December Weather in Delta, United States

Last updated: June 24, 2025

In December, the average temperature in Delta, United States hovers around 4°C (39°F). Expect a diverse range of weather, as temperatures can dip to a frigid -11°C (12°F) or rise to a pleasant 18°C (65°F). Prepare for some rain, with an average precipitation of 98 mm (3.9 in) spread across 9 days. Additionally, the average humidity sits at a high 84%, making for a chilly yet atmospheric experience.

December Temperature in Delta

In December in Delta, the average temperature is 4°C (39°F), with maximums reaching 18°C (65°F) and minimums dropping as low as -11°C (12°F). It's advisable to pack warm clothing while also being prepared for occasional milder days during your travels.

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

The chart illustrates December temperature patterns in Delta, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Delta, December typically has an average temperature of 4°C (39°F), with highs reaching up to 18°C (65°F) and lows dropping to around -11°C (12°F).

Data source: Temperature data for Delta generated using information from the Copernicus Climate Change Service.

December Precipitation in Delta

In Delta in December, the precipitation amount is 98 mm (3.9 in) spread over a duration of 9 days.

December Precipitation Trends in Delta

The chart displays monthly precipitation patterns in Delta, 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 Delta, December typically receives around 98 mm (3.9 inches) of precipitation spread over approximately 9 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Delta

In Delta in December, humidity is 84%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making outdoor excursions uncomfortable and demanding more layers than you anticipate while traveling.

December Average Humidity in Delta

This chart illustrates the average monthly humidity levels in Delta, 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 Delta is approximately 84%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Delta

In Delta in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Delta, you can check the information here.

Maximum UV Index Levels in Delta for December

The chart shows the monthly maximum UV Index (UVI) for Delta 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 Delta typically reaches 3, which falls under the moderate exposure category.

Data source: Delta 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 Delta Compares to Other Months

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

This table compares monthly weather conditions in Delta, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (35°F)	61 mm (2.4 inches)	84%	moderate
February Weather	3°C (38°F)	97 mm (3.8 inches)	83%	moderate
March Weather	6°C (44°F)	100 mm (3.9 inches)	83%	high
April Weather	12°C (54°F)	100 mm (3.9 inches)	81%	very high
May Weather	18°C (64°F)	140 mm (5.5 inches)	78%	very high
June Weather	23°C (73°F)	108 mm (4.3 inches)	79%	very high
July Weather	26°C (79°F)	150 mm (5.9 inches)	74%	very high
August Weather	24°C (76°F)	144 mm (5.7 inches)	72%	very high
September Weather	21°C (70°F)	111 mm (4.4 inches)	75%	very high
October Weather	16°C (60°F)	101 mm (4.0 inches)	81%	high
November Weather	7°C (46°F)	88 mm (3.5 inches)	85%	moderate
December Weather	4°C (39°F)	98 mm (3.9 inches)	84%	moderate