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December Weather in Petersburg, United States

Last updated: June 24, 2025

In December, the average temperature in Petersburg, United States hovers around 4°C (40°F). While temperatures can dip as low as -16°C (3°F), they can also reach a pleasant 21°C (71°F). Be prepared for 104 mm (4.1 in) of precipitation spread over 10 days, contributing to a high average humidity of 87%. Ideal for cozy indoor activities or enjoying the refreshing atmosphere!

December Temperature in Petersburg

In December in Petersburg, the average temperature is 4°C (40°F), with maximums reaching up to 21°C (71°F) and minimums dropping as low as -16°C (3°F). Travelers should be prepared for a wide range of temperatures and pack accordingly for both warm and cold conditions.

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

The chart illustrates December temperature patterns in Petersburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Petersburg, December typically has an average temperature of 4°C (40°F), with highs reaching up to 21°C (71°F) and lows dropping to around -16°C (3°F).
JanFebMarAprMayJunJulAugSepOctNovDec343847566876797772614540
Data source: Temperature data for Petersburg 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 Petersburg

In Petersburg in December, the precipitation amount is 104 mm (4.1 in) over a period of 10 days.

December Precipitation Trends in Petersburg

The chart displays monthly precipitation patterns in Petersburg, 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 Petersburg, December typically receives around 104 mm (4.1 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec9111714712413712577897710598104
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Petersburg

In Petersburg in December humidity is 87%. With an average temperature of 4°C (40°F), this humidity feels like an uncomfortable chill that seeps into your bones, making it essential to dress warmly and prepare for damp conditions, which can dampen your spirits while traveling.

December Average Humidity in Petersburg

This chart illustrates the average monthly humidity levels in Petersburg, 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 Petersburg is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%85%86%84%79%82%79%70%69%76%88%87%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Petersburg

In Petersburg 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 Petersburg, you can check the information here.

Maximum UV Index Levels in Petersburg for December

The chart shows the monthly maximum UV Index (UVI) for Petersburg 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 Petersburg typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3571010111099643
Data source: Petersburg 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 Petersburg Compares to Other Months

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

This table compares monthly weather conditions in Petersburg, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)91 mm (3.6 inches)87%moderate
February Weather3°C (38°F)117 mm (4.6 inches)85%moderate
March Weather8°C (48°F)147 mm (5.8 inches)86%high
April Weather13°C (56°F)124 mm (4.9 inches)84%very high
May Weather20°C (68°F)137 mm (5.4 inches)79%very high
June Weather25°C (76°F)125 mm (4.9 inches)82%extreme
July Weather26°C (80°F)77 mm (3.0 inches)79%very high
August Weather25°C (77°F)89 mm (3.5 inches)70%very high
September Weather22°C (73°F)77 mm (3.0 inches)69%very high
October Weather16°C (61°F)105 mm (4.1 inches)76%high
November Weather7°C (45°F)98 mm (3.8 inches)88%moderate
December Weather4°C (40°F)104 mm (4.1 inches)87%moderate

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