Iiyama Weather in December
Thinking of visiting Iiyama in December? Expect low temperatures reaching 6°C (43°F) during the day, dropping to -3°C (27°F) at night. Heavy showers are common during the rainy season.
Rainfall in Iiyama in December
As part of the rainy season, Iiyama sees around 22 days of rain in December, with an average of 187 mm (7.4 in). Rainy season showers tend to be fairly substantial. A good rain jacket or umbrella is worth having with you most days.
Temperature in Iiyama in December
In December, Iiyama gets low temperatures, with highs of 6°C (43°F). Nights cool to around -3°C (27°F). December is part of winter. It stays cool throughout the day, so warm layers are a good idea from morning to evening. At -3°C (27°F) overnight, frost and ice are likely outside. Indoors, consider packing an extra blanket if you're unsure about the heating.
Sunshine in Iiyama in December
The city usually sees around 79 hours of sunlight, indicating fewer sunny days.If you prefer dry days with pleasant temperatures, December may not be the ideal month to visit Iiyama. Our weather planner can help you explore destinations with more pleasant weather conditions.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Japan, check out our Iiyama's climate page.
Iiyama Temperature in December
Min Temperature
-3°C (27°F)
Max Temperature
6°C (43°F)
Chance of Rain
75%
Precipitation
187 mm (7.4 in)
Rainy days
22 days
Humidity
76% *
Sunshine
79 hours *
Percentage Sunshine
*
Daily Historical Temperatures
49-year average (1976-2025)
Based on our historical records, temperatures in Iiyama typically drop from around 10°C (50°F) at the start of December to approximately 5°C (41°F) by the end. Nights are cold, with lows typically ranging from -1°C (30°F) to 3°C (37°F).
Average temperatures in December
Daily Historical Precipitation
49-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for Iiyama in December
Browse day-by-day weather records for Iiyama spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Iiyama historical weather extremes in December
According to our 19 years of weather records for Iiyama, the following extremes were recorded between 2006 and 2025.
- The warmest day in December was on December 4, 2018, with a maximum of 21°C (70°F).
- The lowest daytime temperature in December was -1°C (30°F), recorded on December 27, 2025.
- Iiyama registered its coldest December night on December 6, 2025, with temperatures dropping to -8°C (18°F).
- Peak precipitation in December occurred on December 27, 2006, when 64 mm (2.5 in) of precipitation was measured.
Best Places in Japan in December
Find out more about the weather in Japan and which places have the best travel conditions in this month. See all of Japan in December →
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What to Wear in Iiyama in December
Cold weather calls for smart layering in December. A thermal base layer makes a huge difference in staying warm. Add a wool sweater or fleece, then a wind-resistant outer jacket. Heavy rain is guaranteed, please bring a good poncho and waterproof everything! You can probably leave your sunglasses at home, because sunny days are pretty rare this month.What To Do in Iiyama in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Japan, check out our Iiyama's climate page.
Temperature Rainfall Sunshine Humidity
See the full Iiyama climate overview or explore weather in Japan.
