In Japan as a whole there are few areas to be broadcast in the morning.
There are still many towns in the country that are broadcasting to urge children
at 17:00 in the evening to back home. (also in some urban cities, but it is very rare)https://youtu.be/8yz23xrR5QE
In Yakushima it seems to call "village broadcasting(集落放送 shuuraku housou)",https://youtu.be/fjQNB93IT_U
but in Japan as a whole it is called "town broadcasting(町内放送 chounai housou)"
or "disaster prevention radio broadcasting(防災無線放送 bousai musen housou)" usual.http://www.soumu.go.jp/soutsu/kyushu/ru/prevention.html
In coastal area, also "test broadcasting(試験放送 shiken housou)" is conducted once a week
to confirm the operation of the "tsunami" warning system.
It is also functioning as a substitute for watch in areas where agriculture is popular
as "scheduled broadcasting(定時放送 teiji housou)" or "time signal(時報 jihou)",
12:00 for lunch time break and 15:00 for tea break mainly.
In areas where mountains are close to,
broadcasting is done with contents like attention to "monkeys" and "bears".
At the fishing port, it is sometimes used as a signal of the fishing start time.
In the southern areas such as Yakushima, the "typhoon" often hits directly,
so it is also used for the purpose of disaster prevention,
and on remote islands it may be broadcast whether the ferry is operated or not in the morning.
In recent years, test broadcasting of "J-Alert" and warning of "bank transfer fraud" are increasing.https://en.wikipedia.org/wiki/J-Alerthttps://en.wikipedia.org/wiki/Phone_fraudhttps://www.photolibrary.jp/mhd7/img591/450-20180423110053181017.jpg
In holiday morning extraordinary broadcast,
it is mostly whether or not to hold a local event (traditional fes and sports day).
Also to signal whether to hold a festival or not especially sports day(運動会 undou kai),
some fireworks(花火 hanabi) are launched at 6:00 or 7:00 rather than broadcasting also usual.https://youtu.be/ljl7KaqmhW4https://youtu.be/ZF1XYnz0Fxw