nomadseason

December Weather in Waterloo, United States

Last updated: June 24, 2025

In December, the average temperature in Waterloo, United States hovers around 0°C (32°F). While you may experience minimums as low as -25°C (-13°F), the highs can reach an inviting 21°C (70°F). Expect about 40 mm (1.6 in) of precipitation over 4 days, contributing to an average humidity of 83%. Prepare accordingly for a chilly yet dynamic month!

December Temperature in Waterloo

In December in Waterloo, the average temperature is 0°C (32°F). Maximums can reach 21°C (70°F) and minimums can be as low as -25°C (-13°F). Be prepared for a wide range of temperatures if you're planning to travel there during this time.

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 0°C (32°F), with highs reaching up to 21°C (70°F) and lows dropping to around -25°C (-13°F).
JanFebMarAprMayJunJulAugSepOctNovDec252541506376787570534031
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 40 mm (1.6 in) spread over a duration of 4 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 40 mm (1.6 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec3330975414612674101831153140
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 83%. With an average temperature of 0°C (32°F), this humidity feels like traveling through a thick mist, making every step heavy and the cold pierce even deeper, causing you to constantly seek shelter or warm beverages to counteract the damp chill.

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 83%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%80%73%75%78%82%83%81%75%75%82%83%
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.
JanFebMarAprMayJunJulAugSepOctNovDec356810101098642
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-4°C (25°F)32 mm (1.3 inches)76%moderate
February Weather-4°C (26°F)30 mm (1.2 inches)80%moderate
March Weather5°C (41°F)97 mm (3.8 inches)73%high
April Weather10°C (51°F)54 mm (2.1 inches)74%very high
May Weather17°C (63°F)146 mm (5.8 inches)78%very high
June Weather24°C (76°F)126 mm (5.0 inches)82%very high
July Weather26°C (78°F)74 mm (2.9 inches)83%very high
August Weather24°C (75°F)100 mm (4.0 inches)80%very high
September Weather21°C (70°F)83 mm (3.3 inches)75%very high
October Weather11°C (53°F)115 mm (4.5 inches)75%high
November Weather5°C (40°F)31 mm (1.2 inches)82%moderate
December Weather0°C (32°F)40 mm (1.6 inches)83%low

Compare Waterloo's Climate with Cities Worldwide