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December Weather in Hartley, United States

Last updated: June 24, 2025

In December, the average temperature in Hartley, United States hovers around 4°C (40°F), with a range that can dip as low as -13°C (10°F) and reach as high as 23°C (74°F). Expect a bit of moisture, with an average precipitation amount of 14 mm (0.6 in) over 2 days, coupled with a notable average humidity of 77%. Stay prepared for a mix of chilly and mild weather!

December Temperature in Hartley

In December in Hartley, the average temperature is 4°C (40°F). Maximums can reach 23°C (74°F), while minimums can drop as low as -13°C (10°F). Be prepared for a wide range of temperatures when traveling during this time.

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

The chart illustrates December temperature patterns in Hartley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hartley, December typically has an average temperature of 4°C (40°F), with highs reaching up to 23°C (74°F) and lows dropping to around -13°C (10°F).
JanFebMarAprMayJunJulAugSepOctNovDec373849556676797771574739
Data source: Temperature data for Hartley 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 Hartley

In Hartley in December, the precipitation amount is 14 mm (0.6 in) over a period of 2 days.

December Precipitation Trends in Hartley

The chart displays monthly precipitation patterns in Hartley, 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 Hartley, December typically receives around 14 mm (0.6 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec151039375943295431501214
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Hartley

In Hartley in December humidity is 77%. With an average temperature of 4°C (40°F), this humidity feels like a damp chill that penetrates your clothing, making outdoor exploration less enjoyable and prompting travelers to seek shelter or warm indoor activities instead.

December Average Humidity in Hartley

This chart illustrates the average monthly humidity levels in Hartley, 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 Hartley is approximately 77%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec74%75%61%62%69%74%75%78%76%76%80%77%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Hartley

In Hartley 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 Hartley for better planning.

Maximum UV Index Levels in Hartley for December

The chart shows the monthly maximum UV Index (UVI) for Hartley 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 Hartley typically reaches 4, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468111112121110754
Data source: Hartley 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 Hartley Compares to Other Months

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

This table compares monthly weather conditions in Hartley, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather3°C (37°F)15 mm (0.6 inches)74%moderate
February Weather3°C (39°F)10 mm (0.4 inches)75%high
March Weather10°C (50°F)39 mm (1.5 inches)61%very high
April Weather13°C (56°F)37 mm (1.5 inches)61%extreme
May Weather19°C (66°F)58 mm (2.3 inches)69%extreme
June Weather24°C (76°F)43 mm (1.7 inches)74%extreme
July Weather26°C (79°F)29 mm (1.1 inches)75%extreme
August Weather25°C (77°F)54 mm (2.1 inches)78%extreme
September Weather22°C (71°F)31 mm (1.2 inches)76%very high
October Weather14°C (57°F)50 mm (2.0 inches)76%high
November Weather8°C (47°F)11 mm (0.5 inches)80%moderate
December Weather4°C (40°F)14 mm (0.6 inches)77%moderate

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