December weather forecast and climate
Rancho Bernardo, CA

Weather in December

The first month of the winter, December, is also an enjoyable month in Rancho Bernardo, California, with average temperature ranging between max 63.9°F (17.7°C) and min 47.7°F (8.7°C).

Temperature

With an average high-temperature of 63.9°F (17.7°C) and an average low-temperature of 47.7°F (8.7°C), December is the coldest month.

Humidity

In December, the average relative humidity is 59%.

Rainfall

In Rancho Bernardo, California, in December, during 6.1 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. Throughout the year, in Rancho Bernardo, there are 54.7 rainfall days, and 8.15" (207mm) of precipitation is accumulated.

Daylight

December has the shortest days of the year, with an average of 10h of daylight.

Sunshine

Months with the least sunshine in Rancho Bernardo are January and December, with an average of 6.7h of sunshine.

UV index

Months with the lowest UV index in Rancho Bernardo, California, are January, February, November and December, with an average maximum UV index of 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from the exposure to the Sun's UV radiation for the ordinary person.
Note: The average daily UV index of 4 transform into the following instructions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the coldest month in Rancho Bernardo?

December is the coldest month, with an average high-temperature of 63.9°F (17.7°C) and an average low-temperature of 47.7°F (8.7°C).

What is the temperature in December in Rancho Bernardo?

In Rancho Bernardo, California, in December, the average high-temperature is 63.9°F (17.7°C), and the average low-temperature is 47.7°F (8.7°C).

What is the average humidity in December in Rancho Bernardo?

In Rancho Bernardo, the average relative humidity in December is 59%.

How many days does it rain in December in Rancho Bernardo?

In Rancho Bernardo, California, in December, during 6.1 rainfall days, 1.46" (37mm) of precipitation is typically accumulated.

What is the month with the shortest days in Rancho Bernardo?

The month with the shortest days in Rancho Bernardo, California, is December, with an average of 10h of daylight.

How many hours of daylight does Rancho Bernardo have in December?

In December, the average length of the day is 10h.

What is the month with the least sunshine in Rancho Bernardo?

January and December, with an average of 6.7h of sunshine, are months with the least sunshine in Rancho Bernardo.

How many hours of sunshine does Rancho Bernardo have in December?

In Rancho Bernardo, California, the average sunshine in December is 6.7h.

What are the months with the lowest UV index in Rancho Bernardo?

Months with the lowest UV index in Rancho Bernardo are January, February, November and December, with an average maximum UV index of 4.

What is the UV index reading in December in Rancho Bernardo?

In December, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unprotected exposure to the UV radiation.

Average temperature in December
Rancho Bernardo, CA

Average temperature in December - Rancho Bernardo, CA
  • Average high temperature in December: 63.9°F

The warmest month (with the highest average high temperature) is August (84.2°F).
The month with the lowest average high temperature is December (63.9°F).

  • Average low temperature in December: 47.7°F

The month with the highest average low temperature is August (64.4°F).
The coldest month (with the lowest average low temperature) is February (47.1°F).

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Average pressure in December
Rancho Bernardo, CA

Average pressure in December - Rancho Bernardo, CA
  • Average pressure in December: 30.06"

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

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Average wind speed in December
Rancho Bernardo, CA

Average wind speed in December - Rancho Bernardo, CA
  • Average wind speed in December: 5mph

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

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Average humidity in December
Rancho Bernardo, CA

Average humidity in December - Rancho Bernardo, CA
  • Average humidity in December: 59%

The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (54%).

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Average rainfall in December
Rancho Bernardo, CA

Average rainfall in December - Rancho Bernardo, CA
  • Average rainfall in December: 1.46"

The wettest month (with the highest rainfall) is February (1.61").
The driest month (with the least rainfall) is June (0.08").

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Average rainfall days in December
Rancho Bernardo, CA

Average rainfall days in December - Rancho Bernardo, CA
  • Average rainfall days in December: 6.1 days

The month with the highest number of rainy days is March (7.2 days).
The month with the least rainy days is June (1.6 days).

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Average daylight in December /
Average sunshine in December
Rancho Bernardo, CA

Average daylight in December / Average sunshine in December - Rancho Bernardo, CA
  • Average daylight in December: 10h

The month with the longest days is June (Average daylight: 14.3h).
The month with the shortest days is December (Average daylight: 10h).

  • Average sunshine in December: 6.7h

The month with the most sunshine is July (Average sunshine: 12h).
Months with the least sunshine are January and December (Average sunshine: 6.7).

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Average sunshine days in December
Rancho Bernardo, CA

Average sunshine days in December - Rancho Bernardo, CA
  • Average sunshine days in December: 23.5 days

The month with the most sunshine days is June (27 days).
The month with the least sunshine days is February (21.2 days).

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Average UV index in December
Rancho Bernardo, CA

Average UV index in December - Rancho Bernardo, CA
  • Average UV index in December: 4

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

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Average cloud cover in December
Rancho Bernardo, CA

Average cloud cover in December - Rancho Bernardo, CA
  • Average cloud cover in December: 23

The month with the most cloud cover is March (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 7).

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Average visibility in December
Rancho Bernardo, CA

Average visibility in December - Rancho Bernardo, CA
  • Average visibility in December: 6mi

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

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