December weather forecast
River, IN

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Weather in December

The first month of the winter, December, is also an icy month in River, Indiana, with an average temperature varying between 26.6°F (-3°C) and 36.5°F (2.5°C).

Temperature

December's onset brings a reduction in the average high-temperature, from a frosty 47.3°F (8.5°C) in November to a wintry 36.5°F (2.5°C). River, during December, witnesses an average low-temperature of 26.6°F (-3°C).

Humidity

The average relative humidity in December in River is 83%.

Rainfall

In River, Indiana, in December, during 8.5 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. Throughout the year, in River, there are 153.8 rainfall days, and 25" (635mm) of precipitation is accumulated.

Snowfall

January through April, October through December are months with snowfall in River. In River, in December, snow falls for 10.1 days, with typically accumulated 1.93" (49mm) of snow. In River, Indiana, during the entire year, snow falls for 47.8 days and aggregates up to 11.93" (303mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 18min of daylight.
On the first day of December in River, sunrise is at 7:47 am and sunset at 5:15 pm. On the last day of the month, sunrise is at 8:06 am and sunset at 5:24 pm EST.

Sunshine

In River, Indiana, the average sunshine in December is 3.8h.

UV index

January through March, October through 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 low health risk from unsafe exposure to UV radiation for the average person.
Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in River?

The high-temperature during December is 36.5°F (2.5°C) and the low-temperature is 26.6°F (-3°C). The average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in July is calculated to be 86°F (30°C).

What is the average humidity in December in River?

The average relative humidity in December in River is 83%.

How many days does it rain in December in River?

In December, the rain falls for 8.5 days. Throughout December, 1.57" (40mm) of precipitation is accumulated.

How many days does it snow in December in River?

In December, in River, it is snowing for 10.1 days. Throughout December, 1.93" (49mm) of snow is accumulated.

What is the month with the shortest days in River?

The month with the shortest days is December, with an average of 9h and 18min of daylight.

What is the average length of the day in December in River?

The average day length in December in River is 9h and 19min.

When are sunrise and sunset in December in River?

In December, on the first day of the month, sunrise is at 7:47 am and sunset at 5:15 pm. On the last day of the month, in River, Indiana, sunrise is at 8:06 am and sunset at 5:24 pm EST.

How many hours of sunshine does River have in December?

In River, the average sunshine duration in December is 3.8h.

When is the lowest UV index in River?

The months with the lowest UV index in River are January through March, October through December, with an average maximum UV index of 2.

What is the UV index intensity in December in River?

In December, the average daily maximum UV index in River, Indiana, is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
River, IN

Average temperature in December - River, IN
  • Average high temperature in December: 36.5°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.7°F).

  • Average low temperature in December: 26.6°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).

Average pressure in December
River, IN

Average pressure in December - River, IN
  • Average pressure in December: 30.1"Hg

The months with the highest atmospheric pressure are January and November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
River, IN

Average wind speed in December - River, IN
  • Average wind speed in December: 9.6mph

The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).

Average humidity in December
River, IN

Average humidity in December - River, IN
  • Average humidity in December: 83%

The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (75%).

Average rainfall in December
River, IN

Average rainfall in December - River, IN
  • Average rainfall in December: 1.57"

The wettest month (with the highest rainfall) is April (3.07").
The driest month (with the least rainfall) is February (1.42").

Average rainfall days in December
River, IN

Average rainfall days in December - River, IN
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (6.8 days).

Average snowfall in December
River, IN

Average snowfall in December - River, IN
  • Average snowfall in December: 1.93"

The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
River, IN

Average snowfall days in December - River, IN
  • Average snowfall days in December: 10.1 days

The month with the highest number of snowfall days is January (13.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
River, IN

Average daylight in December / Average sunshine in December - River, IN
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 18min).

Average sunshine days in December
River, IN

Average sunshine days in December - River, IN
  • Average sunshine days in December: 13.7 days

The month with the most sunshine days is October (16 days).
The months with the least sunshine days are February and May (10.5 days).

Average UV index in December
River, IN

Average UV index in December - River, IN
  • Average UV index in December: 2

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).

Average cloud cover in December
River, IN

Average cloud cover in December - River, IN
  • Average cloud cover in December: 61

The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
River, IN

Average visibility in December - River, IN
  • Average visibility in December: 6mi

The months with the highest visibility are February, March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January and August (5mi).

River, Indiana, USA

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