158 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1957 



RAINFALL 



During the dry season (January through April) of the calendar 

 year 1956, rains of 0.01 inch or more fell during 55 days (279 hours) 

 and amounted to 12.53 inches, as compared to 10.78 inches during 1955. 

 During the wet season of 1956 (May through December), rains of 

 0.01 inch or more fell on 215 days (989 hours) and amounted to 101.52 

 inches, as compared to 103.62 inches during 1955. Total rainfall for 

 the year was 114.05 inches. During 32 years of record the wettest 

 year was 1935, with 143.42 inches, and the driest year was 1930, with 

 only 76.57 inches. February was the driest month of 1956 (2.11 

 inches) and July the wettest (19.5 inches). The maximum records 

 for short periods were : 5 minutes 1.30 inches ; 10 minutes 1.65 inches ; 

 1 hour 4.11 inches; 2 hours 4.81 inches; 24 hours 10.48 inches. 



Table 1. — Annual rainfall, Barro Colorado Island, C. Z. 



Year 



Total 

 inches 



Station 

 average 



1925 --- 104.37 



1926 118.22 



1927.. 116.36 



1928 -- 101.52 



1929 87.84 



1930... -- 76.57 



1931 --- 123.30 



1932 113.52 



1933 101.73 



1934 122.42 



1935 143.42 



1936 93.88 



1937 124. 13 



1938 117.09 



1939 115.47 



1940 86.51 



113.56 

 114.68 

 111.35 



106. 56 

 101. 51 



104. 69 



105. 76 

 105. 32 



107. 04 

 110. 35 



108. 98 

 110. 12 

 110. 62 

 110.94 



109. 43 



Total 



Year inches 



1941 91.82 



1942 111. 10 



1943 120.29 



1944 111.96 



1945 120.42 



1946 87.38 



1947 77.92 



1948 83. 16 



1949 114.86 



1950 114.51 



1951 112.72 



1952 97.68 



1953 104.97 



1954 105.68 



1955 114.42 



1956 114.05 



Station 

 average 



108. 41 



108. 55 



109. 20 

 109. 30 

 109. 84 

 108. 81 

 107. 49 

 106. 43 



106. 76 



107. 07 

 107. 28 

 106. 94 

 106. 87 



106. 82 



107. 09 

 107. 30 



Table 2. — Com-parison of 1955 and 1956 rainfall, Barro Colorado Island (inches) 



