December weather forecast
Iwanuma, Japan

December

Weather in December

The first month of the winter, December, is also a frosty month in Iwanuma, Japan, with an average temperature varying between 6.6°C (43.9°F) and 1.9°C (35.4°F).

Temperature

December's arrival corresponds with a decrease in average high-temperatures, from November's fresh 12.5°C (54.5°F) to a frosty 6.6°C (43.9°F). Iwanuma encounters a small divergence from daytime high temperatures, averaging a low-temperature of 1.9°C (35.4°F) during December nights.

Humidity

In Iwanuma, Japan, the average relative humidity in December is 75%.

Rainfall

In Iwanuma, during December, the rain falls for 9.3 days and regularly aggregates up to 28mm (1.1") of precipitation. Throughout the year, in Iwanuma, there are 141.6 rainfall days, and 753mm (29.65") of precipitation is accumulated.

Snowfall

Months with snowfall are January through April and December. December is the first month it typically snows in Iwanuma. Throughout December, in the average 3.2 snowfall days, it receives 20mm (0.79") of snow. Throughout the year, in Iwanuma, Japan, there are 19.2 snowfall days, and 203mm (7.99") of snow is accumulated.

Daylight

With an average of 9h and 36min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 06:34 and sunset at 16:17. On the last day of December, in Iwanuma, sunrise is at 06:52 and sunset at 16:26 JST.

Sunshine

In December, the average sunshine is 5.6h.

UV index

January through March and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.

Frequently asked questions

Is it cold in Iwanuma during December?
December temperatures vary between a high-temperature of 6.6°C (43.9°F) and a low-temperature of 1.9°C (35.4°F). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines relative humidity and air temperature, in August is calculated to be 31°C (87.8°F).
What is the average humidity in December in Iwanuma?
In December, the average relative humidity in Iwanuma is 75%.
How many days does it rain in December in Iwanuma?
In Iwanuma, in December, it is raining for 9.3 days, with typically 28mm (1.1") of accumulated precipitation.
When does it start snowing in Iwanuma?
December is the first month it typically snows in Iwanuma, Japan. Throughout December, in the average 3.2 snowfall days, it receives 20mm (0.79") of snow.
What is the month with the shortest days in Iwanuma?
The month with the shortest days is December, with an average of 9h and 36min of daylight.
How many hours of daylight does Iwanuma have in December?
In December, the average day length in Iwanuma, Japan, is 9h and 34min.
When are sunrise and sunset in December in Iwanuma?
In December, on the first day of the month, sunrise is at 06:34 and sunset at 16:17. On the last day of the month, in Iwanuma, sunrise is at 06:52 and sunset at 16:26 JST.
How many hours of sunshine does Iwanuma have in December?
In December, the average sunshine duration in Iwanuma, Japan, is 5.6h.
When is the lowest UV index in Iwanuma?
January through March and December, with an average maximum UV index of 2, are months with the lowest UV index in Iwanuma.
How high is the UV index in December in Iwanuma?
In December, the average daily maximum UV index in Iwanuma, Japan, is 2. A UV Index of 2, and less, symbolizes a low health risk 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 daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility
Average temperature in December
Iwanuma, Japan
  • Average high temperature in December: 6.6°C

The warmest month (with the highest average high temperature) is August (27.6°C).
The month with the lowest average high temperature is January (3.6°C).

  • Average low temperature in December: 1.9°C

The month with the highest average low temperature is August (21.5°C).
The coldest month (with the lowest average low temperature) is February (-1.2°C).

Average pressure in December
Iwanuma, Japan
  • Average pressure in December: 1016.3mbar

The month with the highest atmospheric pressure is November (1018.7mbar).
The month with the lowest atmospheric pressure is June (1009.3mbar).

Average wind speed in December
Iwanuma, Japan
  • Average wind speed in December: 15km/h

The windiest month (with the highest average wind speed) is January (15.4km/h).
The calmest month (with the lowest average wind speed) is July (8.4km/h).

Average humidity in December
Iwanuma, Japan
  • Average humidity in December: 75%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is April (72%).

Average rainfall in December
Iwanuma, Japan
  • Average rainfall in December: 28mm

The wettest month (with the highest rainfall) is July (118mm).
The driest month (with the least rainfall) is February (22mm).

Average rainfall days in December
Iwanuma, Japan
  • Average rainfall days in December: 9.3 days

The month with the highest number of rainy days is July (19.6 days).
The month with the least rainy days is February (6.1 days).

Average snowfall in December
Iwanuma, Japan
  • Average snowfall in December: 20mm

The month with the highest snowfall is January (67mm).
The months with the least snowfall are May, June, July, August, September, October and November (0mm).

Average snowfall days in December
Iwanuma, Japan
  • Average snowfall days in December: 3.2 days

The month with the highest number of snowfall days is January (7 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
Iwanuma, Japan
  • Average daylight in December: 9h and 4min

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

  • Average sunshine in December: 5h and 4min

The month with the most sunshine is May (Average sunshine: 9h and 36min).
The months with the least sunshine are January and February (Average sunshine: 5h and 6min).

Average sunshine days in December
Iwanuma, Japan
  • Average sunshine days in December: 18.3 days

The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is July (8.6 days).

Average UV index in December
Iwanuma, Japan
  • Average UV index in December: 2

The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).

Average cloud cover in December
Iwanuma, Japan
  • Average cloud cover in December: 43

The month with the most cloud cover is July (Cloud cover 48).
The month with the least cloud cover is May (Cloud cover 35).

Average visibility in December
Iwanuma, Japan
  • Average visibility in December: 10km

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

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