December weather forecast
Niwot, CO

Share

Weather in December

December, the first month of the winter in Niwot, is also a wintry month, with an average temperature ranging between max 39°F (3.9°C) and min 19.9°F (-6.7°C).

Temperature

During the coldest month, December, temperatures average a high of 39°F (3.9°C) and a low of 19.9°F (-6.7°C).

Humidity

In Niwot, Colorado, the average relative humidity in December is 63%.

Rainfall

In Niwot, during December, the rain falls for 4.7 days and regularly aggregates up to 0.39" (10mm) of precipitation. Throughout the year, there are 105.4 rainfall days, and 10.43" (265mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall. In Niwot, in December, snow falls for 6.1 days, with typically accumulated 3.03" (77mm) of snow. In Niwot, during the entire year, snow falls for 37.1 days and aggregates up to 26.73" (679mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of December, sunrise is at 7:04 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:45 pm MST.

Sunshine

In December, the average sunshine is 6.9h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: A maximum high UV index of 2 in December translates into the following recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Stay sun-safe with clothing that is both closely woven and worn loosely. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.

Frequently asked questions

What is the coldest time of year?

The coldest month in Niwot is December, with an average high-temperature of 39°F (3.9°C) and an average low-temperature of 19.9°F (-6.7°C).

How cold does it get in December?

In December, the average high-temperature and low-temperature in Niwot are 39°F (3.9°C) and 19.9°F (-6.7°C) respectively. The average heat index (a.k.a. 'real feel', 'feels like'), which combines air temperature and relative humidity, in August is appraised at 84.2°F (29°C).

What is the average humidity in December in Niwot?

The average relative humidity in December is 63%.

How many days does it rain in December?

In December, in Niwot, the rain falls for 4.7 days. Throughout December, 0.39" (10mm) of precipitation is accumulated.

How much does it snow in December?

In Niwot, during December, snow falls for 6.1 days and regularly aggregates up to 3.03" (77mm) of snow.

What is the month with the shortest days?

With an average of 9h and 24min of daylight, December has the shortest days of the year.

How many hours of daylight does Niwot have in December?

In December, the average day length is 9h and 23min.

When are sunrise and sunset in December in Niwot?

On the first day of December in Niwot, sunrise is at 7:04 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:45 pm MST.

How long on average sun shines in December?

In Niwot, the average sunshine duration in December is 6.9h.

What is the month with the lowest UV index?

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

What is the UV index intensity in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a minimal hazard to health 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
Niwot, CO

Average temperature in December - Niwot, CO
  • Average high temperature in December: 39°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is December (39°F).

  • Average low temperature in December: 19.9°F

The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is December (19.9°F).

Average pressure in December
Niwot, CO

Average pressure in December - Niwot, CO
  • Average pressure in December: 30.12"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are April and June (29.91"Hg).

Average wind speed in December
Niwot, CO

Average wind speed in December - Niwot, CO
  • Average wind speed in December: 5.7mph

The windiest months (with the highest average wind speed) are March and April (6.6mph).
The calmest months (with the lowest average wind speed) are August and September (5.6mph).

Average humidity in December
Niwot, CO

Average humidity in December - Niwot, CO
  • Average humidity in December: 63%

The month with the highest relative humidity is February (66%).
The month with the lowest relative humidity is August (42%).

Average rainfall in December
Niwot, CO

Average rainfall in December - Niwot, CO
  • Average rainfall in December: 0.39"

The wettest month (with the highest rainfall) is May (1.69").
The driest month (with the least rainfall) is January (0.35").

Average rainfall days in December
Niwot, CO

Average rainfall days in December - Niwot, CO
  • Average rainfall days in December: 4.7 days

The month with the highest number of rainy days is July (16 days).
The month with the least rainy days is January (3.5 days).

Average snowfall in December
Niwot, CO

Average snowfall in December - Niwot, CO
  • Average snowfall in December: 3.03"

The month with the highest snowfall is November (4.41").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Niwot, CO

Average snowfall days in December - Niwot, CO
  • Average snowfall days in December: 6.1 days

The month with the highest number of snowfall days is February (7.7 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Niwot, CO

Average daylight in December / Average sunshine in December - Niwot, CO
  • 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 24min).

  • Average sunshine in December: 6h and 5min

The month with the most sunshine is June (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).

Average sunshine days in December
Niwot, CO

Average sunshine days in December - Niwot, CO
  • Average sunshine days in December: 22.5 days

The month with the most sunshine days is January (23.4 days).
The month with the least sunshine days is July (9.3 days).

Average UV index in December
Niwot, CO

Average UV index in December - Niwot, CO
  • Average UV index in December: 2

The months with the highest UV index are 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
Niwot, CO

Average cloud cover in December - Niwot, CO
  • Average cloud cover in December: 23

The months with the most cloud cover are April and May (Cloud cover 26).
The months with the least cloud cover are June and September (Cloud cover 16).

Average visibility in December
Niwot, CO

Average visibility in December - Niwot, CO
  • 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).

Niwot, Colorado, USA

Weather forecast for your location

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