Public health is the science of protecting and improving the health of families and communities through promotion of healthy lifestyles, research for disease and injury prevention and detection and control of infectious diseases.
In the spring, southern and western Japan can be quite warm and sunny, from 59 to 77 degrees. Northern Japan ranges from 50 to 68 degrees. Snow remains on the hills into April or May in northern areas. And like Spring in much of the U.S., weather can range significantly from mild, to warm, to cold, on a daily basis.
The remainder of January is a good time for visiting Japan, as the weather is usually sunny and dry and sightseeing spots are not crowded. Only in northern Japan and along the Sea of Japan coast, there is lots of snowfall, and conditions are good for winter sports. The downside of a visit in winter are the relatively short days (sunset is around 5pm in Tokyo) and the vegetation's barren state.