December weather forecast
Isla Vista, CA

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Weather in December

The first month of the winter, December, is still a mild month in Isla Vista, California, with an average temperature varying between 60.6°F (15.9°C) and 48.6°F (9.2°C).

Temperature

December, with an average high of 60.6°F (15.9°C) and a low of 48.6°F (9.2°C), signifies the coldest month of the year.

Humidity

In Isla Vista, the average relative humidity in December is 60%.

Rainfall

In December, the rain falls for 5.7 days. Throughout December, 1.34" (34mm) of precipitation is accumulated. Throughout the year, there are 43.7 rainfall days, and 7.68" (195mm) of precipitation is accumulated.

Ocean temperature

In December, the average ocean temperature is 58.5°F (14.7°C).
Note: Taking a dip in 58.5°F (14.7°C) can be perilous. Submersion in temperatures under 50°F (10°C) triggers severe cold shock accompanied by hyperventilation.

Daylight

The month with the shortest days is December, with an average of 9h and 54min of daylight.
On the first day of the month, sunrise is at 6:48 am and sunset at 4:49 pm. On the last day of December, in Isla Vista, California, sunrise is at 7:05 am and sunset at 4:59 pm PST.

Sunshine

In December, the average sunshine is 6.8h.

UV index

January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.
Note: In December, the average maximum UV index of 4 translates into the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Updated: Jul 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

December stands out as Isla Vista's coldest month, with an average high-temperature of 60.6°F (15.9°C) and a low-temperature of 48.6°F (9.2°C).

What are the temperatures in Isla Vista in December?

In Isla Vista, 60.6°F (15.9°C) is the average high-temperature and 48.6°F (9.2°C) is the average low-temperature during December.

What is the average humidity in December?

In December, the average relative humidity is 60%.

How much does it rain in December?

In Isla Vista, during December, the rain falls for 5.7 days and regularly aggregates up to 1.34" (34mm) of precipitation.

What is the water temperature in December?

In December, the average ocean temperature is 58.5°F (14.7°C). Swimming in 58.5°F (14.7°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days?

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

How many hours of daylight does Isla Vista have in December?

In Isla Vista, the average day length in December is 9h and 54min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 6:48 am and sunset at 4:49 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 4:59 pm PST.

How long on average sun shines in December?

In December, the average sunshine duration is 6.8h.

When is the lowest UV index in Isla Vista?

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

How high is the UV index in December in Isla Vista?

The average daily maximum UV index in December is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health from unprotected exposure to UV radiation.

Average temperature in December
Isla Vista, CA

Average temperature in December - Isla Vista, CA
  • Average high temperature in December: 60.6°F

The warmest month (with the highest average high temperature) is August (79.2°F).
The month with the lowest average high temperature is December (60.6°F).

  • Average low temperature in December: 48.6°F

The month with the highest average low temperature is August (62.1°F).
The coldest month (with the lowest average low temperature) is February (47.7°F).

Average pressure in December
Isla Vista, CA

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

The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).

Average wind speed in December
Isla Vista, CA

Average wind speed in December - Isla Vista, CA
  • Average wind speed in December: 6.6mph

The windiest month (with the highest average wind speed) is April (8.1mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).

Average humidity in December
Isla Vista, CA

Average humidity in December - Isla Vista, CA
  • Average humidity in December: 60%

The month with the highest relative humidity is March (64%).
The months with the lowest relative humidity are September, October and November (56%).

Average rainfall in December
Isla Vista, CA

Average rainfall in December - Isla Vista, CA
  • Average rainfall in December: 1.34"

The wettest month (with the highest rainfall) is January (1.57").
The driest months (with the least rainfall) are June and August (0.08").

Average rainfall days in December
Isla Vista, CA

Average rainfall days in December - Isla Vista, CA
  • Average rainfall days in December: 5.7 days

The month with the highest number of rainy days is March (7.3 days).
The month with the least rainy days is June (1.2 days).

Average sea temperature in December
Isla Vista, CA

Average sea temperature in December - Isla Vista, CA
  • Average sea temperature in December: 58.5°F

The best month for swimming (with the highest average sea temperature) is August (62.2°F).
The coldest month (with the lowest average sea temperature) is April (55.7°F).

Average daylight in December /
Average sunshine in December
Isla Vista, CA

Average daylight in December / Average sunshine in December - Isla Vista, 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 0min).
The month with the least sunshine is February (Average sunshine: 6h and 36min).

Average sunshine days in December
Isla Vista, CA

Average sunshine days in December - Isla Vista, CA
  • Average sunshine days in December: 24.6 days

The month with the most sunshine days is August (28 days).
The month with the least sunshine days is February (21.6 days).

Average UV index in December
Isla Vista, CA

Average UV index in December - Isla Vista, 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
Isla Vista, CA

Average cloud cover in December - Isla Vista, CA
  • Average cloud cover in December: 22

The month with the most cloud cover is March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).

Average visibility in December
Isla Vista, CA

Average visibility in December - Isla Vista, 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).

Isla Vista, California, USA

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