December weather forecastIruma, Japan

December

Weather in December

December, the first month of the winter in Iruma, is still a cool month, with an average temperature varying between 10.5°C (50.9°F) and 4.3°C (39.7°F).

Temperature

The onset of December is marked by a decrease in temperature, transitioning from a moderate 15.8°C (60.4°F) in November to a cool 10.5°C (50.9°F). Iruma reports an average low-temperature of 4.3°C (39.7°F) during the nights of December.

Humidity

The average relative humidity in December in Iruma is 61%.

Rainfall

December is the month with the least rainfall. Rain falls for 5.8 days and accumulates 21mm (0.83") of precipitation.

Snowfall

In Iruma, Japan, snow does not fall in April through October and December.

Daylight

With an average of 9h and 48min of daylight, December has the shortest days of the year in Iruma, Japan.
On the first day of December, sunrise is at 06:34 and sunset at 16:28. On the last day of the month, sunrise is at 06:52 and sunset at 16:38 JST.

Sunshine

In Iruma, Japan, the average sunshine in December is 6.5h.

UV index

The average daily maximum UV index in December is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A daily maximum UV index of 3 in December translates into the following instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.

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

Frequently asked questions

In Iruma, 10.5°C (50.9°F) is the average high-temperature and 4.3°C (39.7°F) is the average low-temperature during December. In September, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 30°C (86°F).

In Iruma, Japan, the average relative humidity in December is 61%.

The month with the least rainfall in Iruma is December, when the rain falls for 5.8 days and typically collects 21mm (0.83") of precipitation.

In Iruma, Japan, in December, during 5.8 rainfall days, 21mm (0.83") of precipitation is typically accumulated.

In Iruma, snow does not fall in April through October and December.

In December, in Iruma, it doesn't snow. November is the latest month when it typically snows.

The month with the shortest days in Iruma is December, with an average of 9h and 48min of daylight.

In Iruma, the average day length in December is 9h and 47min.

On the first day of December in Iruma, sunrise is at 06:34 and sunset at 16:28. On the last day of the month, sunrise is at 06:52 and sunset at 16:38 JST.

In Iruma, Japan, the average sunshine duration in December is 6.5h.

In December, the average daily maximum UV index in Iruma is 3. A UV Index estimate of 3 to 5 represents a moderate vulnerability from unsafe 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

15.8°C

10.5°C

8.4°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

9.8km/h

11.6km/h

12.4km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

19.2

24.5

25.3

Average UV index

Average cloud cover

Average visibility

Average temperature in December
Iruma, Japan

Average high temperature in December: 10.5°C

The warmest month (with the highest average high temperature) is August (32°C).
The month with the lowest average high temperature is January (8.4°C).

Average low temperature in December: 4.3°C

The month with the highest average low temperature is August (24.7°C).
The coldest month (with the lowest average low temperature) is January (1.4°C).

Average pressure in December
Iruma, Japan

Average pressure in December: 1016.6mbar

The month with the highest atmospheric pressure is November (1018.4mbar).
The month with the lowest atmospheric pressure is June (1009.2mbar).

Average wind speed in December
Iruma, Japan

Average wind speed in December: 10.3km/h

The windiest month (with the highest average wind speed) is April (11.5km/h).
The calmest month (with the lowest average wind speed) is July (8.7km/h).

Average humidity in December
Iruma, Japan

Average humidity in December: 61%

The months with the highest relative humidity are June and July (73%).
The month with the lowest relative humidity is January (58%).

Average rainfall in December
Iruma, Japan

Average rainfall in December: 21mm

The wettest month (with the highest rainfall) is October (102mm).
The driest month (with the least rainfall) is December (21mm).

Average rainfall days in December
Iruma, Japan

Average rainfall days in December: 5.8 days

The month with the highest number of rainy days is June (18.5 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in December
Iruma, Japan

Average snowfall in December: 0mm

The month with the highest snowfall is February (39mm).
The months with the least snowfall are April, May, June, July, August, September, October and December (0mm).

Average snowfall days in December
Iruma, Japan

Average snowfall days in December: 0 days

The month with the highest number of snowfall days is February (2.1 days).
The months with the least snowfall days are April, May, June, July, August, September, October and December (0 days).

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

Average daylight in December: 9h and 48min

The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).

Average sunshine in December: 6h and 30min

The month with the most sunshine is August (Average sunshine: 9h and 48min).
The months with the least sunshine are February and November (Average sunshine: 6h and 12min).

Average sunshine days in December
Iruma, Japan

Average sunshine days in December: 24.5 days

The month with the most sunshine days is January (25.3 days).
The month with the least sunshine days is June (9.1 days).

Average UV index in December
Iruma, Japan

Average UV index in December: 3

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is January (UV index 2).

Average cloud cover in December
Iruma, Japan

Average cloud cover in December: 28

The month with the most cloud cover is June (Cloud cover 45).
The month with the least cloud cover is January (Cloud cover 26).

Average visibility in December
Iruma, Japan

Average visibility in December: 10km

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