Last updated: August 21, 2025
December in Oshima, Japan brings a mild yet refreshing climate, with maximum temperatures reaching 21°C (71°F) and a comfortable average of 12°C (55°F). As the month progresses, temperatures can dip to a minimum of 5°C (41°F), making warm layers a necessity for outdoor activities. With 95 mm (3.7 in) of precipitation spread over 12 days, the island experiences a blend of crisp air and occasional rainfall, contributing to a humidity level of 78%. This enchanting month offers a unique mix of winter charm and maritime beauty, perfect for those seeking a tranquil escape.
In December, Oshima, Japan, experiences a noticeable transition as winter begins to settle in. The temperatures drop slightly, with nighttime lows around 5°C (41°F) and daytime averages reaching about 12°C (55°F). Despite these cooler conditions, the maximum temperature can still climb to a comfortable 21°C (71°F), allowing for enjoyable outdoor activities. As the year draws to a close, this month serves as a bridge between the milder autumn and the chillier depths of winter, all while maintaining a vibrant, inviting atmosphere that reflects the island's beautiful landscapes. Whether strolling leisurely through the scenery or basking in the gentle sun, December offers a delightful blend of cool air and warmth, perfect for those looking to savor the island's unique charm.
In December, Oshima, Japan experiences a moderate precipitation amount of 95 mm (3.7 in), marking a slight decrease from the previous month's 152 mm. This reduction aligns with the trend seen in late autumn, as November typically showcases higher rainfall, possibly due to shifting weather patterns. December brings 12 rainy days, indicating a consistent, yet less intense, wet period as the region transitions into winter. Overall, while December's precipitation is lower than the peak summer months, it remains significant enough to sustain the lush landscapes characteristic of Oshima, keeping its natural beauty vibrant even in the cooler season.
In Oshima, Japan, December ushers in a humidity level of 78%, marking a slight decline from the peak summer months but remaining elevated compared to the cooler seasons. This trend highlights the island's characteristic maritime climate, with humidity gradually decreasing from the summer highs of 93% in July and 90% in August. As the year progresses, the humidity shows a gentle ebb, dropping from 81% in May to December's 78%, suggesting a shift towards drier, cooler conditions. This relatively stable humidity during the winter months offers a refreshing respite while still retaining the island's signature lushness, making Oshima a unique destination year-round.
In Oshima, Japan, the December UV Index drops back to a moderate level of 4, similar to January and November, indicating a burn time of 30 minutes. This seasonal trend showcases a clear cycle in UV exposure, with the index peaking at extreme levels of 11 in May and June, before tapering off to more manageable figures as the year ends. The transition from the intense summer months highlights the changing sun angle and shorter daylight hours, making December a time to enjoy outdoor activities with minimal risk of sunburn. For residents and visitors alike, staying informed about the UV Index is essential for safe sun exposure year-round. Explore more about UV trends in the region at Oshima UV Index.
UV Risk Categories
In Oshima, Japan, December shines with 229 hours of sunlight, marking a gentle decline from the vibrant glow of August, which boasts an impressive 313 hours. This month sits comfortably within the cooler transition to winter, maintaining a steady brightness that outshines the early months of the year like January's modest 189 hours. As the year progresses, sunlight hours tend to peak in spring and summer, while fall brings a gradual tapering. Despite December’s shorter days, it provides a warm close to the year, hinting at the promise of returning light as the cycle begins anew in January. The consistent embrace of sunlight throughout the year keeps Oshima's charm alive, offering its residents and visitors alike reasons to bask in its December warmth.
Oshima, Japan, experiences a notable shift in sunny weather as the year winds down, with December boasting a 68% chance of sunshine. This marks a significant increase from the previous months, particularly in contrast to the cooler spring and summer months like May and June, where sunny days dropped to 27% and 25% respectively. As autumn progresses, the likelihood of clear skies rises, peaking in December, which provides a refreshing end to the year. This trend suggests that visitors to Oshima during December can enjoy a delightful mix of crisp air and bright sunshine, perfect for exploring this beautiful island.
