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December Weather in Grafton, United States

Last updated: June 24, 2025

In December, the average temperature in Grafton, United States hovers around 3°C (38°F), with a dramatic range that sees lows of -17°C (1°F) and highs of 21°C (70°F). Expect about 51 mm (2.0 in) of precipitation spread over 7 days, contributing to a notably high average humidity of 86%.

December Temperature in Grafton

In December in Grafton, the average temperature is 3°C (38°F), with maximums reaching 21°C (70°F) and minimums dropping as low as -17°C (1°F). This range makes Grafton an intriguing destination for travelers seeking both chilly and mild conditions in December.

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

The chart illustrates December temperature patterns in Grafton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grafton, December typically has an average temperature of 3°C (38°F), with highs reaching up to 21°C (70°F) and lows dropping to around -17°C (1°F).
JanFebMarAprMayJunJulAugSepOctNovDec313446546776797672584438
Data source: Temperature data for Grafton 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 Grafton

In Grafton in December, the precipitation amount is 51 mm (2.0 in) over a period of 7 days.

December Precipitation Trends in Grafton

The chart displays monthly precipitation patterns in Grafton, 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 Grafton, December typically receives around 51 mm (2.0 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec70771311191479394123661006651
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Grafton

In Grafton in December humidity is 86%. With an average temperature of 3°C (38°F), this humidity feels like a damp chill that seeps through your layers, making traveling uncomfortable as breath clouds visibly in the crisp air.

December Average Humidity in Grafton

This chart illustrates the average monthly humidity levels in Grafton, 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 Grafton is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Grafton

In Grafton 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 Grafton, you can check the information here.

Maximum UV Index Levels in Grafton for December

The chart shows the monthly maximum UV Index (UVI) for Grafton 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 Grafton typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910111199643
Data source: Grafton 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 Grafton Compares to Other Months

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

This table compares monthly weather conditions in Grafton, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)70 mm (2.8 inches)82%moderate
February Weather1°C (34°F)77 mm (3.0 inches)80%moderate
March Weather8°C (46°F)131 mm (5.1 inches)80%high
April Weather12°C (55°F)119 mm (4.7 inches)80%very high
May Weather19°C (67°F)147 mm (5.8 inches)82%very high
June Weather25°C (76°F)93 mm (3.6 inches)83%extreme
July Weather26°C (79°F)94 mm (3.7 inches)81%extreme
August Weather24°C (76°F)123 mm (4.9 inches)80%very high
September Weather22°C (72°F)66 mm (2.6 inches)76%very high
October Weather15°C (59°F)100 mm (3.9 inches)76%high
November Weather6°C (44°F)66 mm (2.6 inches)85%moderate
December Weather3°C (38°F)51 mm (2.0 inches)86%moderate

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