Last updated: August 21, 2025
September in Oshima, Japan is characterized by warm temperatures and high humidity levels, creating a tropical ambiance. Daily maximums reach up to 29°C (84°F), while the average temperature hovers around 25°C (76°F). Nights are cooler with a minimum of 19°C (67°F). This month sees considerable rainfall, accumulating to 249 mm (9.8 in) over 19 days, making it one of the wetter periods of the year. The atmosphere, laden with moisture at 86% humidity, contributes to the lush landscapes, setting a serene backdrop for visitors and locals alike.
In September, Oshima, Japan, transitions into a pleasantly warm early autumn, with temperatures ranging from a mild 19°C (67°F) at night to a comfortable 29°C (84°F) during the day. This month averages 25°C (76°F), showcasing a slight dip from the sweltering summer months, yet still retaining a pleasant warmth for outdoor activities. As the island welcomes cooler breezes and the vibrant hues of fall, September stands out as a perfect time to explore Oshima’s natural beauty, making it an ideal destination for travelers seeking a respite from the heat without the chill of winter.
In September, Oshima, Japan experiences a significant uptick in rainfall, with precipitation reaching 249 mm (9.8 in) over the course of 19 days. This marks a noticeable transition from the relatively drier summer months, as August had seen just 155 mm (6.1 in) of rain spread across 13 days. The increase in precipitation is part of a broader trend leading into autumn, as October further intensifies with 339 mm (13.4 in) expected on 18 days. This September surge not only reflects the shifting seasons but also contributes to the overall lushness of the island's landscapes, setting a picturesque scene as nature prepares for the impending cooler months.
As summer transitions into autumn, September in Oshima, Japan, exhibits a notable humidity level of 86%—a slight decrease from the peak of 93% in July. Throughout the summer months, humidity remains high, with both July and August consistently hovering in the 90s, creating a muggy and tropical atmosphere. However, September’s drop signifies a gentle shift towards more temperate conditions as the island prepares for autumn. This elevated, yet less oppressive humidity compared to the summer months helps foster a lush landscape while hinting at the cooler, more comfortable temperatures that October will bring, where humidity settles at 83%. Overall, the trend showcases a gradual decline in humidity as the year progresses, reflecting the dynamic climatic changes in Oshima.
As summer transitions into fall, September in Oshima, Japan, sees a slight dip in the UV Index, settling at 10, which falls into the very high exposure category. This is a decrease from the peak of extreme levels recorded in the preceding months of June, July, and August. With a burn time of just 15 minutes, it's crucial for sun-seekers to remain vigilant about sun protection, as UV radiation remains significant. This trend of higher UV levels during the summer months, tapering off in the early autumn, underscores the importance of adapting sun safety practices throughout the year. For more detailed insights on UV exposure throughout the year, visit Oshima UV Index.
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September in Oshima, Japan, offers a delightful blend of summer's warmth and autumn's embrace, with 254 hours of sunshine lighting up the month. This provides a gentle transition from the sun-soaked days of August, which boasts the highest sunshine total at 313 hours, to the cooler, cloudier days ahead in October, which sees a drop to 216 hours. The data reveals a consistent upward trend in sunlight from January through August, peaking before a gradual descent as the season shifts. As September approaches, the sunshine remains abundant, allowing locals and visitors alike to enjoy the lingering summer vibes while bidding farewell to the longer days. This balance of light creates an inviting atmosphere, perfect for exploring the natural beauty of Oshima before the autumn chill sets in.
In Oshima, Japan, the likelihood of sunny weather experiences a shift as summer transitions to autumn. September boasts a 31% chance of sun, reflecting a dip from the sunnier summer months. This trend follows the peak sunshine rates of the earlier months, with January achieving 54% and February soaring to 63%. As the year progresses, the likelihood of sunshine generally fluctuates, with notable increases in the colder months, notably reaching 68% in December. Overall, September serves as a reminder of the changing seasons, where the warmth of summer gives way to the richer hues of fall, while the promise of sunshine dwindles leading into the months ahead.
