1916] METEOROLOGY. 507 



pis. 2, figs. 6). — These numbers contain, respectively, brief summaries and 

 detailed tabular statements of climatological data for each State for March and 

 April, 1916. 



Climatology of State College, Pennsylvania.— II, Precipitation (rain and 

 snow), W. Fkeak (Pennsylvanm Sta. Rpt. 19V,, pp. 235-3.^7 ) .—This is an 

 elaborate discussion of precipitation at State College, Pa., based upon observa- 

 tions from 1880-1913, inclusive. It supplements a similar discussion of the 

 temperature of this place published in a previous report (E. S. R., 34, p. 115). 



The records show that the locality belongs to the common class as regards 

 hours of greatest rainfall frequency, namely, that in which rains are least 

 frequent in the hours immediately preceding noon. "The larger precipitation 

 in the afternoon as compared with the morning division of the late spring and 

 summer days is due both to the greater frequency of the rainfall at that time 

 of day, and also to the greater average quantity of the afternoon as compared 

 with the morning rains. In like manner, the night time precipitation is on the 

 average greater than that at other times of day during the remainder of the 

 year, and for the same reason— that the night rains are then the more frequent 

 and more copious." The summer daytime precipitation is about one-half 

 greater than that occurring by night w-hen the total precipitation through the 

 period is considered. 



" Considering the number of rainy days in the year, as indicated by the 

 occurrence of measurable precipitation, 1886 with 99 days had the least, and 

 1911 with 157 days, the most. The average for all years was 130.3 days, or 

 about 4.3 days out of twelve." 



The largest precipitation occurred in the summer months ; the smallest in 

 the winter. The data give no support to the popular idea of the relation of 

 rainstorms to holidays or to equinoxes. 



The average annual rainfall for the period was 39.762 in., and this was dis- 

 tributed by seasons approximately as follows : Winter 8.82 in., spring 10.52 in., 

 summer 11.76 in., and autumn 8.38 in. There was no regularity of annual pre- 

 cipitation. " Of the 30 years for which the records are complete, the annual 

 total falls below the average in 13 cases, and exceeds it in 17 cases. The 

 extreme range is from 30.845 in. in 1887 to 46.545 in. in 1891, a range of 15.7 in., 

 which is more than half of the minimum. The mean between the extremes is 

 38.695 in., or 1.067 in. below the average." For one-half of the years the annual 

 average was above 40 in. 



As regards unsettled weather the winter and spring months showed the 

 greatest frequency and the summer months least. Dry spells, that is, periods of 

 14 days or more in which less than 0.1 in. of rain fell, were very irregularly 

 distributed among the months, but the last four months of the year showed 

 them in the greater frequency. "That is, the dry spells are most frequent at 

 the season when the number of crops that can be directly affected is least. May 

 stands next in the order of frequency, and represents a critical period in the 

 life of the majority of farm and garden crops, but June had but one dry spell 

 in the thirty years for which the detailed records are at hand ; so that it tends, 

 on the average through many years, to compensate for the May fickleness of 

 water supply." 



The average seasonal snowfall for the period was 47.18 in. It ranged from 

 18.01 in. in the winter of 1888-89 to 83.14 in. in the winter of 1907-08. The 

 greatest snowfall of a single month was that of February, 1908, when 41.8 in. 

 fell. The ratio of rainfall to snowfall of the winter season was as 74 of the 

 former to 26 of the latter. The greatest snowfall in any one day was 17.5 in., 

 March 5, 1902. 



