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December Weather in Saint Johns, United States

Last updated: June 24, 2025

In December, the average temperature in Saint Johns, United States hovers around 3°C (37°F). However, temperatures can vary significantly, with a minimum of -21°C (-6°F) and a maximum of 19°C (66°F). During this month, expect 19 mm (0.8 in) of precipitation spread over 4 days, contributing to an average humidity of 82%. Stay prepared for a mix of chilly mornings and the occasional mild afternoon!

December Temperature in Saint Johns

In December in Saint Johns, the average temperature is 3°C (37°F). Maximums can reach 19°C (66°F), while minimums can drop as low as -21°C (-6°F). Be prepared for a wide temperature range during your travels, with the possibility of both chilly and mild weather.

December Weather in Saint Johns: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Saint Johns, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Johns, December typically has an average temperature of 3°C (37°F), with highs reaching up to 19°C (66°F) and lows dropping to around -21°C (-6°F).
JanFebMarAprMayJunJulAugSepOctNovDec364048566476777569574637
Data source: Temperature data for Saint Johns 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 Saint Johns

In Saint Johns in December, the precipitation amount is 19 mm (0.8 in) over a span of 4 days.

December Precipitation Trends in Saint Johns

The chart displays monthly precipitation patterns in Saint Johns, 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 Saint Johns, December typically receives around 19 mm (0.8 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec2529211396331919171220
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Saint Johns

In Saint Johns in December, humidity is 82%. With an average temperature of 3°C (37°F), this humidity feels like an uncomfortable chill that wraps around you, making outdoor activities less enjoyable and prompting a constant search for warmth.

December Average Humidity in Saint Johns

This chart illustrates the average monthly humidity levels in Saint Johns, 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 Saint Johns is approximately 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec81%83%71%61%48%36%37%46%62%74%82%82%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Saint Johns

In Saint Johns in December, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Saint Johns.

Maximum UV Index Levels in Saint Johns for December

The chart shows the monthly maximum UV Index (UVI) for Saint Johns 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 Saint Johns typically reaches 5, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec5710121213131211865
Data source: Saint Johns 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 Saint Johns Compares to Other Months

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

This table compares monthly weather conditions in Saint Johns, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather2°C (36°F)25 mm (1.0 inches)81%moderate
February Weather4°C (40°F)29 mm (1.1 inches)83%high
March Weather9°C (48°F)21 mm (0.8 inches)71%very high
April Weather14°C (57°F)13 mm (0.5 inches)61%extreme
May Weather18°C (64°F)9 mm (0.4 inches)48%extreme
June Weather24°C (76°F)6 mm (0.3 inches)36%extreme
July Weather25°C (77°F)32 mm (1.3 inches)37%extreme
August Weather24°C (76°F)19 mm (0.8 inches)46%extreme
September Weather21°C (69°F)19 mm (0.8 inches)62%extreme
October Weather14°C (57°F)17 mm (0.7 inches)74%very high
November Weather8°C (47°F)12 mm (0.5 inches)82%high
December Weather3°C (37°F)19 mm (0.8 inches)82%moderate

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