December weather forecast
Rancho Santa Margarita, CA

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Weather in December

December, the first month of the winter in Rancho Santa Margarita, is still a refreshing month, with an average temperature ranging between min 49.8°F (9.9°C) and max 63°F (17.2°C).

Temperature

Rancho Santa Margarita reaches its lowest average temperatures in December, measuring 63°F (17.2°C) at the peak and 49.8°F (9.9°C) at the lowest.

Humidity

In Rancho Santa Margarita, the average relative humidity in December is 60%.

Rainfall

December is the month with the most rainfall. Rain falls for 6.7 days and accumulates 1.02" (26mm) of precipitation.

Daylight

The month with the shortest days is December, with an average of 10h and 0min of daylight.
On the first day of December, sunrise is at 6:37 am and sunset at 4:42 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 4:52 pm PST.

Sunshine

With an average of 6.6h of sunshine, December has the least sunshine of the year.

UV index

The months with the lowest UV index are January through March, 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 exposure to the Sun's UV rays for average individuals.
Note: In December, an average UV index of 4 transforms into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.

Frequently asked questions

What are the coldest months?

December is the month when Rancho Santa Margarita experiences its coldest temperatures, averaging a high of 63°F (17.2°C) and a low of 49.8°F (9.9°C).

What is the usual temperature for Rancho Santa Margarita in December?

In Rancho Santa Margarita, 63°F (17.2°C) is the average high-temperature and 49.8°F (9.9°C) is the average low-temperature during December. In August, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, is evaluated at 84.2°F (29°C).

What is the average humidity in December?

In Rancho Santa Margarita, the average relative humidity in December is 60%.

What is the wettest month?

December is the month with the most rainfall. Rain falls for 6.7 days and accumulates 1.02" (26mm) of precipitation.

How much does it rain in December?

In Rancho Santa Margarita, in December, during 6.7 rainfall days, 1.02" (26mm) of precipitation is typically accumulated.

What is the month with the shortest days in Rancho Santa Margarita?

December has the shortest days of the year, with an average of 10h and 0min of daylight.

How many hours of daylight does Rancho Santa Margarita have in December?

In Rancho Santa Margarita, the average day length in December is 9h and 58min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 6:37 am and sunset at 4:42 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 4:52 pm PST.

What is the month with the least sunshine?

The month with the least sunshine is December, with an average of 6.6h of sunshine.

How long on average sun shines in December?

In December, the average sunshine duration is 6.6h.

What is the month with the lowest UV index?

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 4.

How high is the UV index in December?

In December, the average daily maximum UV index in Rancho Santa Margarita is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Rancho Santa Margarita, CA

Average temperature in December - Rancho Santa Margarita, CA
  • Average high temperature in December: 63°F

The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (63°F).

  • Average low temperature in December: 49.8°F

The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is February (48.9°F).

Average pressure in December
Rancho Santa Margarita, CA

Average pressure in December - Rancho Santa Margarita, CA
  • Average pressure in December: 30.07"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.88"Hg).

Average wind speed in December
Rancho Santa Margarita, CA

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

The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).

Average humidity in December
Rancho Santa Margarita, CA

Average humidity in December - Rancho Santa Margarita, CA
  • Average humidity in December: 60%

The months with the highest relative humidity are May and June (70%).
The month with the lowest relative humidity is November (56%).

Average rainfall in December
Rancho Santa Margarita, CA

Average rainfall in December - Rancho Santa Margarita, CA
  • Average rainfall in December: 1.02"

The wettest month (with the highest rainfall) is December (1.02").
The driest month (with the least rainfall) is June (0.08").

Average rainfall days in December
Rancho Santa Margarita, CA

Average rainfall days in December - Rancho Santa Margarita, CA
  • Average rainfall days in December: 6.7 days

The month with the highest number of rainy days is March (8.6 days).
The month with the least rainy days is June (1.9 days).

Average daylight in December /
Average sunshine in December
Rancho Santa Margarita, CA

Average daylight in December / Average sunshine in December - Rancho Santa Margarita, CA
  • Average daylight in December: 10h and 0min

The month with the longest days is June (Average daylight: 14h and 24min).
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 August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).

Average sunshine days in December
Rancho Santa Margarita, CA

Average sunshine days in December - Rancho Santa Margarita, CA
  • Average sunshine days in December: 22.7 days

The month with the most sunshine days is January (24.3 days).
The month with the least sunshine days is February (19.8 days).

Average UV index in December
Rancho Santa Margarita, CA

Average UV index in December - Rancho Santa Margarita, 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, March, November and December (UV index 4).

Average cloud cover in December
Rancho Santa Margarita, CA

Average cloud cover in December - Rancho Santa Margarita, CA
  • Average cloud cover in December: 25

The months with the most cloud cover are March and December (Cloud cover 25).
The month with the least cloud cover is August (Cloud cover 7).

Average visibility in December
Rancho Santa Margarita, CA

Average visibility in December - Rancho Santa Margarita, 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).

Rancho Santa Margarita, California, USA

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