December weather forecastKoya, Japan

December

Weather in December

The first month of the winter, December, is still a chilly month in Koya, Japan, with temperature in the range of an average low of 2.5°C (36.5°F) and an average high of 8.9°C (48°F).

Temperature

As November transitions into December, Koya sees a drop in the average high-temperature, transitioning from a mild 14.9°C (58.8°F) to a chilly 8.9°C (48°F). Throughout December, Koya's nights cool down to an average of 2.5°C (36.5°F).

Humidity

The average relative humidity in December in Koya is 78%.

Rainfall

In Koya, during December, the rain falls for 16.7 days and regularly aggregates up to 66mm (2.6") of precipitation. In Koya, during the entire year, the rain falls for 199.5 days and collects up to 1277mm (50.28") of precipitation.

Snowfall

Months with snowfall are January through April and December. December is the first month it typically snows in Koya. Throughout December, in the average 4.9 snowfall days, it receives 35mm (1.38") of snow. In Koya, during the entire year, snow falls for 25.9 days and aggregates up to 201mm (7.91") of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 54min of daylight.
On the first day of the month, sunrise is at 06:45 and sunset at 16:48. On the last day of December, sunrise is at 07:03 and sunset at 16:58 JST.

Sunshine

In Koya, the average sunshine in December is 5.3h.

UV index

The months with the lowest UV index in Koya are January, February and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for average individuals.
Note: The daily maximum UV index of 2 in December interprets into the following advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.

Frequently asked questions

The average high-temperature, in December, in Koya, is 8.9°C (48°F), while the average low-temperature is 2.5°C (36.5°F). In August, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which represents the influence of relative humidity on air temperature, is evaluated at 37°C (98.6°F).

In Koya, Japan, the average relative humidity in December is 78%.

In Koya, during December, the rain falls for 16.7 days and regularly aggregates up to 66mm (2.6") of precipitation.

December is the first month it typically snows in Koya. Throughout December, in the average 4.9 snowfall days, it receives 35mm (1.38") of snow.

The month with the shortest days is December, with an average of 9h and 54min of daylight.

The average day length in December in Koya, Japan, is 9h and 55min.

In December, on the first day of the month, sunrise is at 06:45 and sunset at 16:48. On the last day of the month, in Koya, sunrise is at 07:03 and sunset at 16:58 JST.

The average sunshine duration in December in Koya is 5.3h.

The months with the lowest UV index in Koya, Japan, are January, February and December, with an average maximum UV index of 2.

In December, the average daily maximum UV index in Koya is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Koya, Japan

  • Average high temperature in December: 8.9°C

The warmest month (with the highest average high temperature) is August (29.9°C).
The month with the lowest average high temperature is January (6.7°C).

  • Average low temperature in December: 2.5°C

The month with the highest average low temperature is August (22.3°C).
The coldest month (with the lowest average low temperature) is January (0.1°C).

Average pressure in December
Koya, Japan

  • Average pressure in December: 1019.2mbar

The month with the highest atmospheric pressure is February (1019.5mbar).
The month with the lowest atmospheric pressure is June (1008.8mbar).

Average wind speed in December
Koya, Japan

  • Average wind speed in December: 9km/h

The windiest month (with the highest average wind speed) is January (9.5km/h).
The calmest months (with the lowest average wind speed) are June and August (6.2km/h).

Average humidity in December
Koya, Japan

  • Average humidity in December: 78%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is May (74%).

Average rainfall in December
Koya, Japan

  • Average rainfall in December: 66mm

The wettest month (with the highest rainfall) is July (179mm).
The driest month (with the least rainfall) is January (56mm).

Average rainfall days in December
Koya, Japan

  • Average rainfall days in December: 16.7 days

The month with the highest number of rainy days is July (21.1 days).
The month with the least rainy days is February (13.8 days).

Average snowfall in December
Koya, Japan

  • Average snowfall in December: 35mm

The month with the highest snowfall is January (90mm).
The months with the least snowfall are May, June, July, August, September, October and November (0mm).

Average snowfall days in December
Koya, Japan

  • Average snowfall days in December: 4.9 days

The month with the highest number of snowfall days is January (11.1 days).
The months with the least snowfall days are May, June, July, August, September, October and November (0 days).

Average daylight in December /
Average sunshine in December
Koya, Japan

  • Average daylight in December: 9h and 54min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in December: 5h and 18min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The months with the least sunshine are January and February (Average sunshine: 5h and 12min).

Average sunshine days in December
Koya, Japan

  • Average sunshine days in December: 8.8 days

The month with the most sunshine days is May (14.3 days).
The month with the least sunshine days is July (7.9 days).

Average UV index in December
Koya, Japan

  • Average UV index in December: 2

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February and December (UV index 2).

Average cloud cover in December
Koya, Japan

  • Average cloud cover in December: 43

The month with the most cloud cover is January (Cloud cover 46).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
Koya, Japan

  • Average visibility in December: 9km

The months with the highest visibility are January, February, March, April, May, August, September, October, November and December (9km).
The months with the lowest visibility are June and July (8km).