Saitama Prefecture is located in the Kantō region, with its prefectural government in Saitama City. As part of the Greater Tokyo Area, it has a population of about 7.34 million, ranking 5th nationwide after Tokyo, Kanagawa, Osaka, and Aichi. Its population density is the 4th highest, trailing only Tokyo, Osaka, and Kanagawa. Despite ranking only 39th in land area, Saitama boasts the nation’s second-highest ratio of inhabitable land, reflecting its vast flatlands suitable for residence and development. Historically, the area largely corresponded to the northern and central part of Musashi Province. Today, Saitama borders all other Kantō prefectures except Kanagawa, and also connects to Nagano and Yamanashi in Chūbu. As one of only eight landlocked prefectures in Japan, it has no ports or coastal industries but is the country’s most populous inland prefecture. Proximity to Tokyo has made its southeastern sector a sprawling commuter belt, with large satellite towns. In 2020, its “daytime-nighttime population ratio” was just 87.6%, showing the heavy flow of commuters into Tokyo.
The prefecture’s name originates from Sakitama District under the ritsuryō system, recorded as “Sakitama” in Asuka-period sources. The Sakitama Kofun Park in Gyōda is regarded as the birthplace of the name. During the Meiji administrative reforms, areas like Urawa, Ōmiya, and Yono were reorganized and merged, eventually forming Saitama City in 2001. With a population of about 1.35 million, Saitama is the largest city among Japan’s inland prefectures. The prefecture is also a major land transport hub, where trunk railways from Tokyo to Hokkaidō, Tōhoku, Northern Kantō, Shin’etsu, and Hokuriku converge. Ōmiya Station in Saitama City is especially notable, serving Shinkansen and conventional lines, and housing the Railway Museum, making it a leading railway gateway in Japan. However, east–west railway links within the prefecture are limited, relying mainly on the JR Musashino Line. While expressways such as the Kan-Etsu, Tōhoku, Jōban, Metropolitan Inter-City (Ken-Ō), and Tokyo Gaikan provide strong road access, congestion and underdeveloped local road networks remain challenges.
Geographically, Saitama stretches 103 km east–west and 52 km north–south. Most of the land belongs to the Kantō Plain, with rivers covering 3.9% of the area—the highest ratio in Japan. The Tone River, Arakawa, and Iruma River form broad lowlands and terraces such as the Musashino Plateau, Kita-Musashino, and Ōmiya Plateau, while the Chichibu region in the west is mountainous. The Chichibu Basin is enclosed by the Outer Chichibu Mountains, and Mt. Kobushigatake (2,475 m) at the Nagano border is the source of the Chikuma, Arakawa, and Fuefuki rivers. The highest peak in Saitama, Mt. Sanpō (2,483 m), lies nearby. Edo-period river engineering, such as Tokugawa Ieyasu’s Tone River diversion, established the present-day river system.
The climate is of the Pacific type with strong inland traits. Winters are colder than Tokyo or Yokohama, with ice days common in Chichibu (sometimes falling below −10°C). Summers are intensely hot, with Kumagaya, Koshigaya, and Hatoyama frequently setting record highs above 40°C. Precipitation is relatively low, especially in winter. Regional variations are stark:
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Chichibu Mountains: large daily/seasonal differences, frequent snow in winter.
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Northern uplands: very hot summers, but winters less severe.
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Southern urban belt: humid summers, radiative cooling in winter mornings.
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Hilly basins (Hatoyama, etc.): extreme cold in winter nights but also Japan’s highest summer temperatures.
These conditions foster diverse agriculture, with top national yields of scallions, spinach, taro, komatsuna, and turnips in the northern plains.
Cultural and tourism resources include:
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Nagatoro Gorge, famed for its clear waters and rock terraces.
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Sōka Matsubara, part of the Oku no Hosomichi scenic sites.
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Sanbaseki Gorge (shared with Gunma), a nationally designated scenic spot.
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Kawagoe’s kura-zukuri warehouse district, an Important Preservation District, reflecting Edo-to-Meiji commercial heritage.
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Hanjūin Shōden Hall (Kumagaya), a National Treasure.
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Natural Monuments such as the Tajimagahara primrose habitat, Ushijima wisteria, and Mitake Kagami Rock.
Air Quality Index (AQI)
Administrative district
Tourist attraction
