December weather forecast
Plano, IL

Share

Weather in December

December, the first month of the winter in Plano, is also an icy month, with temperature in the range of an average low of 23.9°F (-4.5°C) and an average high of 34.2°F (1.2°C).

Temperature

Plano's December weather comes with a decrease in average high-temperatures, moving from a chilly 45.9°F (7.7°C) in November to an icy 34.2°F (1.2°C). In December, Plano encounters an average low-temperature of 23.9°F (-4.5°C) during the night.

Humidity

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

Rainfall

In December, in Plano, the rain falls for 8.2 days. Throughout December, 1.85" (47mm) of precipitation is accumulated. In Plano, Illinois, during the entire year, the rain falls for 168.3 days and collects up to 35.47" (901mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In December, it is snowing for 10.2 days. Throughout December, 2.87" (73mm) of snow is accumulated. In Plano, during the entire year, snow falls for 47.1 days and aggregates up to 16.61" (422mm) of snow.

Daylight

December has the shortest days of the year in Plano, with an average of 9h and 12min of daylight.
On the first day of the month, sunrise is at 7:02 am and sunset at 4:24 pm. On the last day of December, in Plano, sunrise is at 7:20 am and sunset at 4:33 pm CST.

Sunshine

The average sunshine in December is 4.2h.

UV index

The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The UV index of 1 during December leads to these advisories:
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. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Plano in December?

The high-temperature, in December, in Plano, is 34.2°F (1.2°C), while the low-temperature averages to 23.9°F (-4.5°C). In July, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, is estimated at 86°F (30°C).

What is the average humidity in December in Plano?

The average relative humidity in December in Plano, Illinois, is 82%.

How many days does it rain in December in Plano?

In December, in Plano, the rain falls for 8.2 days. Throughout December, 1.85" (47mm) of precipitation is accumulated.

How many days does it snow in December in Plano?

In Plano, in December, during 10.2 snowfall days, 2.87" (73mm) of snow is typically accumulated.

What is the month with the shortest days in Plano?

The month with the shortest days in Plano, Illinois, is December, with an average of 9h and 12min of daylight.

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

In December, the average day length in Plano, Illinois, is 9h and 13min.

When are sunrise and sunset in December in Plano?

In December, on the first day of the month, sunrise is at 7:02 am and sunset at 4:24 pm. On the last day of the month, in Plano, Illinois, sunrise is at 7:20 am and sunset at 4:33 pm CST.

How long on average sun shines in December in Plano?

In Plano, Illinois, the average sunshine duration in December is 4.2h.

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

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

How high is the UV index in December in Plano?

In December, the average daily maximum UV index in Plano, Illinois, is 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe 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
Plano, IL

Average temperature in December - Plano, IL
  • Average high temperature in December: 34.2°F

The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (28.2°F).

  • Average low temperature in December: 23.9°F

The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).

Average pressure in December
Plano, IL

Average pressure in December - Plano, IL
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Plano, IL

Average wind speed in December - Plano, IL
  • Average wind speed in December: 9.1mph

The windiest months (with the highest average wind speed) are January and April (9.8mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in December
Plano, IL

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

The months with the highest relative humidity are July and August (84%).
The month with the lowest relative humidity is October (74%).

Average rainfall in December
Plano, IL

Average rainfall in December - Plano, IL
  • Average rainfall in December: 1.85"

The wettest month (with the highest rainfall) is May (4.88").
The driest month (with the least rainfall) is November (1.73").

Average rainfall days in December
Plano, IL

Average rainfall days in December - Plano, IL
  • Average rainfall days in December: 8.2 days

The month with the highest number of rainy days is July (20.3 days).
The month with the least rainy days is February (6 days).

Average snowfall in December
Plano, IL

Average snowfall in December - Plano, IL
  • Average snowfall in December: 2.87"

The month with the highest snowfall is January (4.88").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Plano, IL

Average snowfall days in December - Plano, IL
  • Average snowfall days in December: 10.2 days

The month with the highest number of snowfall days is January (13.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Plano, IL

Average daylight in December / Average sunshine in December - Plano, IL
  • 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 1min

The months with the most sunshine are June and August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in December
Plano, IL

Average sunshine days in December - Plano, IL
  • Average sunshine days in December: 14.5 days

The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is July (7.2 days).

Average UV index in December
Plano, IL

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

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in December
Plano, IL

Average cloud cover in December - Plano, IL
  • Average cloud cover in December: 57

The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 34).

Average visibility in December
Plano, IL

Average visibility in December - Plano, IL
  • Average visibility in December: 6mi

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

Plano, Illinois, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location