Gunma Prefecture is an inland prefecture located in the northwestern part of the Kanto region of Japan. Its capital is Maebashi City. Historically known as Kōzuke no Kuni (Jōshū), Gunma has a rich history of traditional agriculture and the textile industry. In modern times, it has also developed thriving machinery and tourism industries. According to the 2020 national census, Gunma has a population of approximately 1.94 million, ranking 18th in Japan, and covers an area of 6,362.28 square kilometers, making it a medium-sized prefecture.
Geography and Cities
Gunma is located at the northern edge of the Kanto Plain. The southeastern part is flatland, while the northern and western areas are mountainous. The Tone River, the largest river system in the Kanto region, flows through the prefecture and serves as a crucial source of hydroelectric power and water supply. The Tone River's upstream dam system plays a key role in supplying water to the Tokyo metropolitan area and other parts of Kanto.
The capital, Maebashi City (population approx. 320,000), and Takasaki City (population approx. 360,000), the commercial and transportation hub, are adjacent to each other, forming the largest urban area in Northern Kanto with a combined population of about 1.26 million. Takasaki Station is especially important as a major transportation hub where the Shinkansen also stops.
Industry and Characteristics
Gunma has long been known for cultivating rice and wheat, as well as for sericulture and the textile industry. In modern times, it has expanded into machinery, food, and beverage industries. The main industries today include:
-
Agriculture: In addition to rice and wheat, livestock farming and vegetable cultivation are thriving. Local specialties include cabbage, konjac, and green onions.
-
Manufacturing: As part of the Northern Kanto Industrial Region, machinery manufacturing is well-developed. The southeastern area is particularly urbanized, with many factories and logistics centers.
-
Tourism: Famous for hot springs such as Kusatsu Onsen, along with Ikaho Onsen and Shima Onsen. The region offers a rich array of natural and historical tourist attractions.
Climate Characteristics
Due to its diverse terrain, Gunma exhibits significant regional climate variations.
Southern (Plains) Area
The southern region has a mix of Pacific and inland climates, characterized by hot summers and dry, sunny winters.
-
Summer: The Foehn effect and urban heat island phenomenon make cities like Takasaki, Maebashi, Isesaki, and Tatebayashi some of the hottest places in Japan, occasionally reaching close to 40°C (104°F). Tatebayashi often ranks among Japan's top cities for the number of extremely hot days.
-
Winter: Mostly sunny with little snowfall. However, strong seasonal winds such as the "Akagi Oroshi" blowing from Mount Akagi lower the perceived temperature. Although minimum temperatures are relatively high for the Kanto region, the strong winds are a distinctive feature.
Northern and Western (Mountainous) Areas
The high-altitude regions experience a mix of Japan Sea and Central Highland climates.
-
Summer: Cool and pleasant. Areas like Kusatsu Onsen and Tsumagoi Village, located over 1,000 meters above sea level, rarely experience midsummer heat, making them popular summer resorts.
-
Winter: Heavy snowfall occurs due to snow clouds from the Japan Sea. Some areas are designated heavy snowfall zones. Notably, Katashina Village is the only special heavy snowfall area in the Kanto region. In Minakami Town, snow accumulation can exceed 3 meters. In higher elevations, temperatures can drop below −20°C (−4°F).
Annual Temperature and Precipitation
-
Average Annual Temperature: Around 15.5°C in Isesaki (south), 15.0°C in Maebashi, 12.1°C in Numata (north), and 7.4°C in the coldest area, Tsumagoi Village.
-
Precipitation: Approximately 1,200mm in the south, while the north ranges from 1,100mm to 1,700mm depending on the area.
Gunma’s Appeal
Gunma offers a unique blend of rich natural environments and developed industries. Its famous hot spring resorts, led by Kusatsu Onsen, attract visitors nationwide. With stunning natural landscapes, historic towns, and abundant local produce, Gunma captivates all who visit.
The southern part is highly convenient as part of the Tokyo metropolitan area, while the north and west provide breathtaking natural scenery and a vivid sense of the changing seasons. Gunma is also known as "Thunder Alley" (Kaminari Ginza) due to frequent lightning, allowing visitors to experience the raw power of nature.
One of Gunma’s greatest charms is its diversity in climate and landscape, offering vastly different faces across its regions, all within the same prefecture.