December weather forecastYanai, Japan

December

Weather in December

December, the first month of the winter in Yanai, is still a cool month, with temperature in the range of an average low of 6.5°C (43.7°F) and an average high of 10.6°C (51.1°F).

Temperature

The onset of December brings a small change in high-temperatures, falling from a refreshing 16°C (60.8°F) in November to a fresh 10.6°C (51.1°F). Yanai encounters a small divergence from daytime high temperatures, averaging a low-temperature of 6.5°C (43.7°F) during December nights.

Humidity

The average relative humidity in December is 73%.

Rainfall

In Yanai, in December, during 14.7 rainfall days, 68mm (2.68") of precipitation is typically accumulated. In Yanai, during the entire year, the rain falls for 168 days and collects up to 1163mm (45.79") of precipitation.

Snowfall

January, February and December are months with snowfall. The month with the most snowfall is December, when snow falls for 1.8 days and typically aggregates up to 8mm (0.31") of snow.

Sea temperature

In Yanai, the average seawater temperature in December is 17.2°C (63°F).
Note: Most people find swimming in 17.2°C (63°F) unenjoyable. As the water temperature falls from 21°C (69.8°F) to 15°C (59°F), controlling one's breathing becomes harder.

Daylight

With an average of 9h and 54min of daylight, December has the shortest days of the year in Yanai.
On the first day of the month, sunrise is at 06:58 and sunset at 17:02. On the last day of December, in Yanai, Japan, sunrise is at 07:16 and sunset at 17:12 JST.

Sunshine

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

UV index

January and December, with an average maximum UV index of 2, are months with the lowest UV index in Yanai. A UV Index estimate of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the average person.
Note: During December, 2 as the daily maximum UV index converts into the following advice:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.

Updated: Jan 31, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In Yanai, 10.6°C (51.1°F) is the average high-temperature and 6.5°C (43.7°F) is the average low-temperature during December. The average heat index (a.k.a. 'apparent temperature', 'feels like'), which represents the influence of relative humidity on air temperature, in August is appraised at 35°C (95°F).

The average relative humidity in December in Yanai, Japan, is 73%.

In Yanai, during December, the rain falls for 14.7 days and regularly aggregates up to 68mm (2.68") of precipitation.

December is the month with the most snowfall in Yanai. Snow falls for 1.8 days and accumulates 8mm (0.31") of snow.

December is the first month it typically snows. Throughout December, in the average 1.8 snowfall days, it receives 8mm (0.31") of snow.

In December, the average sea temperature in Yanai, Japan, is 17.2°C (63°F). For most, swimming in 17.2°C (63°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).

With an average of 9h and 54min of daylight, December has the shortest days of the year in Yanai.

In Yanai, Japan, the average day length in December is 9h and 56min.

In December, on the first day of the month, sunrise is at 06:58 and sunset at 17:02. On the last day of the month, in Yanai, Japan, sunrise is at 07:16 and sunset at 17:12 JST.

In December, the average sunshine duration in Yanai is 5.3h.

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

In Yanai, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health threat from exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A S O N December

Nov

December

Jan

Average high temperature

16°C

10.6°C

8.7°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

12.6km/h

15.2km/h

15.6km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

1.8

3.3

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

17.2

11.9

13.8

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Yanai, Japan

Average high temperature in December: 10.6°C

The warmest month (with the highest average high temperature) is August (29.1°C).
The month with the lowest average high temperature is January (8.7°C).

Average low temperature in December: 6.5°C

The month with the highest average low temperature is August (24.3°C).
The coldest month (with the lowest average low temperature) is January (4.3°C).

Average pressure in December
Yanai, Japan

Average pressure in December: 1020.8mbar

The month with the highest atmospheric pressure is January (1021.3mbar).
The month with the lowest atmospheric pressure is June (1008.4mbar).

Average wind speed in December
Yanai, Japan

Average wind speed in December: 14.1km/h

The windiest month (with the highest average wind speed) is January (14.5km/h).
The calmest month (with the lowest average wind speed) is June (8km/h).

Average humidity in December
Yanai, Japan

Average humidity in December: 73%

The month with the highest relative humidity is July (85%).
The months with the lowest relative humidity are January, February and March (71%).

Average rainfall in December
Yanai, Japan

Average rainfall in December: 68mm

The wettest month (with the highest rainfall) is July (213mm).
The driest month (with the least rainfall) is January (39mm).

Average rainfall days in December
Yanai, Japan

Average rainfall days in December: 14.7 days

The month with the highest number of rainy days is July (20.5 days).
The month with the least rainy days is October (10.5 days).

Average snowfall in December
Yanai, Japan

Average snowfall in December: 8mm

The month with the highest snowfall is December (8mm).
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0mm).

Average snowfall days in December
Yanai, Japan

Average snowfall days in December: 1.8 days

The month with the highest number of snowfall days is January (3.3 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).

Average sea temperature in December
Yanai, Japan

Average sea temperature in December: 17.2°C

The best month for swimming (with the highest average sea temperature) is August (26.8°C).
The coldest month (with the lowest average sea temperature) is February (12.9°C).

Average daylight in December /
Average sunshine in December
Yanai, 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 month with the least sunshine is January (Average sunshine: 5h and 0min).

Average sunshine days in December
Yanai, Japan

Average sunshine days in December: 11.9 days

The month with the most sunshine days is May (18.6 days).
The month with the least sunshine days is July (9.3 days).

Average UV index in December
Yanai, 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 and December (UV index 2).

Average cloud cover in December
Yanai, Japan

Average cloud cover in December: 40

The months with the most cloud cover are January and June (Cloud cover 43).
The months with the least cloud cover are August, October and November (Cloud cover 32).

Average visibility in December
Yanai, Japan

Average visibility in December: 10km

The months with the highest visibility are January, February, March, August, September, October, November and December (10km).
The months with the lowest visibility are April, May, June and July (9km).