Abstract
In Hidaka district, the author investigated the relationships between the distribution of rice yields per tan and physical conditions. The results obtained are as follows ;
(1) The regional distribution of rice yields per tan in this district is related to the distribution of accumulated air temperatures which is affected by the frequency of the sea fog.
(2) The rice yields per tan in the eastern part are lower than in the middle and western parts. Within four kilometers from the coast, the yields are lower than in the middle- and upper-stream areas.
