December weather forecast
Okayama, Japan

December brings in the cold wave in Okayama, seeing temperatures drop further to 11.6°C (52.9°F) from the preceding month. A sharp decrease in rainfall to 31mm (1.22") signals the onset of the city's winter season. The second shortest daylight hours of the year means more time to enjoy the illuminations of holiday lights against the nighttime sky. Despite the increasing cold, the city does not lose any of its vibrancy with bustling holiday festivities. As the year comes to a close, Okayama provides enchanting winter scenery, setting the stage for the arrival of a new year with renewed hopes.

Temperature

The onset of December introduces a moderate change in Okayama's weather, with average high-temperatures falling from November's comfortable 16.8°C (62.2°F) to a cool 11.6°C (52.9°F). During the month of December, the nighttime temperature in Okayama falls to an average of 3.3°C (37.9°F).

Humidity

In Okayama, the average relative humidity in December is 67%.

Rainfall

December is the month with the least rainfall in Okayama. Rain falls for 15 days and accumulates 31mm (1.22") of precipitation.

Snowfall

April through December are months without snowfall.

Sea temperature

In Okayama, in December, the average water temperature is 17.1°C (62.8°F).
Note: Swimming is not a pleasant activity for most when the water temperature is 17.1°C (62.8°F). As the water temperature drops from 21°C (69.8°F) to 15°C (59°F), breathing becomes more difficult to control.

Daylight

With an average of 9h and 54min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 06:53 and sunset at 16:53. On the last day of December, in Okayama, sunrise is at 07:11 and sunset at 17:03 JST.

Sunshine

In Okayama, the average sunshine in December is 5.1h.

UV index

With an average maximum UV index of 2, December is the month with the lowest UV index in Okayama. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, a daily UV index of 2 turns into the following recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Around midday, solar radiation is most harmful; hence, exposure should be limited. Stay sun-safe with clothing that is both closely woven and worn loosely.