December weather forecast
Arroyo Grande, CA

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Weather in December

December, the first month of the winter in Arroyo Grande, is still a refreshing month, with an average temperature fluctuating between 46.8°F (8.2°C) and 61.2°F (16.2°C).

Temperature

Arroyo Grande, California, witnesses the coldest weather in December, with temperatures averaging a high of 61.2°F (16.2°C) and a low of 46.8°F (8.2°C).

Humidity

In December, the average relative humidity in Arroyo Grande is 63%.

Rainfall

In December, in Arroyo Grande, the rain falls for 6.4 days. Throughout December, 1.02" (26mm) of precipitation is accumulated. Throughout the year, in Arroyo Grande, there are 47.6 rainfall days, and 6.93" (176mm) of precipitation is accumulated.

Daylight

With an average of 9h and 48min of daylight, December has the shortest days of the year.
On the first day of December in Arroyo Grande, California, sunrise is at 6:52 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 5:00 pm PST.

Sunshine

February and December, with an average of 6.5h of sunshine, are months with the least sunshine.

UV index

January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index in Arroyo Grande. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The UV index of 4 during December leads to these advisories:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
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Frequently asked questions

What month is the coldest in Arroyo Grande?

In Arroyo Grande, California, the lowest temperatures are generally noted in December, averaging a high of 61.2°F (16.2°C) and a low of 46.8°F (8.2°C).

What is the average December temperature in Arroyo Grande?

December temperatures vary between a high-temperature of 61.2°F (16.2°C) and a low-temperature of 46.8°F (8.2°C).

What is the average humidity in December in Arroyo Grande?

The average relative humidity in December in Arroyo Grande, California, is 63%.

How much does it rain in Arroyo Grande in December?

In Arroyo Grande, during December, the rain falls for 6.4 days and regularly aggregates up to 1.02" (26mm) of precipitation.

What is the month with the shortest days in Arroyo Grande?

The month with the shortest days in Arroyo Grande is December, with an average of 9h and 48min of daylight.

What is the average length of the day in December in Arroyo Grande?

In Arroyo Grande, the average day length in December is 9h and 50min.

When is the sunrise / sunset in December in Arroyo Grande?

On the first day of December in Arroyo Grande, sunrise is at 6:52 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 5:00 pm PST.

What are the months with the least sunshine in Arroyo Grande?

The months with the least sunshine in Arroyo Grande are February and December, with an average of 6.5h of sunshine.

How many hours of sunshine does Arroyo Grande have in December?

In Arroyo Grande, the average sunshine duration in December is 6.5h.

When is the lowest UV index in Arroyo Grande?

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

What is the UV index reading in December in Arroyo Grande?

In December, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from 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
Arroyo Grande, CA

Average temperature in December - Arroyo Grande, CA
  • Average high temperature in December: 61.2°F

The warmest month (with the highest average high temperature) is September (79.5°F).
The month with the lowest average high temperature is December (61.2°F).

  • Average low temperature in December: 46.8°F

The month with the highest average low temperature is September (59.9°F).
The coldest month (with the lowest average low temperature) is February (46°F).

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Average pressure in December
Arroyo Grande, CA

Average pressure in December - Arroyo Grande, CA
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).

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Average wind speed in December
Arroyo Grande, CA

Average wind speed in December - Arroyo Grande, CA
  • Average wind speed in December: 6.5mph

The windiest months (with the highest average wind speed) are April and May (7.3mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

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Average humidity in December
Arroyo Grande, CA

Average humidity in December - Arroyo Grande, CA
  • Average humidity in December: 63%

The month with the highest relative humidity is March (68%).
The month with the lowest relative humidity is October (58%).

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Average rainfall in December
Arroyo Grande, CA

Average rainfall in December - Arroyo Grande, CA
  • Average rainfall in December: 1.02"

The wettest month (with the highest rainfall) is March (1.61").
The driest months (with the least rainfall) are June and August (0.04").

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Average rainfall days in December
Arroyo Grande, CA

Average rainfall days in December - Arroyo Grande, CA
  • Average rainfall days in December: 6.4 days

The month with the highest number of rainy days is March (8.4 days).
The month with the least rainy days is August (0.8 days).

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Average daylight in December /
Average sunshine in December
Arroyo Grande, CA

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

The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • Average sunshine in December: 6h and 3min

The months with the most sunshine are June, July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are February and December (Average sunshine: 6h and 30min).

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Average sunshine days in December
Arroyo Grande, CA

Average sunshine days in December - Arroyo Grande, CA
  • Average sunshine days in December: 24 days

The month with the most sunshine days is August (29.6 days).
The month with the least sunshine days is February (21 days).

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Average UV index in December
Arroyo Grande, CA

Average UV index in December - Arroyo Grande, CA
  • Average UV index in December: 4

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

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Average cloud cover in December
Arroyo Grande, CA

Average cloud cover in December - Arroyo Grande, CA
  • Average cloud cover in December: 25

The month with the most cloud cover is March (Cloud cover 27).
The month with the least cloud cover is August (Cloud cover 6).

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Average visibility in December
Arroyo Grande, CA

Average visibility in December - Arroyo Grande, 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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Arroyo Grande, California, USA

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