MONTHLY SUMMARY 



JULY 1951 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.119, 18th 



Minimum 29.436, 5th 



Mean s^mi-daily 29.962 



Rang 0.683 



Air Temperature, in Degrees F. 



Highest 9L 16th, 26th 



Lowest 48, 7th 



Mean 72.3 



Range 43 



Highest mean daily 78, 30th, 31st 



Lowest mean daily 65, 21st 



Mean maximum 83.5 



Mean minimum 61.0 



Greatest daily range 41, 7th 



Least daily range 10, 28th 



Degree-days of heating load for month . . — 

 Degree-days cumulative for season — 



Precipitation, in inches 



Precipitation 4.16 



Snow — 



Maximum precip. in 24 hrs 1.94, 12th 



Number of days with .01 or more 8 



Wind, in miles 



Total movement 2609 



Greatest daily movement 157, 6th 



Least daily movement 38. 12th 



Mean hourly velocity 3.5 



Maximum velocity 22, 6th, 20th 



Wind, direction 



Prevailing direction SW 



North, days 4 



Northeast, days 



East, days 



Southeast, days 4 



South, days 8 



Southwest, days 3 



West, days 8 



Northwest, days 4 



Weather 



Mean relative humidity, percent 77.1 



Mean cloudiness, percent 60.3 



Number of clear days 8 



Number of fair days 17 



Number of cloudy days 6 



Number of hours bright sunshine. . . .236.8 

 Percent of possible hours of 



bright sunshine 51.1 



Thunder and lightning .... 10th, 16th, 19th 



Normal 



30.27 



29.59 



29.96 



0.68 



93.9 

 46.4 

 70.8 

 47.7 



4.10 

 11 



3422 



4.6 



28.7 



SW 



68.4 

 50.9 

 10 

 14 



7 



268 



58 



Extremes 



30.50, 1892 

 29.27, 1932 



0.97, 1892; 0.47, 1938 



104, 1911 



40, 1890, 1898 



66.3, 1891; 76.0, 1949 



14.51, 1897; 0.70, 1929 

 20, 1915; 4, 1924 



5097, 1909; 1109, 1894 

 44, 1936 



70, 1943; 31, 1924 



22, 1923; 0, 1915 



24, 1909, 1921; 4, 1946 



18, 1889; 0. 1910 



371, 1910; 180, 1931 



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 lecords are based on observations made from 1929 to 1938. The 

 third column gives extremes observed from 1889 to 1950. 



