December weather forecast
Gillespie, IL

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Weather in December

The first month of the winter, December, is also an icy month in Gillespie, Illinois, with an average temperature varying between 29.1°F (-1.6°C) and 40.3°F (4.6°C).

Temperature

The transition into December is accompanied by a temperature decrease, with the average high-temperature shifting from a fresh 51.6°F (10.9°C) in November to an icy 40.3°F (4.6°C). An average nighttime temperature of 29.1°F (-1.6°C) is witnessed in Gillespie throughout December.

Humidity

The average relative humidity in December is 78%.

Rainfall

In Gillespie, in December, it is raining for 6.7 days, with typically 0.87" (22mm) of accumulated precipitation. In Gillespie, during the entire year, the rain falls for 121.4 days and collects up to 14.72" (374mm) of precipitation.

Snowfall

Months with snowfall are January through March, November and December. December is the month with the most snowfall. Snow falls for 3.8 days and accumulates 0.98" (25mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 30min of daylight.
On the first day of December, sunrise is at 7:00 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:46 pm CST.

Sunshine

In Gillespie, Illinois, the average sunshine in December is 4.8h.

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 minimal health vulnerability from unsafe exposure to UV radiation for average individuals.
Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.

Frequently asked questions

Is December cold?

December temperatures vary between a high-temperature of 40.3°F (4.6°C) and a low-temperature of 29.1°F (-1.6°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is calculated to be 91.4°F (33°C).

What is the average humidity in December?

In Gillespie, the average relative humidity in December is 78%.

How much does it rain in December?

In December, the rain falls for 6.7 days. Throughout December, 0.87" (22mm) of precipitation is accumulated.

What is the snowiest month?

The month with the most snowfall is December, when snow falls for 3.8 days and typically aggregates up to 0.98" (25mm) of snow.

How much does it snow in December?

In December, it is snowing for 3.8 days. Throughout December, 0.98" (25mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 30min of daylight, December has the shortest days of the year.

How many hours of daylight does Gillespie have in December?

In December, the average day length is 9h and 28min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:00 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:46 pm CST.

How long on average sun shines in December?

In December, the average sunshine duration is 4.8h.

What is the month with the lowest UV index in Gillespie?

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

What is the UV index reading in December in Gillespie?

In December, the average daily maximum UV index 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
Gillespie, IL

Average temperature in December - Gillespie, IL
  • Average high temperature in December: 40.3°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).

  • Average low temperature in December: 29.1°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

Average pressure in December
Gillespie, IL

Average pressure in December - Gillespie, IL
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Gillespie, IL

Average wind speed in December - Gillespie, IL
  • Average wind speed in December: 9.3mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

Average humidity in December
Gillespie, IL

Average humidity in December - Gillespie, IL
  • Average humidity in December: 78%

The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).

Average rainfall in December
Gillespie, IL

Average rainfall in December - Gillespie, IL
  • Average rainfall in December: 0.87"

The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").

Average rainfall days in December
Gillespie, IL

Average rainfall days in December - Gillespie, IL
  • Average rainfall days in December: 6.7 days

The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).

Average snowfall in December
Gillespie, IL

Average snowfall in December - Gillespie, IL
  • Average snowfall in December: 0.98"

The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Gillespie, IL

Average snowfall days in December - Gillespie, IL
  • Average snowfall days in December: 3.8 days

The month with the highest number of snowfall days is January (6.3 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
Gillespie, IL

Average daylight in December / Average sunshine in December - Gillespie, IL
  • Average daylight in December: 9h and 3min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in December: 4h and 5min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in December
Gillespie, IL

Average sunshine days in December - Gillespie, IL
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).

Average UV index in December
Gillespie, IL

Average UV index in December - Gillespie, 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
Gillespie, IL

Average cloud cover in December - Gillespie, IL
  • Average cloud cover in December: 50

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).

Average visibility in December
Gillespie, IL

Average visibility in December - Gillespie, 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).

Gillespie, Illinois, USA

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