December weather forecast
Lewistown, IL

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Weather in December

December, the first month of the winter in Lewistown, is also an icy month, with an average temperature varying between 26.4°F (-3.1°C) and 37°F (2.8°C).

Temperature

Lewistown's transition into December involves a shift in temperature, receding from a frosty 49.1°F (9.5°C) in November to a wintry 37°F (2.8°C). Lewistown experiences a nighttime temperature average of 26.4°F (-3.1°C) during December.

Humidity

The average relative humidity in December is 79%.

Rainfall

The month with the least rainfall in Lewistown is December, when the rain falls for 6.5 days and typically collects 0.94" (24mm) of precipitation.

Snowfall

Months with snowfall are January through April, October through December. In Lewistown, in December, during 5 snowfall days, 1.1" (28mm) of snow is typically accumulated. Throughout the year, there are 27.4 snowfall days, and 9.21" (234mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 7:05 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:44 pm CST.

Sunshine

The average sunshine in December is 4.5h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for average individuals.
Note: In December, a regular UV index of 2 translates into these guidelines:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Updated: Jun 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

In December, the average high-temperature and low-temperature are 37°F (2.8°C) and 26.4°F (-3.1°C) respectively. In August, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which combines air temperature and relative humidity, is estimated at 89.6°F (32°C).

What is the average humidity in December?

In Lewistown, the average relative humidity in December is 79%.

What is the driest month?

December is the month with the least rainfall. Rain falls for 6.5 days and accumulates 0.94" (24mm) of precipitation.

How much does it rain in December?

In Lewistown, in December, during 6.5 rainfall days, 0.94" (24mm) of precipitation is typically accumulated.

How many days does it snow in December?

In Lewistown, during December, snow falls for 5 days and regularly aggregates up to 1.1" (28mm) of snow.

What is the month with the shortest days?

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

How many hours of daylight does Lewistown have in December?

In Lewistown, the average day length in December is 9h and 21min.

When are sunrise and sunset in December in Lewistown?

In December, on the first day of the month, sunrise is at 7:05 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:44 pm CST.

How many hours of sunshine does Lewistown have in December?

In December, the average sunshine duration in Lewistown is 4.5h.

When is the lowest UV index?

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

What is the UV index reading in December?

In Lewistown, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability 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
Lewistown, IL

Average temperature in December - Lewistown, IL
  • Average high temperature in December: 37°F

The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in December: 26.4°F

The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (19.4°F).

Average pressure in December
Lewistown, IL

Average pressure in December - Lewistown, IL
  • 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 (29.91"Hg).

Average wind speed in December
Lewistown, IL

Average wind speed in December - Lewistown, IL
  • Average wind speed in December: 9.8mph

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.5mph).

Average humidity in December
Lewistown, IL

Average humidity in December - Lewistown, IL
  • Average humidity in December: 79%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

Average rainfall in December
Lewistown, IL

Average rainfall in December - Lewistown, IL
  • Average rainfall in December: 0.94"

The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is December (0.94").

Average rainfall days in December
Lewistown, IL

Average rainfall days in December - Lewistown, IL
  • Average rainfall days in December: 6.5 days

The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is February (4.7 days).

Average snowfall in December
Lewistown, IL

Average snowfall in December - Lewistown, IL
  • Average snowfall in December: 1.1"

The month with the highest snowfall is January (3.35").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Lewistown, IL

Average snowfall days in December - Lewistown, IL
  • Average snowfall days in December: 5 days

The month with the highest number of snowfall days is January (9.4 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
Lewistown, IL

Average daylight in December / Average sunshine in December - Lewistown, IL
  • 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: 4h and 3min

The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in December
Lewistown, IL

Average sunshine days in December - Lewistown, IL
  • Average sunshine days in December: 20.4 days

The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.1 days).

Average UV index in December
Lewistown, IL

Average UV index in December - Lewistown, IL
  • 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
Lewistown, IL

Average cloud cover in December - Lewistown, IL
  • Average cloud cover in December: 52

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

Average visibility in December
Lewistown, IL

Average visibility in December - Lewistown, IL
  • 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).

Lewistown, Illinois, USA

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