December weather forecastIwai, Japan

December

Weather in December

The first month of the winter, December, is still a cool month in Iwai, Japan, with temperature in the range of an average high of 10.5°C (50.9°F) and an average low of 4.3°C (39.7°F).

Temperature

The transition into December indicates a reduction in the average high-temperature, down to a fresh 10.5°C (50.9°F) from November's refreshing 16°C (60.8°F). Iwai witnesses a consistent average low-temperature of 4.3°C (39.7°F) throughout December.

Humidity

In Iwai, the average relative humidity in December is 63%.

Rainfall

The month with the least rainfall in Iwai is December, when the rain falls for 7.8 days and typically collects 31mm (1.22") of precipitation.

Snowfall

In Iwai, snow does not fall in April through December.

Daylight

With an average of 9h and 48min of daylight, December has the shortest days of the year.
On the first day of December in Iwai, sunrise is at 06:32 and sunset at 16:26. On the last day of the month, sunrise is at 06:50 and sunset at 16:36 JST.

Sunshine

In December, the average sunshine in Iwai is 6.1h.

UV index

The months with the lowest UV index in Iwai are January and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: In December, the maximum UV index of 2 suggests this advice:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Boost your sun resistance with garments that are densely woven yet spacious.

Frequently asked questions

December temperatures vary between a high-temperature of 10.5°C (50.9°F) and a low-temperature of 4.3°C (39.7°F). In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is evaluated at 30°C (86°F).

In Iwai, the average relative humidity in December is 63%.

December is the month with the least rainfall in Iwai. Rain falls for 7.8 days and accumulates 31mm (1.22") of precipitation.

In Iwai, in December, during 7.8 rainfall days, 31mm (1.22") of precipitation is typically accumulated.

April through December are months without snowfall in Iwai.

In Iwai, in December, it doesn't snow. In January, it regularly snows.

December has the shortest days of the year, with an average of 9h and 48min of daylight.

The average day length in December in Iwai, Japan, is 9h and 46min.

On the first day of December in Iwai, sunrise is at 06:32 and sunset at 16:26. On the last day of the month, sunrise is at 06:50 and sunset at 16:36 JST.

In Iwai, the average sunshine duration in December is 6.1h.

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

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

  • Average high temperature in December: 10.5°C

The warmest month (with the highest average high temperature) is August (31.9°C).
The month with the lowest average high temperature is January (8.3°C).

  • Average low temperature in December: 4.3°C

The month with the highest average low temperature is August (24.4°C).
The coldest month (with the lowest average low temperature) is January (1.7°C).

Average pressure in December
Iwai, Japan

  • Average pressure in December: 1016.3mbar

The month with the highest atmospheric pressure is November (1018.2mbar).
The month with the lowest atmospheric pressure is June (1009.2mbar).

Average wind speed in December
Iwai, Japan

  • Average wind speed in December: 10.5km/h

The windiest month (with the highest average wind speed) is April (12.3km/h).
The calmest month (with the lowest average wind speed) is November (9.1km/h).

Average humidity in December
Iwai, Japan

  • Average humidity in December: 63%

The months with the highest relative humidity are June and July (76%).
The month with the lowest relative humidity is January (60%).

Average rainfall in December
Iwai, Japan

  • Average rainfall in December: 31mm

The wettest month (with the highest rainfall) is October (122mm).
The driest month (with the least rainfall) is December (31mm).

Average rainfall days in December
Iwai, Japan

  • Average rainfall days in December: 7.8 days

The month with the highest number of rainy days is July (18.7 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in December
Iwai, Japan

  • Average snowfall in December: 0mm

The month with the highest snowfall is February (36mm).
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0mm).

Average snowfall days in December
Iwai, Japan

  • Average snowfall days in December: 0 days

The month with the highest number of snowfall days is February (2 days).
The months with the least snowfall days are April, May, June, July, August, September, October, November and December (0 days).

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

  • Average daylight in December: 9h and 48min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • Average sunshine in December: 6h and 6min

The month with the most sunshine is August (Average sunshine: 9h and 42min).
The month with the least sunshine is February (Average sunshine: 5h and 42min).

Average sunshine days in December
Iwai, Japan

  • Average sunshine days in December: 21.9 days

The month with the most sunshine days is January (23.3 days).
The month with the least sunshine days is June (9.7 days).

Average UV index in December
Iwai, 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
Iwai, Japan

  • Average cloud cover in December: 31

The month with the most cloud cover is June (Cloud cover 49).
The month with the least cloud cover is January (Cloud cover 29).

Average visibility in December
Iwai, Japan

  • Average visibility in December: 10km

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