



Range 0.77 



Air Tomperalure 



Highest 92,7th 



Lowest 35, 31st 



Mean 59.1 



Monthly range * 57 



Highest mean daily 75.5, 7th 



Lowest mean daily. .48.0,15,26, 27th, 31st 



Mean maximum 71.1 



Mean minimum 46.9 



Greatest daily range 38.0, 1st 



Least daily range 6.0, 15th 



Precipitation 



Precipitation. In inches 3.34 



Snow, in inches 



Maximum precipitation in 24 hrs. 1.0, 



25th, 26th. 

 Number of days on which .01 or 



more inches of rain fell 14 



Wind (miles) 



Total movement 4,593 



Greatest daily movement 348, 3rd 



Least daily movement 57,22nd 



Mean hourly velocity 6.2 



Maximum velocity for 5 min 32, 4th 



(corrected to conform to 3 cup anemometer) 

 Wind (direction) 



Prevailing direction sw 



North, days 2 



Northeast, days 



East, days 3 



Southeast, days 5 



South, days 3 



Southwest, days 7 



West, days 7 



Northwest, days 4 



Weather 



Mean relative humidity, per cent. . 60.8 



Mean cloudiness, per cent 60 



Number of clear days 17 



Number of fair days . . . , 7 



Number of cloudy days 7 



Number of hours bright sunshine 285.8 

 Percent of possible hours of bright 



sunshine 63.0 



Thunder and lightning 



Frosts 31st 



Last frost 



30.38 

 29.51 

 29.95 



85.5 

 30.8 

 56.8 

 54.6 



3.63 



70.7 

 51.5 

 10 

 11 

 10 

 250.1 



55.2 



12th 



30.55, 1895 

 29.16, 1893 



1.16, 1893; 0.60, 1899 



94.5, 1911 

 24.0, 1900 



6.91, 1901 ; 0.48, 1903 



83.9, 1927; 59.3, 1891 



70, 1901 ; 30, 1923 



20, 1923; 0, 1927 



17, 1907, 1926; 5, 1923 



20, 1927; 3, 1903, 1922 



334, 1922 ; 137, 1927 



J'e 3, 1908; Apr. 23, 1904 



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

 month. The second and third columns give the averages and extremes observed from i8Sq 

 to 1929. 



