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December Weather in Sewickley, United States

Last updated: June 24, 2025

In December, the average temperature in Sewickley, United States hovers around 2°C (36°F). Expect temperatures to dip as low as -16°C (4°F) and peak at a comfortable 18°C (64°F). Be prepared for some rainfall, with an average precipitation of 99 mm (3.9 in) spread over 11 days. Additionally, the air can feel quite moist, with an average humidity level of 86%.

December Temperature in Sewickley

In December in Sewickley, the average temperature is 2°C (36°F). Maximum temperatures can reach 18°C (64°F), while minimums can drop as low as -16°C (4°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

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

The chart illustrates December temperature patterns in Sewickley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sewickley, December typically has an average temperature of 2°C (36°F), with highs reaching up to 18°C (64°F) and lows dropping to around -16°C (4°F).
JanFebMarAprMayJunJulAugSepOctNovDec313541516270757368574236
Data source: Temperature data for Sewickley 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 Sewickley

In Sewickley, in December, the precipitation amount is 99 mm (3.9 in) over the course of 11 days.

December Precipitation Trends in Sewickley

The chart displays monthly precipitation patterns in Sewickley, 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 Sewickley, December typically receives around 99 mm (3.9 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec92118104130136137137821221249299
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Sewickley

In Sewickley in December, humidity is 86%. With an average temperature of 2°C (36°F), this humidity feels like a biting chill that clings to your skin, making outdoor exploration uncomfortable and dampening any enthusiasm for travel.

December Average Humidity in Sewickley

This chart illustrates the average monthly humidity levels in Sewickley, 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 Sewickley is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec89%88%87%87%81%83%82%76%77%82%89%86%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Sewickley

In Sewickley 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 Sewickley, you can visit Hourly UV Index in Sewickley.

Maximum UV Index Levels in Sewickley for December

The chart shows the monthly maximum UV Index (UVI) for Sewickley 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 Sewickley typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
Data source: Sewickley 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 Sewickley Compares to Other Months

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

This table compares monthly weather conditions in Sewickley, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (31°F)92 mm (3.6 inches)88%moderate
February Weather1°C (35°F)118 mm (4.6 inches)88%moderate
March Weather5°C (42°F)104 mm (4.1 inches)87%high
April Weather11°C (52°F)130 mm (5.1 inches)87%very high
May Weather17°C (63°F)136 mm (5.4 inches)81%very high
June Weather21°C (70°F)137 mm (5.4 inches)83%very high
July Weather24°C (75°F)137 mm (5.4 inches)82%very high
August Weather23°C (73°F)82 mm (3.2 inches)76%very high
September Weather20°C (68°F)122 mm (4.8 inches)77%very high
October Weather14°C (57°F)123 mm (4.9 inches)82%high
November Weather6°C (42°F)92 mm (3.6 inches)89%moderate
December Weather2°C (36°F)99 mm (3.9 inches)86%low

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