Japan is currently experiencing diverse winter weather conditions across various regions as of January 2025, marked by the interplay of winter atmospheric pressure patterns and localized weather phenomena.
On January 4, Kanagawa Prefecture, particularly around Hakone, witnessed the arrival of snow due to the collision of northeastern and northwestern winds forming shear lines offshore. According to Weather News, these clouds extended from the Izu Peninsula to the western parts of Kanagawa and Yamanashi Prefectures. While the plains received rain, elevated areas received snow, emphasizing significant temperature differences depending on altitude.
Drifting snow clouds brought snowfall to the Hakone region early on January 4, leading to potential icy road conditions. Meanwhile, the rest of the Pacific side experienced clearer weather, benefiting from stable high pressure. The weather on January 4 was markedly influenced by these conditions, resulting in varied weather experiences across Japan.
Transitioning to January 5, as the winter pressure configuration softened, the Japan Meteorological Agency reported the passing of mobile high pressure, resulting in several areas from Kanto to Kansai enjoying sunny weather. Yet, western regions like Kyushu and Shikoku anticipated incoming low pressure from the west, which was expected to bring cloud cover and rain by nightfall.
The northern Japan Sea regions also faced fluctuated weather, with initial precipitation easing during the day only to return later, prompting residents to be prepared with rain gear. Despite the changes, the biting cold remained prevalent, with strong advisories issued for maintaining proper winter attire throughout the New Year holiday.
The Pacific side was chilled by radiative cooling, with warnings of potential colds, particularly as the forecast for major cities like Tokyo and Osaka indicated maximum temperatures of 13°C and 12°C, respectively. Despite mild highs, the persistent cold requires vigilance, especially as many prepare to transition back to work following the holiday break.
Health experts particularly urged residents to observe rigorous hygiene practices, like handwashing and gargling, to guard against seasonal flu and other infections. Tokyo and Nagoya were cited where preventive measures were classified at alert levels as the risk of catching colds increased.
Overall, the winter atmospheric conditions across Japan are fluctuated by distinct geographical influences and resultant weather patterns. Residents are urged to be astute about potential hazards due to icy road conditions and to diligently watch the weather reports as forecasts change from day to day. With the unpredictability of winter weather, staying warm and prepared remains imperative.