December weather forecast
Nagasaki, Japan

Finally, the year in Nagasaki comes full circle with December introducing the winter environment, dipping the average high and low temperatures to 13.1°C (55.6°F) and 5.9°C (42.6°F) respectively. After a long period of no snowfall from April to November, snow again becomes a possibility in December with an average of 10mm (0.39"). The city echoes with a festive spirit under the winter sky, which sparkles with holiday lights. Despite the onset of cooler days and chillier nights, the city’s vibrant cultural scene continues unabashed. As December dramatically concludes the year, expect January to roll in with a colder atmosphere and a fresh start for Nagasaki's weather cycle.

Temperature

December ushers in a slight temperature change in Nagasaki, with average high-temperatures reducing from November's refreshing 18.3°C (64.9°F) to a moderate 13.1°C (55.6°F). During the nights in December, an average low-temperature of 5.9°C (42.6°F) is observed in Nagasaki, Japan.

Humidity

The average relative humidity in December is 66%.

Rainfall

December is the month with the least rainfall in Nagasaki, Japan. Rain falls for 10 days and accumulates 61mm (2.4") of precipitation.

Snowfall

January, February and December are months with snowfall. December is the first month it typically snows in Nagasaki. Throughout December, in the average 0.2 snowfall days, it receives 10mm (0.39") of snow. In Nagasaki, during the entire year, snow falls for 2.5 days and aggregates up to 40mm (1.57") of snow.

Sea temperature

In December, the average sea temperature in Nagasaki, Japan, is 18.4°C (65.1°F).
Note: Most people do not take pleasure in swimming in water at 18.4°C (65.1°F). The difficulty of managing breathing increases as the water temperature dips from 21°C (69.8°F) to 15°C (59°F).

Daylight

The month with the shortest days is December, with an average of 10h and 0min of daylight.
On the first day of the month, sunrise is at 07:04 and sunset at 17:14. On the last day of December, sunrise is at 07:22 and sunset at 17:24 JST.

Sunshine

The average sunshine in December in Nagasaki is 3.8h.

UV index

The months with the lowest UV index are January and December, with an average maximum UV index of 3. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: In December, an average UV index of 3 transforms into the following instructions:
Act with care - Obligation to protect against skin and eye damage is highlighted. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.