December weather forecast
Downers Grove, IA

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Weather in December

The first month of the winter, December, is still a freezing cold month in Downers Grove, Iowa, with an average temperature varying between 21.4°F (-5.9°C) and 31.8°F (-0.1°C).

Temperature

In Downers Grove, the beginning of December is marked by a lowered average high-temperature, shifting from November's frosty 44.6°F (7°C) to a freezing cold 31.8°F (-0.1°C). Downers Grove experiences an average low-temperature reading of 21.4°F (-5.9°C) throughout December.

Humidity

In December, the average relative humidity is 82%.

Rainfall

In Downers Grove, during December, the rain falls for 7.7 days and regularly aggregates up to 1.42" (36mm) of precipitation. In Downers Grove, Iowa, during the entire year, the rain falls for 142.5 days and collects up to 28.27" (718mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In Downers Grove, during December, snow falls for 9.4 days and regularly aggregates up to 3.07" (78mm) of snow. Throughout the year, there are 43.2 snowfall days, and 17.17" (436mm) of snow is accumulated.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:15 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 4:43 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 unsafe exposure to UV radiation for ordinary individuals.
Note: The UV index of 1 in December translates into these instructions:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. When the Sun is at its strongest around midday, find shade and limit exposure. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Updated: Aug 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

December temperatures vary between a high-temperature of 31.8°F (-0.1°C) and a low-temperature of 21.4°F (-5.9°C).

What is the average humidity in December?

The average relative humidity in December is 82%.

How much does it rain in December?

In Downers Grove, during December, the rain falls for 7.7 days and regularly aggregates up to 1.42" (36mm) of precipitation.

How much does it snow in Downers Grove in December?

In December, it is snowing for 9.4 days. Throughout December, 3.07" (78mm) of snow is accumulated.

What is the month with the shortest days in Downers Grove?

December has the shortest days of the year, with an average of 9h and 12min of daylight.

How many hours of daylight does Downers Grove have in December?

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

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:15 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 4:43 pm CST.

How many hours of sunshine does Downers Grove have in December?

The average sunshine duration in December is 4.2h.

What are the months with the lowest UV index?

The 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 Downers Grove, the average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health threat 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
Downers Grove, IA

Average temperature in December - Downers Grove, IA
  • Average high temperature in December: 31.8°F

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.2°F).

  • Average low temperature in December: 21.4°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).

Average pressure in December
Downers Grove, IA

Average pressure in December - Downers Grove, IA
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in December
Downers Grove, IA

Average wind speed in December - Downers Grove, IA
  • Average wind speed in December: 10mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).

Average humidity in December
Downers Grove, IA

Average humidity in December - Downers Grove, IA
  • Average humidity in December: 82%

The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is October (74%).

Average rainfall in December
Downers Grove, IA

Average rainfall in December - Downers Grove, IA
  • Average rainfall in December: 1.42"

The wettest month (with the highest rainfall) is May (4.25").
The driest months (with the least rainfall) are January and February (1.26").

Average rainfall days in December
Downers Grove, IA

Average rainfall days in December - Downers Grove, IA
  • Average rainfall days in December: 7.7 days

The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (5.2 days).

Average snowfall in December
Downers Grove, IA

Average snowfall in December - Downers Grove, IA
  • Average snowfall in December: 3.07"

The month with the highest snowfall is January (5.04").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Downers Grove, IA

Average snowfall days in December - Downers Grove, IA
  • Average snowfall days in December: 9.4 days

The month with the highest number of snowfall days is January (12.1 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
Downers Grove, IA

Average daylight in December / Average sunshine in December - Downers Grove, IA
  • 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 July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in December
Downers Grove, IA

Average sunshine days in December - Downers Grove, IA
  • Average sunshine days in December: 16.7 days

The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).

Average UV index in December
Downers Grove, IA

Average UV index in December - Downers Grove, IA
  • 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
Downers Grove, IA

Average cloud cover in December - Downers Grove, IA
  • Average cloud cover in December: 57

The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in December
Downers Grove, IA

Average visibility in December - Downers Grove, IA
  • Average visibility in December: 6mi

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

Downers Grove, Iowa, USA

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