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December Weather in Oceanside, United States

Last updated: June 24, 2025

In December, the average temperature in Oceanside, United States hovers around 4°C (39°F). However, temperatures can dip as low as -10°C (13°F) or rise to a maximum of 17°C (64°F). Prepare for wet conditions, with 117 mm (4.6 in) of precipitation expected over 10 days and an average humidity level of 80%.

December Temperature in Oceanside

In December in Oceanside, the average temperature is 4°C (39°F). The maximum can reach 17°C (64°F), while the minimum can dip as low as -10°C (13°F). Travelers should be prepared for a wide range of temperatures and dress in layers to stay comfortable.

December Weather in Oceanside: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Oceanside, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Oceanside, December typically has an average temperature of 4°C (39°F), with highs reaching up to 17°C (64°F) and lows dropping to around -10°C (13°F).
JanFebMarAprMayJunJulAugSepOctNovDec343641516171777670614739
Data source: Temperature data for Oceanside generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Oceanside

In Oceanside in December, the total precipitation amount is 117 mm (4.6 in) recorded over a span of 10 days.

December Precipitation Trends in Oceanside

The chart displays monthly precipitation patterns in Oceanside, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Oceanside, December typically receives around 117 mm (4.6 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec7210698115117891421249113090117
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Oceanside

In Oceanside in December, humidity is 80%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making travel uncomfortable and requiring extra layers to stay warm while navigating through the misty streets.

December Average Humidity in Oceanside

This chart illustrates the average monthly humidity levels in Oceanside, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Oceanside is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%81%78%70%69%62%65%68%74%82%80%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Oceanside

In Oceanside in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Oceanside, you can visit Hourly UV Index in Oceanside.

Maximum UV Index Levels in Oceanside for December

The chart shows the monthly maximum UV Index (UVI) for Oceanside in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Oceanside typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356810101098642
Data source: Oceanside December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How December Weather in Oceanside Compares to Other Months

Weather in Oceanside varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Oceanside, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Oceanside, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (35°F)72 mm (2.8 inches)84%moderate
February Weather2°C (37°F)106 mm (4.2 inches)82%moderate
March Weather5°C (42°F)98 mm (3.9 inches)81%high
April Weather10°C (51°F)115 mm (4.5 inches)78%very high
May Weather16°C (61°F)117 mm (4.6 inches)69%very high
June Weather22°C (71°F)89 mm (3.5 inches)69%very high
July Weather25°C (78°F)142 mm (5.6 inches)62%very high
August Weather24°C (76°F)124 mm (4.9 inches)65%very high
September Weather21°C (70°F)91 mm (3.6 inches)68%very high
October Weather16°C (61°F)130 mm (5.1 inches)74%high
November Weather8°C (47°F)90 mm (3.5 inches)82%moderate
December Weather4°C (39°F)117 mm (4.6 inches)80%low

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