December weather forecast
Iowa City, IA

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Golden and brown trees in a scenic, neat lawn near the mighty grandeur of the Old Capitol building, Iowa City
Golden and brown trees in a scenic, neat lawn near the mighty grandeur of the Old Capitol building, Iowa City

Weather in December

December ushers in the winter season, with temperatures dipping well below freezing, particularly at night, reaching lows of 22.8°F (-5.1°C). Snowfall becomes frequent, contributing to a thick white blanket enveloping the city. Cold winds carry the unmistakable scent of the approaching holidays, completing the quintessential winter scene.

Temperature

With December's onset, the average high-temperature recedes from November's chilly 46.4°F (8°C) to an icy 34°F (1.1°C). In the month of December, Iowa City's average low-temperature falls to a freezing cold 22.8°F (-5.1°C).

Humidity

In December, the average relative humidity is 80%.

Rainfall

In Iowa City, during December, the rain falls for 7 days and regularly aggregates up to 1.46" (37mm) of precipitation. In Iowa City, during the entire year, the rain falls for 140.4 days and collects up to 29.57" (751mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In Iowa City, in December, snow falls for 8.4 days, with typically accumulated 2.28" (58mm) of snow. Throughout the year, there are 37.7 snowfall days, and 16.42" (417mm) of snow is accumulated.

Daylight

The month with the shortest days in Iowa City is December, with an average of 9h and 12min of daylight.
On the first day of the month, sunrise is at 7:14 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:32 am and sunset at 4:45 pm CST.

Sunshine

In December, the average sunshine is 4.4h.

UV index

The average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.

Frequently asked questions

How cold is December?

In December, the average high-temperature and low-temperature are 34°F (1.1°C) and 22.8°F (-5.1°C) respectively. The average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines air temperature and relative humidity, in August is estimated at 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December in Iowa City is 80%.

How much does it rain in December?

In Iowa City, in December, it is raining for 7 days, with typically 1.46" (37mm) of accumulated precipitation.

How much does it snow in December?

In Iowa City, in December, snow falls for 8.4 days, with typically accumulated 2.28" (58mm) of snow.

What is the month with the shortest days in Iowa City?

With an average of 9h and 12min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

In December, the average day length is 9h and 13min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 7:14 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 4:45 pm CST.

How many hours of sunshine does Iowa City have in December?

In Iowa City, the average sunshine duration in December is 4.4h.

What is the UV index intensity in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to UV radiation.
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
Iowa City, IA

Average temperature in December - Iowa City, IA
  • Average high temperature in December: 34°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.3°F).

  • Average low temperature in December: 22.8°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).

Average pressure in December
Iowa City, IA

Average pressure in December - Iowa City, IA
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
Iowa City, IA

Average wind speed in December - Iowa City, IA
  • Average wind speed in December: 9.9mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).

Average humidity in December
Iowa City, IA

Average humidity in December - Iowa City, IA
  • Average humidity in December: 80%

The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Iowa City, IA

Average rainfall in December - Iowa City, IA
  • Average rainfall in December: 1.46"

The wettest month (with the highest rainfall) is May (4.69").
The driest months (with the least rainfall) are January and February (1.34").

Average rainfall days in December
Iowa City, IA

Average rainfall days in December - Iowa City, IA
  • Average rainfall days in December: 7 days

The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (5 days).

Average snowfall in December
Iowa City, IA

Average snowfall in December - Iowa City, IA
  • Average snowfall in December: 2.28"

The month with the highest snowfall is January (5.28").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Iowa City, IA

Average snowfall days in December - Iowa City, IA
  • Average snowfall days in December: 8.4 days

The month with the highest number of snowfall days is January (10.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Iowa City, IA

Average daylight in December / Average sunshine in December - Iowa City, IA
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).

Average sunshine days in December
Iowa City, IA

Average sunshine days in December - Iowa City, IA
  • Average sunshine days in December: 17 days

The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10 days).

Average UV index in December
Iowa City, IA

Average UV index in December - Iowa City, IA
  • Average UV index in December: 2

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in December
Iowa City, IA

Average cloud cover in December - Iowa City, IA
  • Average cloud cover in December: 53

The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in December
Iowa City, IA

Average visibility in December - Iowa City, IA
  • Average visibility in December: 6mi

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

Iowa City, Iowa, USA

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