December weather forecast
Illmo, MO

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Weather in December

The first month of the winter, December, is also a frosty month in Illmo, Missouri, with an average temperature ranging between min 33.1°F (0.6°C) and max 45.5°F (7.5°C).

Temperature

December shows a mild decline in the average high-temperature, falling from November's cool 54.7°F (12.6°C) to a frosty 45.5°F (7.5°C). In Illmo, December's nights observe an average temperature dip to a cold 33.1°F (0.6°C).

Humidity

The average relative humidity in December is 77%.

Rainfall

In Illmo, during December, the rain falls for 10.8 days and regularly aggregates up to 2.44" (62mm) of precipitation. Throughout the year, there are 158.6 rainfall days, and 35.59" (904mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through April, October through December. In December, it is snowing for 1.6 days. Throughout December, 0.67" (17mm) of snow is accumulated. Throughout the year, in Illmo, there are 11.2 snowfall days, and 4.92" (125mm) of snow is accumulated.

Daylight

With an average of 9h and 42min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 6:53 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:50 pm CST.

Sunshine

In Illmo, the average sunshine in December is 5h.

UV index

January, February and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 2 during December translates into the following directions:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Opt for tightly woven and loose clothing to enhance protection from the Sun. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Updated: Jul 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are December temperatures in Illmo?

The average high-temperature and low-temperature during December are 45.5°F (7.5°C) and 33.1°F (0.6°C) respectively. The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines relative humidity and air temperature, in September is computed to be 86°F (30°C).

What is the average humidity in December?

In Illmo, the average relative humidity in December is 77%.

How much does it rain in December?

In Illmo, in December, it is raining for 10.8 days, with typically 2.44" (62mm) of accumulated precipitation.

How much does it snow in December?

In Illmo, during December, snow falls for 1.6 days and regularly aggregates up to 0.67" (17mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 42min of daylight.

How many hours of daylight does Illmo have in December?

In December, the average day length is 9h and 39min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:53 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:50 pm CST.

How long on average sun shines in December?

In December, the average sunshine duration is 5h.

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

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

What is the UV index reading in December in Illmo?

In Illmo, the average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health risk from 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
Illmo, MO

Average temperature in December - Illmo, MO
  • Average high temperature in December: 45.5°F

The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (41°F).

  • Average low temperature in December: 33.1°F

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).

Average pressure in December
Illmo, MO

Average pressure in December - Illmo, MO
  • Average pressure in December: 30.14"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in December
Illmo, MO

Average wind speed in December - Illmo, MO
  • Average wind speed in December: 8.6mph

The windiest months (with the highest average wind speed) are January and February (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).

Average humidity in December
Illmo, MO

Average humidity in December - Illmo, MO
  • Average humidity in December: 77%

The months with the highest relative humidity are March and May (78%).
The month with the lowest relative humidity is October (69%).

Average rainfall in December
Illmo, MO

Average rainfall in December - Illmo, MO
  • Average rainfall in December: 2.44"

The wettest month (with the highest rainfall) is April (4.33").
The driest month (with the least rainfall) is September (1.5").

Average rainfall days in December
Illmo, MO

Average rainfall days in December - Illmo, MO
  • Average rainfall days in December: 10.8 days

The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (9.8 days).

Average snowfall in December
Illmo, MO

Average snowfall in December - Illmo, MO
  • Average snowfall in December: 0.67"

The month with the highest snowfall is February (2.17").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Illmo, MO

Average snowfall days in December - Illmo, MO
  • Average snowfall days in December: 1.6 days

The month with the highest number of snowfall days is January (3.7 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
Illmo, MO

Average daylight in December / Average sunshine in December - Illmo, MO
  • Average daylight in December: 9h and 4min

The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in December: 5h and 0min

The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in December
Illmo, MO

Average sunshine days in December - Illmo, MO
  • Average sunshine days in December: 18.1 days

The month with the most sunshine days is October (18.6 days).
The month with the least sunshine days is July (11.9 days).

Average UV index in December
Illmo, MO

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

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

Average cloud cover in December
Illmo, MO

Average cloud cover in December - Illmo, MO
  • Average cloud cover in December: 46

The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are June, August and September (Cloud cover 27).

Average visibility in December
Illmo, MO

Average visibility in December - Illmo, 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).

Illmo, Missouri, USA

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