ABSTRACT
This chapter demonstrates seasonal distribution of suicide and its secular trends in various countries. The secular trend of the seasonal suicide distribution in these countries is almost similar to that of Japan. In Hokkaido, a trough of the monthly hours of sunshine in winter occurs in December-January, while a trough of the suicide rate appears later in January. In Eastern Tohoku, a trough of the monthly hours of sunshine and that of the monthly suicide rate in winter are both in January. The investigation of the effects of meteorological factors on suicides was approached in two ways: one is to study the direct influences of weather conditions on each suicide attempt; the other is to study the effects of meteorological factors on the seasonality of suicide deaths. The chapter discusses the effects of meteorological factors on suicidal behavior. It examines correlation between suicide deaths and hours of sunshine using annual, monthly and daily statistical data.
