Overview
The Kiso Valley, traversed by the historic Nakasendo Trail, experiences a continental climate characterized by warm, humid summers and cold, sometimes snowy winters. Many prefer hiking in the mild Spring and Autumn seasons, though Summer and early Winter is also an option.
Temperatures
- Spring (March to May): Temperatures gradually rise, with average highs ranging from 10°C to 20°C (50°F to 68°F) and lows from 0°C to 10°C (32°F to 50°F). This season is renowned for cherry blossoms and other floral displays.
- Summer (June to August): The region experiences warm and humid conditions, with average highs between 25°C and 30°C (77°F to 86°F) and lows from 15°C to 20°C (59°F to 68°F). While June marks the rainy season, July and August are typically hotter with higher humidity.
- Autumn (September to November): Temperatures decline, with average highs ranging from 20°C to 10°C (68°F to 50°F) and lows from 10°C to 0°C (50°F to 32°F). The season offers vibrant autumn foliage, making it a favored time for hikers.
- Winter (December to February): The valley experiences cold conditions, with average highs between 5°C and 0°C (41°F to 32°F) and lows from -5°C to -10°C (23°F to 14°F). Snowfall is common, especially in northern areas like Kiso-Fukushima and Narai, adding a picturesque quality to the landscape.
Rainfall
The region receives significant rainfall during the summer months, particularly in June and July, due to the East Asian monsoon. Annual precipitation averages between 1,200 mm to 1,500 mm (47 to 59 inches), with the heaviest rainfall occurring during the rainy season known as "Baiu."
