December weather forecast
Winnetka, CA

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Weather in December

December, the first month of the winter in Winnetka, is also an enjoyable month, with an average temperature fluctuating between 46.9°F (8.3°C) and 61.9°F (16.6°C).

Temperature

Winnetka's coldest temperatures are experienced in December, with average high temperatures of 61.9°F (16.6°C) and lows of 46.9°F (8.3°C).

Humidity

The average relative humidity in December is 53%.

Rainfall

In Winnetka, in December, during 4.7 rainfall days, 1.18" (30mm) of precipitation is typically accumulated. In Winnetka, during the entire year, the rain falls for 42.7 days and collects up to 6.46" (164mm) of precipitation.

Snowfall

December is the only month when snow falls. The month with the most snowfall days is December, when snow falls for 0.1 days.

Daylight

December has the shortest days of the year, with an average of 9h and 54min of daylight.
On the first day of December, sunrise is at 6:42 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 4:55 pm PST.

Sunshine

January, February and December, with an average of 6.8h of sunshine, are months with the least sunshine.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: A maximum daily UV index of 3 during December morphs into the following directions:
Heed the precautions - Suggestions to avoid sunburn are made. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.

Frequently asked questions

What part of the year is the coldest in Winnetka?

December is the month when Winnetka experiences its coldest temperatures, averaging a high of 61.9°F (16.6°C) and a low of 46.9°F (8.3°C).

What is the temperature in December?

The high-temperature in Winnetka during December is 61.9°F (16.6°C) and the low-temperature is 46.9°F (8.3°C). In September, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 84.2°F (29°C).

What is the average humidity in December?

In December, the average relative humidity is 53%.

How much does it rain in December?

In Winnetka, during December, the rain falls for 4.7 days and regularly aggregates up to 1.18" (30mm) of precipitation.

What is the snowiest month?

December has the most snowfall days of the year in Winnetka. Snow falls for 0.1 days.

When does it start snowing?

December is the first month it typically snows. Throughout December, there are 0.1 snowfall days.

What is the month with the shortest days?

With an average of 9h and 54min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

In Winnetka, the average day length in December is 9h and 55min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 6:42 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 4:55 pm PST.

What is the month with the least sunshine?

January, February and December, with an average of 6.8h of sunshine, are months with the least sunshine.

How long on average sun shines in December?

In Winnetka, California, the average sunshine duration in December is 6.8h.

When is the lowest UV index?

With an average maximum UV index of 3, December is the month with the lowest UV index.

How high is the UV index in December?

The average daily maximum UV index in December is 3. A UV Index of 3 to 5 symbolizes a moderate health threat 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
Winnetka, CA

Average temperature in December - Winnetka, CA
  • Average high temperature in December: 61.9°F

The warmest month (with the highest average high temperature) is August (85.6°F).
The month with the lowest average high temperature is December (61.9°F).

  • Average low temperature in December: 46.9°F

The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (46.9°F).

Average pressure in December
Winnetka, CA

Average pressure in December - Winnetka, CA
  • Average pressure in December: 30.08"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in December
Winnetka, CA

Average wind speed in December - Winnetka, CA
  • Average wind speed in December: 6.1mph

The windiest months (with the highest average wind speed) are January and December (6.1mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

Average humidity in December
Winnetka, CA

Average humidity in December - Winnetka, CA
  • Average humidity in December: 53%

The month with the highest relative humidity is June (59%).
The month with the lowest relative humidity is November (47%).

Average rainfall in December
Winnetka, CA

Average rainfall in December - Winnetka, CA
  • Average rainfall in December: 1.18"

The wettest month (with the highest rainfall) is February (1.22").
The driest month (with the least rainfall) is June (0.04").

Average rainfall days in December
Winnetka, CA

Average rainfall days in December - Winnetka, CA
  • Average rainfall days in December: 4.7 days

The month with the highest number of rainy days is March (6.5 days).
The month with the least rainy days is June (1.4 days).

Average snowfall days in December
Winnetka, CA

Average snowfall days in December - Winnetka, CA
  • Average snowfall days in December: 0.1 days

The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).

Average daylight in December /
Average sunshine in December
Winnetka, CA

Average daylight in December / Average sunshine in December - Winnetka, CA
  • Average daylight in December: 9h and 5min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in December: 6h and 5min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 48min).

Average sunshine days in December
Winnetka, CA

Average sunshine days in December - Winnetka, CA
  • Average sunshine days in December: 24.7 days

The months with the most sunshine days are August and October (27.3 days).
The month with the least sunshine days is February (22 days).

Average UV index in December
Winnetka, CA

Average UV index in December - Winnetka, CA
  • Average UV index in December: 3

The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in December
Winnetka, CA

Average cloud cover in December - Winnetka, CA
  • Average cloud cover in December: 21

The month with the most cloud cover is March (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 4).

Average visibility in December
Winnetka, CA

Average visibility in December - Winnetka, CA
  • 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).

Winnetka, California, USA

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