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December Weather in Cortland, United States

Last updated: June 24, 2025

In December, the average temperature in Cortland, United States hovers around -1°C (30°F). Temperatures can drop as low as -19°C (-3°F), while reaching a maximum of 16°C (62°F). Expect 102 mm (4.0 in) of precipitation spread over 16 days, accompanied by a high average humidity of 86%.

December Temperature in Cortland

In December in Cortland, the average temperature is -1°C (30°F). The maximum can reach 16°C (62°F) and the minimum can be as low as -19°C (-3°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

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

The chart illustrates December temperature patterns in Cortland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Cortland, December typically has an average temperature of -1°C (30°F), with highs reaching up to 16°C (62°F) and lows dropping to around -19°C (-3°F).
JanFebMarAprMayJunJulAugSepOctNovDec242733455766716962523730
Data source: Temperature data for Cortland 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 Cortland

In Cortland in December, the precipitation amount is 102 mm (4.0 in) spread over 16 days.

December Precipitation Trends in Cortland

The chart displays monthly precipitation patterns in Cortland, 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 Cortland, December typically receives around 102 mm (4.0 inches) of precipitation spread over approximately 16 days.
JanFebMarAprMayJunJulAugSepOctNovDec89969112413710516311699155102103
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Cortland

In Cortland in December, humidity is 86%. With an average temperature of -1°C (30°F), this humidity feels like a heavy blanket wrapping around you, making traveling feel much colder and more uncomfortable than the temperature suggests.

December Average Humidity in Cortland

This chart illustrates the average monthly humidity levels in Cortland, 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 Cortland is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%90%87%88%82%79%78%76%78%84%89%86%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Cortland

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

Maximum UV Index Levels in Cortland for December

The chart shows the monthly maximum UV Index (UVI) for Cortland 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 Cortland typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec346810101098642
Data source: Cortland 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 Cortland Compares to Other Months

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

This table compares monthly weather conditions in Cortland, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (25°F)88 mm (3.5 inches)90%moderate
February Weather-3°C (27°F)96 mm (3.8 inches)90%moderate
March Weather1°C (34°F)91 mm (3.6 inches)87%high
April Weather7°C (45°F)124 mm (4.9 inches)88%very high
May Weather14°C (57°F)137 mm (5.4 inches)82%very high
June Weather19°C (66°F)105 mm (4.1 inches)79%very high
July Weather21°C (71°F)163 mm (6.4 inches)78%very high
August Weather20°C (69°F)116 mm (4.6 inches)76%very high
September Weather17°C (62°F)99 mm (3.9 inches)78%very high
October Weather11°C (52°F)155 mm (6.1 inches)84%high
November Weather3°C (37°F)102 mm (4.0 inches)89%moderate
December Weather-1°C (30°F)102 mm (4.0 inches)86%low

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