MONTHLY SUMMARY 



MAY, 1951 



Barometer, in inches 



(Readings reduced to sea level) 



Maximum 30.487 



Minimum 29.436 



Mean semi-daily 29.890 



Range 1.051 



Air Temperalure, in Degrees F. 



Highest 87, 16th 



Lowest 31, 14th 



Mean 58.9 



Range 56 



Highest mean daily Ti, 22nd 



Lowest mean daily 42.5, 11th 



Mean maximum 71.7 



Mean minimum 46.0 



Greatest daily range 43, 14th, 19th 



Least daily range . . .-. 6, 24th 



Degree-days of heating load for month. .211 

 Degree-days cumulative for season 6032 



Precipitation, in incties 



Precipitation 2.96 



Snow 



Maximum precip. in 24 hrs 0.87, 1 1th 



Number of days with .01 or more 9 



Wind, in miles 



Total movement 3256 



Greatest daily movement 228, 24th 



Least daily movement 41, 1st 



Mean hourly velocity 4.4 



Maximum velocity 40, 2nd 



Wind, direction 



Prevailing direction NW 



North, days 10 



Northeast, days 2 



East, days 2 



Southeast, days 1 



South, days 4 



Southwest, days 5 



West, days 2 



Northwest, days 5 



Weather 



Mean relative humidity, percent 72.2 



Mean cloudiness, percent 37.8 



Number of clear days 9 



Number of fair days 12 



Number of cloudy days 10 



Number of hours bright sunshine 211.5 



Percent of possible hours of 



bright sunshine 46.8 



Thunder and Lightning 9th 



Last Frost 14th 



Normal 



30.39 



29.51 



29.96 



0.88 



86.1 

 31.2 

 57.1 

 54.9 



245 

 6700 



3.60 

 12 



4504 



6.1 



28.8 



W 



60.7 



52.1 



11 



11 



9 



■252 



55.6 



Extremes 



30.62, 1936 

 29.10, 1938 



94.5, 1896, 1911 

 24.0, 1900 



7.44, 1931; .48, 1903 

 20, 1901, 1945; 5, 1903 



5946, 1907; 2180, 1894 

 48, 1950 



72, 1948; 30, 1923 



21, 1944; 0, 1927 



18, 1949; 5, 1923 



20, 1927; 2, 1941 



350, 1944; 137, 1927 



Note — The first column in the above summary gives observation^ 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. 



