nomadseason

December Weather in Waterloo, United States

Last updated: June 24, 2025

In December, the average temperature in Waterloo, United States hovers around -2°C (29°F). Expect chilly days, with temperatures dipping as low as -22°C (-7°F) at their minimum, while occasionally reaching a maximum of 18°C (65°F). During this month, anticipate about 46 mm (1.8 in) of precipitation spread over 7 days, contributing to an average humidity level of 81%.

December Temperature in Waterloo

In December in Waterloo, the average temperature is -2°C (29°F). The maximum can reach 18°C (65°F), while the minimum can drop as low as -22°C (-7°F). Be prepared for a wide range of temperatures if you're planning to travel during this month.

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

The chart illustrates December temperature patterns in Waterloo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Waterloo, December typically has an average temperature of -2°C (29°F), with highs reaching up to 18°C (65°F) and lows dropping to around -22°C (-7°F).
JanFebMarAprMayJunJulAugSepOctNovDec212235465970747165513629
Data source: Temperature data for Waterloo generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Waterloo

In Waterloo in December, the precipitation amount is 46 mm (1.8 in) over the course of 7 days.

December Precipitation Trends in Waterloo

The chart displays monthly precipitation patterns in Waterloo, 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 Waterloo, December typically receives around 46 mm (1.8 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec515157101125114102961021154346
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in Waterloo

In Waterloo in December humidity is 81%. With an average temperature of -2°C (29°F), this humidity feels like an uncomfortable chill that seeps into your bones, making outdoor activities less enjoyable and requiring extra layers to stay warm while traveling.

December Average Humidity in Waterloo

This chart illustrates the average monthly humidity levels in Waterloo, 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 Waterloo is approximately 81%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%85%85%78%80%78%76%79%83%88%82%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Waterloo

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

Maximum UV Index Levels in Waterloo for December

The chart shows the monthly maximum UV Index (UVI) for Waterloo 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 Waterloo typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec34589101098532
Data source: Waterloo 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 Waterloo Compares to Other Months

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

This table compares monthly weather conditions in Waterloo, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-6°C (22°F)51 mm (2.0 inches)85%moderate
February Weather-5°C (22°F)51 mm (2.0 inches)85%moderate
March Weather2°C (36°F)57 mm (2.3 inches)85%moderate
April Weather8°C (46°F)100 mm (4.0 inches)85%very high
May Weather15°C (59°F)125 mm (4.9 inches)78%very high
June Weather21°C (70°F)114 mm (4.5 inches)80%very high
July Weather23°C (75°F)102 mm (4.0 inches)78%very high
August Weather22°C (71°F)96 mm (3.8 inches)76%very high
September Weather18°C (65°F)102 mm (4.0 inches)79%very high
October Weather11°C (51°F)115 mm (4.5 inches)83%moderate
November Weather2°C (37°F)43 mm (1.7 inches)88%moderate
December Weather-2°C (29°F)46 mm (1.8 inches)81%low

Compare Waterloo's Climate with Cities Worldwide