Naperville
Illinois, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Naperville, IL

The scenic view of a covered bridge over a river along the famous Naperville Riverwalk in Naperville, Illinois, reflections in the below water
The scenic view of a covered bridge over a river along the famous Naperville Riverwalk in Naperville, Illinois, reflections in the below water
The first month of the winter, December, is still a cold month in Naperville, Illinois, with average temperature ranging between max 34.3°F (1.3°C) and min 24.4°F (-4.2°C).

Temperature

In December, the average high-temperature drops, from a frosty 45.9°F (7.7°C) in November, to a cold 34.3°F (1.3°C). In December, the average low-temperature is 24.4°F (-4.2°C).

Humidity

In Naperville, the average relative humidity in December is 82%.

Rainfall

The month with the least rainfall in Naperville is December when the rain falls for 6.4 days and typically collects 0.71" (18mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall in Naperville. In Naperville, snow falls for 8.1 days, with typically accumulated 1.02" (26mm) of snow. Throughout the year, in Naperville, there are 38.7 snowfall days, and 6.93" (176mm) of snow is accumulated.

Daylight

With an average of 9.2h of daylight, December has the shortest days of the year in Naperville.

Sunshine

In Naperville, the average sunshine is 4.2h.

UV index

Months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: The average daily UV index of 1 in December transform into the following instructions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in December in Naperville?

The average high-temperature, in December, in Naperville, Illinois, is 34.3°F (1.3°C), while the average low-temperature is 24.4°F (-4.2°C).

What is the average humidity in December in Naperville?

In Naperville, the average relative humidity in December is 82%.

How many days does it rain in December in Naperville?

In Naperville, during December, the rain falls for 6.4 days and regularly aggregates up to 0.71" (18mm) of precipitation.

What is the driest month in Naperville?

The month with the least rainfall in Naperville is December when the rain falls for 6.4 days and typically collects 0.71" (18mm) of precipitation.

How much does it snow in Naperville in December?

In December, it is snowing for 8.1 days. Throughout December, 1.02" (26mm) of snow is accumulated.

What is the month with the shortest days in Naperville?

With an average of 9.2h of daylight, December has the shortest days of the year in Naperville.

How many hours of daylight does Naperville have in December?

In Naperville, the average length of the day in December is 9.2h.

How long on average sun shines in December in Naperville?

In December, the average sunshine is 4.2h.

When is the lowest UV index in Naperville?

Months with the lowest UV index are January and December, with an average maximum UV index of 1.

What is the UV index reading in December in Naperville?

In Naperville, Illinois, the average daily maximum UV index in December is 1. A UV Index value of 2, and less, symbolizes a low health threat from unprotected exposure to the UV radiation.
Average temperature in December - Naperville, IL
  • Average high temperature in December: 1.3°C

The warmest month (with the highest average high temperature) is July (27.6°C).
The month with the lowest average high temperature is January (-2°C).

  • Average low temperature in December: -4.2°C

The month with the highest average low temperature is July (18.4°C).
The coldest month (with the lowest average low temperature) is January (-8.3°C).

Average humidity in December - Naperville, IL
  • Average humidity in December: 82%

Months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (73%).

Average rainfall in December - Naperville, IL
  • Average rainfall in December: 18mm

The wettest month (with the highest rainfall) is May (53mm).
The driest month (with the lowest rainfall) is December (18mm).

Average rainfall days in December - Naperville, IL
  • Average rainfall days in December: 6.4 days

The month with the highest number of rainy days is July (17.3 days).
The month with the lowest number of rainy days is February (4.4 days).

Average snowfall in December - Naperville, IL
  • Average snowfall in December: 26mm

The month with the highest snowfall is January (47mm).
Months with the lowest snowfall are May, June, July, August and September (0mm).

Average snowfall days in December - Naperville, IL
  • Average snowfall days in December: 8.1 days

The month with the highest number of snowfall days is January (11.1 days).
Months with the lowest number of snowfall days are June, July, August and September (0 days).

Average daylight in December / Average sunshine in December - Naperville, IL
  • Average daylight in December: 9.2h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in December: 4.2h

Months with most sunshine are July and August (Average sunshine: 10h).
The month with least sunshine is January (Average sunshine: 3.8h).

Average UV index in December - Naperville, IL
  • Average UV index in December: 1

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January and December (UV index 1).