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December Weather in Hillsboro, United States

Last updated: June 24, 2025

In December, the average temperature in Hillsboro, United States hovers around 12°C (53°F). Expect a minimum chill of -4°C (26°F) and a maximum warmth of 30°C (86°F). With 56 mm (2.2 in) of precipitation spread over 6 days, it's wise to prepare for some rain. Additionally, the average humidity is a high 87%, contributing to the overall dampness of the air.

December Temperature in Hillsboro

Visiting Hillsboro in December offers a pleasant climate, with average temperatures around 12°C (53°F), but be prepared for fluctuations as highs can soar to 30°C (86°F) and lows can drop to -4°C (26°F).

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

The chart illustrates December temperature patterns in Hillsboro, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hillsboro, December typically has an average temperature of 12°C (53°F), with highs reaching up to 30°C (86°F) and lows dropping to around -4°C (26°F).
JanFebMarAprMayJunJulAugSepOctNovDec485061667582868680695853
Data source: Temperature data for Hillsboro 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 Hillsboro

In Hillsboro in December, the precipitation amount is 56 mm (2.2 in) spread over 6 days.

December Precipitation Trends in Hillsboro

The chart displays monthly precipitation patterns in Hillsboro, 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 Hillsboro, December typically receives around 56 mm (2.2 inches) of precipitation spread over approximately 6 days.
JanFebMarAprMayJunJulAugSepOctNovDec598685102176705591781314457
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Hillsboro

In Hillsboro in December, humidity is 87%. With an average temperature of 12°C (53°F), this humidity feels like a damp blanket enveloping you, making travel uncomfortable and stifling, as the air thickens and clings to your skin, sapping your energy as you navigate the sights.

December Average Humidity in Hillsboro

This chart illustrates the average monthly humidity levels in Hillsboro, 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 Hillsboro is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec80%80%78%79%81%77%71%67%69%73%82%87%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Hillsboro

In Hillsboro 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 Hillsboro for better planning.

Maximum UV Index Levels in Hillsboro for December

The chart shows the monthly maximum UV Index (UVI) for Hillsboro 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 Hillsboro typically reaches 4, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec478101111111110864
Data source: Hillsboro 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 Hillsboro Compares to Other Months

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

This table compares monthly weather conditions in Hillsboro, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather9°C (49°F)59 mm (2.3 inches)79%moderate
February Weather10°C (51°F)86 mm (3.4 inches)80%high
March Weather16°C (62°F)85 mm (3.3 inches)78%very high
April Weather19°C (67°F)102 mm (4.0 inches)79%very high
May Weather24°C (75°F)176 mm (6.9 inches)81%extreme
June Weather28°C (82°F)70 mm (2.8 inches)77%extreme
July Weather30°C (86°F)55 mm (2.2 inches)71%extreme
August Weather30°C (86°F)91 mm (3.6 inches)67%extreme
September Weather27°C (80°F)77 mm (3.1 inches)69%very high
October Weather21°C (69°F)131 mm (5.2 inches)73%very high
November Weather14°C (58°F)44 mm (1.7 inches)82%high
December Weather12°C (53°F)56 mm (2.2 inches)87%moderate

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