MONTHLY SUMMARY 



APRIL, 1951 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.395, 22nd 



Minimum 29.230, 15th 



Mean semi-daily 29.899 



Range 1. 165 



Air Temperalure, in Degrees F. 



Highest 71, 29th 



Lowest 30, 5th, 24th 



Mean 48.4 



Range 41 



Highest mean daily 59, 29th 



Lowest mean daily 39.5, 5th 



Mean maximum 59.1 



Mean minimum ■. 37.9 



Greatest daily range 34, 24th 



Least daily range 7, 2nd 



Degree-days of heating load for month. . 500 

 Degree-days cumulative for season 582 1 



Precipitation, in inches 



Precipitation 3.63 



Snow 



Maximum precip. in 24 hrs 1.64, 3rd 



Number of days with .01 or more 14 



Wind, in miles 



Total movement 4422 



Greatest daily movement 293, 23rd 



Least daily movement 48, 1st 



Mean hourly velocity 6.1 



Maximum velocity 40, 15th 



Wind, direction 



Prevailing direction W 



North, days 5 



Northeast, days 2 



East, days 



Southeast, days 3 



South, days 4 



Southwest, days 5 



West, days 4 



Northwest, days 7 



Weather 



Mean relative humidity, percent 72.6 



Mean cloudiness, percent 50.0 



Number of clear days 7 



Number of fair days 10 



Number of cloudy days 13 



Number of hours bright sunshine 169.7 



Percent of possible hours of 



bright sunshine 42.3 



Thunder and Lightning 10th 



Last Snow 



First Frost 



Normal 



30.48 



29.38 



29.99 



1.11 



79.4 

 22.0 

 45.7 

 57.4 



56.8 

 34.8 



579 

 6455 



3.35 

 2.17 



11 



5404 



7.5 

 31.4 



WNW 



61.6 



51.8 



11 



9 



10 



220 



54.7 



Apr. 15 



Extremes 



30.71, 1911 

 28.98, 1943 



1.52, 1930; 0.65, 1950 



90, 1941 



8.5, 1923 

 52, 1921; 41, 1943 



6.89, 1929; .55, 1941 

 11, 1891; 0, 1910, 1934 



18, 1909; 3,1892 



8208, 1908; 3853, 1917 



40, 1935, 1938, 1940, 1945 



75, 1901; 34, 1925, 1927 



23, 1941; 1, 1949 



18, 1915; 2, 1894, 1901 



22, 1901; 1, 1941 



329, 1941; 103, 1901 



Mar. 14, 1910; May 11, 1907.'45 



Note — The first column in the above summarj' gives observations made during the month. 

 The second column gives the averages based on observations made from 1889 to 1938, 

 except that humidity lecords are based on observations made from 1929 to 1938, The 

 third column gives extremes observed from 1889 to 1950. 