In Oshima, Japan, the daylight duration exhibits a distinct seasonal rhythm that reflects the changing time of year. Beginning with 10 hours of daylight in January and February, days gradually lengthen to 11 hours in March and peak at 14 hours during the vibrant summer months of June and July. As summer fades, daylight begins its steady decline, retreating to 13 hours in August, and further to 12 hours in September. The transition into fall brings a gradual shortening of daylight, culminating in 10 hours in November. By December, Oshima experiences the shortest days of the year, with only 9 hours of daylight. This trend illustrates the rhythmic dance of light and dark, guiding the islanders through the cycles of nature.
As December sweeps in, Oshima, Japan, experiences a brisk shift in the atmosphere, marked by an average wind speed of 9.2 m/s (21 mph). The month stands out for its renewal of stronger gusts, reminiscent of the earlier winter months, January and February, which both maintain a similar average at 9.3 m/s and 9.4 m/s respectively. Following a gentle summer lull, where speeds dropped significantly to as low as 5.0 m/s (11 mph) in June and July, the wind steadily picks up again in the fall, culminating in November's peak of 7.9 m/s (18 mph). This trend reflects the island's dynamic weather patterns, where the refreshing December winds herald the upcoming chill of winter, inviting a sense of invigorating change in the serene coastal landscape.
Weather in Oshima varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Oshima, focusing on differences in temperature, rainfall, humidity, and UV levels.
In December, the weather is generally milder with average temperatures reaching up to 12°C (55°F), while January sees a slight dip with average temperatures around 10°C (50°F). December experiences more variability, with maximum temperatures peaking at 21°C (71°F), compared to January's maximum of 18°C (65°F). Precipitation is relatively similar between the two months, with December recording 95 mm (3.7 in) over 12 days, compared to January's 91 mm (3.6 in) over just 9 days. Additionally, humidity is slightly higher in December at 78%, compared to 76% in January. For more details on January's weather, you can check Oshima weather in January.
December and February exhibit relatively mild winter weather, but there are notable differences between the two months. December typically sees slightly warmer temperatures, with averages around 12°C (55°F) and maximums reaching 21°C (71°F), whereas February averages lower at 10°C (50°F) with a maximum of 19°C (66°F). Precipitation levels are also comparable, with December receiving about 95 mm (3.7 in) over approximately 12 days, while February has slightly less at 89 mm (3.5 in) across 11 days. Additionally, humidity is a bit higher in December at 78%, compared to 74% in February. For more detailed insights on February weather, you can check Oshima weather in February.
December and March exhibit distinct weather patterns. In December, temperatures range from a minimum of 5°C (41°F) to a maximum of 21°C (71°F), with an average of 12°C (55°F). The month experiences 95 mm (3.7 in) of precipitation over 12 days, combined with a relatively high humidity of 78%. In contrast, March shows a slightly warmer temperature profile, with an average of 13°C (55°F) and a maximum of 19°C (66°F), while maintaining a minimum of 5°C (42°F). However, it is also wetter, with precipitation reaching 201 mm (7.9 in) over 14 days and a lower humidity of 70%. For more specific details on weather conditions in March, you can visit Oshima weather in March.
In December, temperatures range from a minimum of 5°C (41°F) to a maximum of 21°C (71°F), with an average of 12°C (55°F). The month sees approximately 95 mm (3.7 in) of precipitation over 12 days, accompanied by a humidity level of 78%. In contrast, April experiences slightly warmer temperatures, with a minimum of 7°C (46°F) and an average of 15°C (59°F), while still peaking at 21°C (71°F). However, precipitation is higher in April, totaling 157 mm (6.2 in) over the same number of days, and humidity decreases slightly to 74%. For more details, you can visit Oshima weather in April.
In December, the weather is relatively mild, with temperatures ranging from a minimum of 5°C (41°F) to a maximum of 21°C (71°F) and an average of 12°C (55°F). The month experiences significant rainfall, totaling 95 mm (3.7 in) across 12 days, with humidity hovering around 78%. In contrast, May brings warmer conditions, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 23°C (73°F) and an average of 19°C (66°F). Rainfall increases substantially in May, reaching 198 mm (7.8 in) over 11 days, accompanied by slightly higher humidity at 81%. For a more detailed look at May's weather, you can check Oshima weather in May.
