December Weather in St. Marys

Last updated: March 2, 2024

The weather in St. Marys, United States, during December is characterized by an average temperature of 15°C (59°F). Highs can soar to 25°C (77°F), while lows may dip to 3°C (38°F). Typically, the humidity level in St. Marys throughout December hovers around 85%.

3°C (38°F)

Minimum temperature

15°C (59°F)

Average temperature

25°C (77°F)

Maximum temperature

85%

Humidity

Precipitation and Sunshine hours

In December, St. Marys averages 86 mm (3.4 inches) of rainfall, typically over the course of 7 rainy days. The month enjoys an average of 10 hours 10 minutes of daylight, with the sun shining for approximately 7 hours 13 minutes each day. Additionally, there is a 45% probability of sunny days during this period.

86 mm (3.4 inches)

Precipitation

7 rainy days

Rainy days

7 hours 13 minutes

Sunshine hours

45%

Chance of sun

UV Index

In December, the UV Index in St. Marys reaches a maximum of 4, indicating a level of Moderate exposure. The most intense UV radiation typically occurs between 11:00 and 13:00, during which unprotected skin may burn in as little as 30 minutes.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
  07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00
UVI 0 1 2 3 4 4 4 3 2 1 1 0 0
Exposure Low Moderate Low
Time to burn 45 min 30 min 45 min

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