In days gone by, "the Kibi no Nakayama mountains" located in the western part of Okayama City and spreading out like a carp swimming in water was so well-known that they were written in a poem in Kokin Wakashu, or "A Collection of Ancient and Modern Japanese Poetry", collected by Imperial command in the early 10th century. There are a lot of tumuli including large-scale keyhole-shaped ones here and there on the mountains.

In ancient times, the area mainly consisting of all of Okayama Prefecture and the eastern part of Hiroshima Prefecture was named Kibi Province and formed a huge cultural area as a strategic point for transportation between the Kinai Region composed of parts of Nara, Osaka and Kyoto prefectures, and Kyushu Region located near the Asian Continent.

Taking advantages of its warm and mild climate in addition to few natural disasters such as typhoons and volcanic eruptions, rice farming was developed in the area. Located on the northeastern edge of Kurashiki City, Tatetsuki Grave Mound, where the inside of a wooden coffin was blanketed with thirty kilograms of vermillion and an iron sword and a lot of gems were excavated, was constructed nearly 1,800 years ago. According to Okayama Prefectural Ancient Kibi Cultural Properties Center, it is considered that the person buried in the grave may be the paramount chief who unified a lot of tribes into Kibi Province. However, the numerous tumulus and remains in the area cannot specify the origin of Kibi Province now.

Judging from the fact that a lot of tumuli lie in Okayama Prefecture, the province had almost equal power to the Yamato line of emperors, to struggle for supremacy. And later it was divided by the central government into three, Bizen, Bitchu and Bingo: the nearest to Kyoto, the eastern part, is Bizen, and Bingo is the present eastern part of Hiroshima Prefecture as well as the present western part of Okayama Prefecture. And then Bizen was divided from north to south, Mimasaka and Bizen. Today, Bizen, Bitchu and Bingo are used as a prefix to names of places, stations and others like Bizen-Osafune and Bitchu-Takahashi Station.

Provincial cities and towns in Japan, such as those in Okayama Prefecture, are packed with Japanese traditions handed down for generations. Moreover, refined rusticity remain everywhere in the countrysides, such as Fukiya and islands in the Seto Inland Sea National Park, along with natural beauty even now.

Okayama Prefecture except its northern part has a mild and comfortable climate all year around with little rainfall. It is sandwiched between Chugoku Mountains on the north side and Shikoku Mountains on the island of Shikoku beyond the Seto Inland Sea. These mountains protect this region from chilling winds and typhoons.

Setouchi region along the Seto Inland Sea has relatively little rainfall all year round. Okayama Prefecture is well known as "Hare no Kuni", or "the land of fair weather", due to its mild temperature and low rainfall. According to the Japan Meteorological Agency, the average annual temperature in Okayama City is 16.2 degrees Celsius while that in Tokyo is 15.4 degrees Celsius. The total number of days with precipitation less than 1 mm in Okayama City is 276.8 days , first among the main observation sites of 47 prefectures, while that in Tokyo is 263.6 days, The average annual rainfall in Okayama City is 1,105.9 mm, third lowest amount of rainfall, while that in Tokyo is 1,528.8 mm, based on the data from 1981 to 2010.

Okayama Prefecture is blessed with favorable conditions such as a good environment for taking a walk and cycling.

Okayama Prefecture has few natural disasters such as typhoons, volcanic eruptions, earthquakes and tsunamis. Because Shikoku Mountains on the island of Shikoku beyond the Seto Inland Sea block typhoons coming mainly from July to October, Okayama Prefecture receives little damage from typhoons. Considering that there is no active volcano in and close to Okayama Prefecture, there would be no possibility of being hit by volcanic disasters. According to Okayama Local Meteorological Office, no earthquake with seismic intensity 6 or over on ten-step scale which indicates the degree of shaking between 0 and 7 at an observation point on the ground surface, on which it is difficult to remain standing, has been observed in Okayama Prefecture after the first monthly report on earthquakes in Japan was issued in 1926. There is very low possibility that a huge tsunami occurs because Okayama Prefecture lies on a calm inland sea. According to Okayama Prefecture, the highest tsunami waves triggered by an earthquake and reaching the coastline of Okayama Prefecture on record are 21 cm high, caused by the magnitude 9.5 Chile earthquake in 1960. Off the record, the coast was hit by tsunami less than one meter high caused by the earthquake of magnitude 8.0, which gave extensive damage to areas along the Pacific Ocean in western Japan, in 1946.

In addition to the above natural disasters, no nuclear power plant is located in Okayama Prefecture. It can be considered that Okayama Prefecture is one of the safest prefectures in Japan.