December weather forecast
El Cajon, CA

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Weather in December

Finally, December brings with it the chill of the winter season, covering El Cajon in a cool atmosphere. As temperatures continue to fall, the climate becomes conducive for cozy indoor activities. With the year almost ending, long nights and condensed daylight hours dominate most part of the day. The weather during this month tends to be colder than October and November, heralding the arrival of a new year with a fresh and cool end. The average temperature ranges from 63.7°F (17.6°C) to 47.8°F (8.8°C) coupled with increased precipitation of 1.42" (36mm), emphasizes the city's transition into the grip of winter.

Temperature

El Cajon's coldest month, December, generally records average temperatures ranging from a high of 63.7°F (17.6°C) to a low of 47.8°F (8.8°C).

Humidity

In December, the average relative humidity is 59%.

Rainfall

In El Cajon, during December, the rain falls for 5.9 days and regularly aggregates up to 1.42" (36mm) of precipitation. Throughout the year, in El Cajon, California, there are 56.1 rainfall days, and 8.27" (210mm) of precipitation is accumulated.

Daylight

The month with the shortest days is December, with an average of 10h and 0min of daylight.
On the first day of the month, sunrise is at 6:32 am and sunset at 4:41 pm. On the last day of December, sunrise is at 6:50 am and sunset at 4:52 pm PST.

Sunshine

With an average of 6.7h of sunshine, December has the least sunshine of the year.

UV index

The months with the lowest UV index in El Cajon are January, February, November and December, with an average maximum UV index of 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 4 in December interprets into the following recommendations:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
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Frequently asked questions

What are the coldest months in El Cajon?

In El Cajon, California, the average lowest temperatures are observed in December, with a high of 63.7°F (17.6°C) and a low of 47.8°F (8.8°C).

What are December temperatures in El Cajon?

In December, the average high-temperature and low-temperature in El Cajon are 63.7°F (17.6°C) and 47.8°F (8.8°C) respectively. The average heat index (a.k.a. 'real feel', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in September is calculated to be 84.2°F (29°C).

What is the average humidity in December in El Cajon?

In December, the average relative humidity is 59%.

How much does it rain in El Cajon in December?

In December, in El Cajon, California, the rain falls for 5.9 days. Throughout December, 1.42" (36mm) of precipitation is accumulated.

What is the month with the shortest days in El Cajon?

With an average of 10h and 0min of daylight, December has the shortest days of the year in El Cajon, California.

What is the average length of the day in December in El Cajon?

In El Cajon, California, the average day length in December is 10h and 2min.

When are sunrise and sunset in December in El Cajon?

On the first day of December in El Cajon, California, sunrise is at 6:32 am and sunset at 4:41 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 4:52 pm PST.

What is the month with the least sunshine in El Cajon?

With an average of 6.7h of sunshine, December has the least sunshine of the year.

How many hours of sunshine does El Cajon have in December?

The average sunshine duration in December in El Cajon is 6.7h.

What is the month with the lowest UV index in El Cajon?

January, February, November and December, with an average maximum UV index of 4, are months with the lowest UV index in El Cajon.

What is the UV index reading in December in El Cajon?

The average daily maximum UV index in December is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
El Cajon, CA

Average temperature in December - El Cajon, CA
  • Average high temperature in December: 63.7°F

The warmest month (with the highest average high temperature) is August (83.8°F).
The month with the lowest average high temperature is December (63.7°F).

  • Average low temperature in December: 47.8°F

The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (47.8°F).

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Average pressure in December
El Cajon, CA

Average pressure in December - El Cajon, CA
  • Average pressure in December: 30.06"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are June and September (29.87"Hg).

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Average wind speed in December
El Cajon, CA

Average wind speed in December - El Cajon, CA
  • Average wind speed in December: 4.8mph

The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest month (with the lowest average wind speed) is October (4.3mph).

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Average humidity in December
El Cajon, CA

Average humidity in December - El Cajon, CA
  • Average humidity in December: 59%

The month with the highest relative humidity is May (66%).
The month with the lowest relative humidity is November (53%).

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Average rainfall in December
El Cajon, CA

Average rainfall in December - El Cajon, CA
  • Average rainfall in December: 1.42"

The wettest month (with the highest rainfall) is February (1.81").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days in December
El Cajon, CA

Average rainfall days in December - El Cajon, CA
  • Average rainfall days in December: 5.9 days

The month with the highest number of rainy days is March (7.7 days).
The month with the least rainy days is June (1.4 days).

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Average daylight in December /
Average sunshine in December
El Cajon, CA

Average daylight in December / Average sunshine in December - El Cajon, CA
  • Average daylight in December: 10h and 0min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in December: 6h and 4min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

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Average sunshine days in December
El Cajon, CA

Average sunshine days in December - El Cajon, CA
  • Average sunshine days in December: 24.7 days

The month with the most sunshine days is June (27.7 days).
The month with the least sunshine days is February (21.9 days).

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Average UV index in December
El Cajon, CA

Average UV index in December - El Cajon, CA
  • Average UV index in December: 4

The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).

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Average cloud cover in December
El Cajon, CA

Average cloud cover in December - El Cajon, CA
  • Average cloud cover in December: 23

The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 7).

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Average visibility in December
El Cajon, CA

Average visibility in December - El Cajon, 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).

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El Cajon, California, USA

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