December weather forecast
Marshalltown, IA

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Weather in December

December in Marshalltown signifies the onset of winter with its colder temperatures and an increase in snowfall to 1.14" (29mm). The weather pattern clearly differs from November, signifying the prominence of winter. Shorter daylight hours and colder evenings begin to dominate the climate. The snow starts to coat the cityscape, transforming Marshalltown into a winter wonderland. Despite the chilly weather, December carries a charm of its own, marking the end of the year with a beautiful snowy landscape.

Temperature

The arrival of December in Marshalltown signals a shift in temperature, down from a chilly 45.1°F (7.3°C) in November to a wintry 32°F (0°C). During the month of December, an average temperature of 21°F (-6.1°C) is noted during the nights in Marshalltown.

Humidity

The average relative humidity in December is 82%.

Rainfall

In Marshalltown, Iowa, in December, during 4.8 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. Throughout the year, in Marshalltown, Iowa, there are 118.2 rainfall days, and 16.18" (411mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall in Marshalltown. In December, in Marshalltown, it is snowing for 7.5 days. Throughout December, 1.14" (29mm) of snow is accumulated. In Marshalltown, during the entire year, snow falls for 34.6 days and aggregates up to 6.97" (177mm) of snow.

Daylight

The month with the shortest days in Marshalltown, Iowa, is December, with an average of 9h and 12min of daylight.
On the first day of December in Marshalltown, sunrise is at 7:20 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:50 pm CST.

Sunshine

In December, the average sunshine in Marshalltown is 4.4h.

UV index

The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: In December, the maximum UV index of 2 translates into these guidelines:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
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Frequently asked questions

How cold is it in Marshalltown in December?

In Marshalltown, 32°F (0°C) is the average high-temperature and 21°F (-6.1°C) is the average low-temperature during December. The average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, in July is estimated at 86°F (30°C).

What is the average humidity in December in Marshalltown?

In December, the average relative humidity is 82%.

How much does it rain in Marshalltown in December?

In Marshalltown, in December, it is raining for 4.8 days, with typically 0.63" (16mm) of accumulated precipitation.

How much does it snow in Marshalltown in December?

In Marshalltown, in December, during 7.5 snowfall days, 1.14" (29mm) of snow is typically accumulated.

What is the month with the shortest days in Marshalltown?

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

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

The average day length in December in Marshalltown is 9h and 10min.

When is the sunrise / sunset in December in Marshalltown?

In December, on the first day of the month, sunrise is at 7:20 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:50 pm CST.

How many hours of sunshine does Marshalltown have in December?

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

What are the months with the lowest UV index in Marshalltown?

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

How high is the UV index in December in Marshalltown?

The average daily maximum UV index in December in Marshalltown, Iowa, is 2. A UV Index value of 2, and less, symbolizes a minimal hazard to health from exposure to the Sun's 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
Marshalltown, IA

Average temperature in December - Marshalltown, IA
  • Average high temperature in December: 32°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 (25.7°F).

  • Average low temperature in December: 21°F

The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (12.7°F).

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Average pressure in December
Marshalltown, IA

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

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

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Average wind speed in December
Marshalltown, IA

Average wind speed in December - Marshalltown, IA
  • Average wind speed in December: 10.3mph

The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).

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Average humidity in December
Marshalltown, IA

Average humidity in December - Marshalltown, IA
  • Average humidity in December: 82%

The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (72%).

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Average rainfall in December
Marshalltown, IA

Average rainfall in December - Marshalltown, IA
  • Average rainfall in December: 0.63"

The wettest month (with the highest rainfall) is June (2.56").
The driest month (with the least rainfall) is January (0.43").

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Average rainfall days in December
Marshalltown, IA

Average rainfall days in December - Marshalltown, IA
  • Average rainfall days in December: 4.8 days

The month with the highest number of rainy days is June (15.7 days).
The month with the least rainy days is February (2.8 days).

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Average snowfall in December
Marshalltown, IA

Average snowfall in December - Marshalltown, IA
  • Average snowfall in December: 1.14"

The month with the highest snowfall is January (1.93").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in December
Marshalltown, IA

Average snowfall days in December - Marshalltown, IA
  • Average snowfall days in December: 7.5 days

The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in December /
Average sunshine in December
Marshalltown, IA

Average daylight in December / Average sunshine in December - Marshalltown, 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: 3h and 54min).

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Average sunshine days in December
Marshalltown, IA

Average sunshine days in December - Marshalltown, IA
  • Average sunshine days in December: 20.6 days

The month with the most sunshine days is December (20.6 days).
The month with the least sunshine days is June (12.2 days).

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Average UV index in December
Marshalltown, IA

Average UV index in December - Marshalltown, IA
  • Average UV index in December: 2

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

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Average cloud cover in December
Marshalltown, IA

Average cloud cover in December - Marshalltown, IA
  • Average cloud cover in December: 54

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 30).

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Average visibility in December
Marshalltown, IA

Average visibility in December - Marshalltown, IA
  • Average visibility in December: 6mi

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

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Marshalltown, Iowa, USA

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