Iiyama Weather & Climate: Best Time to Visit
Iiyama, Nagano Prefecture, Japan, sees big temperature differences between seasons, with August peaking at 29°C (84°F) and January dropping to 3°C (37°F).
Rain/snowfall is high, totalling around 2163 mm (85 in) per year. July is the wettest month and April the driest. The city also experiences a distinct rainy season from June to February. May is the sunniest month, averaging 6.6 hours of sunshine per day.
Monthly Temperature in Iiyama
Visitors to Iiyama can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a comfortable 29°C (84°F) in August, the warmest time of the year, to a chilly 3°C (37°F) during cooler months like January.
At night, you can expect temperatures ranging from 20°C (68°F) in August to around -5°C (23°F) during January.Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Iiyama
Iiyama is known for its substantial rain/snowfall, with annual precipitation reaching 2163 mm (85 in). While rainfall varies throughout the year, each season offers its own charm. July brings wetter days averaging 257 mm (10 in) of precipitation, spread over 21 rainy days.
In contrast, the driest month April experiences a drier climate, with about 126 mm (5 in) of rainfall spread across 17 rainy days. For more details, please visit our Iiyama Precipitation page.The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Iiyama
Seasonal changes in sunshine hours are quite dramatic in Iiyama. While May receives considerable daily sunshine with up to 6.6 hours, January marks the darkest time of the year, where sunshine is scarce with only 2.2 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Humidity in Iiyama by Month
The relative humidity is high throughout the year in Iiyama.
The city experiences its highest humidity in July, reaching 80%. In April, the humidity drops to its lowest level at 67%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Iiyama 3-Day Forecast
Check the conditions for any month of the year.
Best Time to Visit Iiyama
During May, Iiyama experiences its most favorable weather, with temperatures of 21°C (69°F). These mild conditions make it an excellent time for a visit.The weather brings rainfall of 142 mm (5.6 in) during this period.
Plan accordingly for January, February, June, July, August, September, October and December, when conditions bring the heaviest precipitation. Looking for inspiration on where to travel this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.
