December weather forecast
Helena, MO

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Weather in December

The first month of the winter, December, is also an icy month in Helena, Missouri, with an average temperature ranging between max 38.3°F (3.5°C) and min 25°F (-3.9°C).

Temperature

In Helena, the average high-temperature in December decreases from a cool 50.9°F (10.5°C) in November to a wintry 38.3°F (3.5°C). Helena, during the month of December, experiences an average low-temperature of 25°F (-3.9°C).

Humidity

In Helena, Missouri, the average relative humidity in December is 76%.

Rainfall

In Helena, Missouri, during December, the rain falls for 5.5 days and regularly aggregates up to 1.1" (28mm) of precipitation. In Helena, during the entire year, the rain falls for 132.3 days and collects up to 27.28" (693mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Helena, during December, snow falls for 4.9 days and regularly aggregates up to 1.73" (44mm) of snow. Throughout the year, in Helena, there are 25.5 snowfall days, and 10.91" (277mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of December in Helena, Missouri, sunrise is at 7:21 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 5:03 pm CST.

Sunshine

In December, the average sunshine is 5.3h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for the average person.
Note: The maximum UV index, 2 during December, leads to the following recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is December cold in Helena?

In Helena, in December, the average high-temperature is 38.3°F (3.5°C), and the average low-temperature is 25°F (-3.9°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is evaluated at 93.2°F (34°C).

What is the average humidity in December in Helena?

In December, the average relative humidity in Helena, Missouri, is 76%.

How much does it rain in Helena in December?

In Helena, in December, during 5.5 rainfall days, 1.1" (28mm) of precipitation is typically accumulated.

How much does it snow in Helena in December?

In Helena, during December, snow falls for 4.9 days and regularly aggregates up to 1.73" (44mm) of snow.

What is the month with the shortest days in Helena?

The month with the shortest days in Helena, Missouri, is December, with an average of 9h and 24min of daylight.

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

In Helena, the average day length in December is 9h and 24min.

When is the sunrise / sunset in December in Helena?

On the first day of December in Helena, Missouri, sunrise is at 7:21 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 5:03 pm CST.

How long on average sun shines in December in Helena?

In Helena, the average sunshine duration in December is 5.3h.

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

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

What is the UV index reading in December in Helena?

In December, the average daily maximum UV index in Helena is 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability 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
Helena, MO

Average temperature in December - Helena, MO
  • Average high temperature in December: 38.3°F

The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (34.2°F).

  • Average low temperature in December: 25°F

The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).

Average pressure in December
Helena, MO

Average pressure in December - Helena, MO
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed in December
Helena, MO

Average wind speed in December - Helena, MO
  • Average wind speed in December: 9.2mph

The windiest months (with the highest average wind speed) are February and March (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).

Average humidity in December
Helena, MO

Average humidity in December - Helena, MO
  • Average humidity in December: 76%

The month with the highest relative humidity is June (79%).
The months with the lowest relative humidity are October and November (70%).

Average rainfall in December
Helena, MO

Average rainfall in December - Helena, MO
  • Average rainfall in December: 1.1"

The wettest month (with the highest rainfall) is May (4.02").
The driest months (with the least rainfall) are January and February (0.94").

Average rainfall days in December
Helena, MO

Average rainfall days in December - Helena, MO
  • Average rainfall days in December: 5.5 days

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (3.8 days).

Average snowfall in December
Helena, MO

Average snowfall in December - Helena, MO
  • Average snowfall in December: 1.73"

The month with the highest snowfall is January (3.43").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Helena, MO

Average snowfall days in December - Helena, MO
  • Average snowfall days in December: 4.9 days

The month with the highest number of snowfall days is February (7.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Helena, MO

Average daylight in December / Average sunshine in December - Helena, MO
  • 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 24min).

  • Average sunshine in December: 5h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).

Average sunshine days in December
Helena, MO

Average sunshine days in December - Helena, MO
  • Average sunshine days in December: 21 days

The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (10.8 days).

Average UV index in December
Helena, MO

Average UV index in December - Helena, MO
  • Average UV index in December: 2

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

Average cloud cover in December
Helena, MO

Average cloud cover in December - Helena, MO
  • Average cloud cover in December: 43

The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 27).

Average visibility in December
Helena, MO

Average visibility in December - Helena, MO
  • Average visibility in December: 6mi

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

Helena, Missouri, USA

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