In Japan, January is considered the coldest month of the year. That means temperatures plunging below freezing in Honshu (Japan's main island — this is where Tokyo and Kyoto are located). Or at least reaching single digits (the 30s/40s Fahrenheit).

January is officially the coldest month in Japan, marking the peak of the winter season. During this time, a high-pressure system over Siberia sends cold winds across the Sea of Japan, resulting in heavy snowfall on the western side of the country and crisp, sunny, but frigid days on the Pacific side. In Tokyo, average daytime highs hover around 10°C (50°F), while nighttime temperatures can drop to 0°C to 2°C (32°F-36°F). In northern regions like Hokkaido, the cold is far more extreme, with average temperatures in Sapporo frequently staying well below freezing throughout the month, often dipping to -8°C (18°F). This is the prime month for Japan’s famous ski resorts and winter festivals, but it requires serious layering. Even in the relatively "milder" southern islands like Kyushu, January brings a biting chill that necessitates heavy coats. For travelers, January offers the benefit of low humidity and clear views of Mt. Fuji, provided they are prepared for the peak of the Japanese winter.