Abstract
Seasonal variation of conception rate and suicide death ratio is studied on the data of UN and WHO. Although the peak of conception curve coincides with that of suicide death ratio in most European countries and in Japan, the fact is not universal. The peak of the seasonal variation of conception rate moves from midsummer in subfrigid climate countries to winter in subtropical countries. Such geographic alteration does not seem to be found by suicide death ratio, though the data are not enough to conclude it, and the peak of the curve seems to be always in spring.
The peak of the seasonal conception curve is usually found in the season when the monthly average temperature is about 20°C. However, in most European countries and in Japan the curve rises only in spring. By Japanese data, the peak of the seasonal variation of suicide deaths moves by age group. The younger the subject, the earlier in spring the peak appears.
