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December Weather in Union City, United States

Last updated: June 24, 2025

In Union City, United States, the average temperature in December hovers around 9°C (49°F). However, temperatures can vary significantly, with a chilly minimum of -6°C (22°F) and a warm maximum reaching 24°C (76°F). Expect 136 mm (5.3 in) of precipitation spread over 12 days, and prepare for a high average humidity of 89%.

December Temperature in Union City

In December in Union City, the average temperature is 9°C (49°F), with maximums reaching 24°C (76°F) and minimums dropping as low as -6°C (22°F). Travelers should be prepared for a wide range of temperatures during this time.

December Weather in Union City: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Union City, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Union City, December typically has an average temperature of 9°C (49°F), with highs reaching up to 24°C (76°F) and lows dropping to around -6°C (22°F).
JanFebMarAprMayJunJulAugSepOctNovDec465257627177807975665349
Data source: Temperature data for Union City 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 Union City

In Union City in December, the precipitation amount is 136 mm (5.3 in) over the course of 12 days.

December Precipitation Trends in Union City

The chart displays monthly precipitation patterns in Union City, 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 Union City, December typically receives around 136 mm (5.3 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec1011341171169111511113711111379136
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Union City

In Union City in December, humidity is 89%. With an average temperature of 9°C (49°F), this humidity feels like a persistent dampness that clings to your clothes and skin, making it challenging to stay comfortable while traveling.

December Average Humidity in Union City

This chart illustrates the average monthly humidity levels in Union City, 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 Union City is approximately 89%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%84%83%81%81%81%83%81%82%78%86%89%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Union City

In Union City in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Union City for better planning.

Maximum UV Index Levels in Union City for December

The chart shows the monthly maximum UV Index (UVI) for Union City 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 Union City typically reaches 4, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec47811111111109864
Data source: Union City 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 Union City Compares to Other Months

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

This table compares monthly weather conditions in Union City, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather8°C (46°F)101 mm (4.0 inches)86%moderate
February Weather11°C (52°F)134 mm (5.3 inches)84%high
March Weather14°C (57°F)117 mm (4.6 inches)83%very high
April Weather17°C (63°F)116 mm (4.6 inches)81%extreme
May Weather22°C (71°F)90 mm (3.6 inches)81%extreme
June Weather25°C (77°F)115 mm (4.5 inches)81%extreme
July Weather26°C (80°F)111 mm (4.4 inches)83%extreme
August Weather26°C (79°F)137 mm (5.4 inches)81%very high
September Weather24°C (75°F)111 mm (4.4 inches)82%very high
October Weather19°C (67°F)113 mm (4.4 inches)78%very high
November Weather11°C (53°F)79 mm (3.1 inches)86%high
December Weather9°C (49°F)136 mm (5.3 inches)89%moderate

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