In December, the weather is characterized by milder temperatures, with a minimum of 5°C (41°F) and an average of 12°C (55°F), peaking at 21°C (71°F). The month sees moderate precipitation of 95 mm (3.7 in) over 12 days, accompanied by a humidity level of 78%. In contrast, June experiences warmer conditions, with temperatures ranging from a minimum of 17°C (63°F) to an average of 22°C (71°F), reaching a maximum of 25°C (78°F). However, June is significantly wetter, with precipitation totaling 277 mm (10.9 in) over 14 days and higher humidity at 88%. This shift from December’s cooler and drier climate to the warm, rainy summer months creates a notable contrast in the yearly weather pattern. For more insights on June weather, check out Oshima weather in June.
December and July offer contrasting weather conditions. In December, temperatures range from a minimum of 5°C (41°F) to a maximum of 21°C (71°F), with an average of 12°C (55°F). The month experiences about 95 mm (3.7 in) of precipitation over 12 days and maintains a humidity level of 78%. In sharp contrast, July sees much warmer temperatures, with a minimum of 20°C (69°F) and a maximum of 29°C (85°F), averaging around 25°C (77°F). This month is notably wetter, receiving approximately 301 mm (11.9 in) of rain over 15 days, accompanied by higher humidity at 93%. For more details on July weather, you can check Oshima weather in July.
December and August present contrasting weather patterns, showcasing the diversity of the seasons. In December, temperatures range from a minimum of 5°C (41°F) to a maximum of 21°C (71°F), with an average of 12°C (55°F). The month experiences 95 mm (3.7 in) of precipitation over about 12 days, with humidity lingering at 78%. Conversely, August boasts considerably warmer temperatures, with a minimum of 22°C (72°F) and a max of 29°C (85°F), leading to an average of 27°C (80°F). Precipitation increases to 155 mm (6.1 in) over 13 days, coupled with a higher humidity of 90%. For more detailed info about the weather in August, check out Oshima weather in August.
When comparing the weather of December and September, notable differences emerge in temperature, precipitation, and humidity patterns. December features milder temperatures, with a minimum of 5°C (41°F) and an average of 12°C (55°F), while September enjoys warmer conditions, ranging from a minimum of 19°C (67°F) to an average of 25°C (76°F). In terms of precipitation, September is significantly wetter, receiving 249 mm (9.8 in) over 19 days compared to December's 95 mm (3.7 in) on 12 days. Humidity is also higher in September at 86%, compared to December's 78%. For more detailed information, you can check Oshima weather in September.
In comparing the weather patterns of December and October, October typically offers warmer temperatures with a range from a minimum of 15°C (59°F) to a maximum of 27°C (80°F), averaging 21°C (70°F). In contrast, December experiences cooler temperatures, with a minimum of 5°C (41°F) and a maximum of 21°C (71°F), averaging around 12°C (55°F). Precipitation is notably higher in October, totaling 339 mm (13.4 in) across 18 days, compared to December's 95 mm (3.7 in) over 12 days. Additionally, October's humidity is slightly higher at 83%, compared to December's 78%. For more details on October weather specifics, you can refer to Oshima weather in October.
In comparing the weather between November and December, December experiences cooler temperatures, with a minimum of 5°C (41°F) and an average of 12°C (55°F), whereas November is slightly warmer, featuring a minimum of 8°C (47°F) and an average of 17°C (63°F). Additionally, November has higher precipitation levels at 152 mm (6.0 in) over 15 days, compared to December's 95 mm (3.7 in) across 12 days. Humidity remains relatively similar in both months, with November at 80% and December at 78%. For more detailed insights about November, you can refer to Oshima weather in November.
As December rolls in, Oshima experiences a notable shift in weather, transitioning from the milder conditions of autumn to a cooler, more humid atmosphere. With temperatures dipping to a comfortable yet brisk average of 12°C, this month brings a significant increase in precipitation, leading to wet and overcast days—often exceeding half of the month. The humidity stays elevated, making the cool air feel quite damp, a striking contrast to the drier, warmer months preceding it. This creates a unique environment that sets the stage for the winter season ahead. For a deeper dive into Oshima's climatic patterns throughout the year, visit Oshima Climate.