As September unfolds in Oshima, Japan, the island experiences a gradual transition in daylight duration, with the sun gracing the skies for approximately 12 hours each day. This marks a gentle decline from the peak summer months of 14 hours in June and July, reflecting the natural shift towards autumn. Much like the vibrant foliage that begins to emerge, daylight in September is still generous, yet it subtly hints at the shorter days to come. Following this month, October offers just 11 hours of sunlight, reinforcing the trend of diminishing daylight as the year progresses. The rhythm of the seasons is beautifully encapsulated in this gradual waning of daylight, inviting residents and visitors alike to savor the last lingering moments of summer sun.
As summer transitions to autumn in Oshima, Japan, September brings a noticeable uptick in average wind speed, reaching 7.4 m/s (17 mph). This gentle breeze signifies a shift from the calmer summer months, with July and August recording lower speeds of 5.0 m/s (11 mph) and 6.8 m/s (15 mph), respectively. The winds begin to gather strength as fall approaches, paving the way for the brisker conditions of October and November, where speeds rise again to 7.1 m/s (16 mph) and 7.9 m/s (18 mph). Overall, the data showcases a trend of increasing windiness as the year progresses, heralding the cooler and more dynamic months ahead.
Weather in Oshima varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Oshima, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present distinctly contrasting weather patterns. In September, temperatures are considerably higher, with averages around 25°C (76°F) and daily highs reaching up to 29°C (84°F), while January experiences much cooler temperatures, averaging just 10°C (50°F) and peaking at 18°C (65°F). Precipitation is significantly greater in September, totaling 249 mm (9.8 in) over 19 days, compared to January's 91 mm (3.6 in) over just 9 days. Additionally, September's humidity level is relatively high at 86%, while January's humidity is more moderate at 76%. For more detailed insights into January weather, you can check Oshima weather in January.
September and February present contrasting weather experiences. In September, temperatures range from a comfortable minimum of 19°C (67°F) to a warm maximum of 29°C (84°F), with an average of 25°C (76°F). This month also sees substantial rainfall, totaling 249 mm (9.8 in) over 19 days, contributing to a high humidity level of 86%. In stark contrast, February brings much cooler temperatures, with a minimum of 4°C (39°F) and a maximum of 19°C (66°F), averaging only 10°C (50°F). Precipitation drops significantly to 89 mm (3.5 in) across 11 days, and humidity decreases to 74%. For a deeper look at February conditions, visit Oshima weather in February.
In September, the weather is notably warmer, with average temperatures ranging from a minimum of 19°C (67°F) to a maximum of 29°C (84°F), while March experiences much cooler conditions, with highs only reaching 19°C (66°F) and lows dipping to 5°C (42°F). September also sees significantly higher humidity at 86% and more precipitation, with 249 mm (9.8 in) over 19 days, compared to March's 201 mm (7.9 in) over just 14 days and a lower humidity of 70%. This stark contrast makes September feel much more tropical, whereas March carries the crispiness of early spring. For more details on March weather out there, check Oshima weather in March.
In September, the weather is notably warmer with an average temperature of 25°C (76°F) and highs reaching up to 29°C (84°F), while April presents a cooler climate, averaging only 15°C (59°F) with maximum temperatures of 21°C (71°F). September experiences higher humidity at 86% compared to April's 74%, contributing to a more muggy feel during the former month. Additionally, September sees more precipitation, with 249 mm (9.8 in) over 19 days, compared to April's 157 mm (6.2 in) over just 12 days. For more details on April weather, you can check Oshima weather in April.
September and May showcase distinct weather patterns. September typically experiences warmer temperatures, with a minimum of 19°C (67°F) and an average high of 29°C (84°F), while May is cooler, ranging from a minimum of 13°C (56°F) to a maximum of 23°C (73°F). In terms of precipitation, September is wetter, receiving 249 mm (9.8 in) over 19 days compared to May's 198 mm (7.8 in) over just 11 days. Additionally, the humidity in September is higher at 86%, compared to May's 81%. For a more detailed look, check out Oshima weather in May.
In comparing the weather between September and June, we can observe several notable differences. September tends to be warmer overall, with average temperatures reaching 25°C (76°F) and maxima of 29°C (84°F), compared to June's average of 22°C (71°F) and maximum of 25°C (78°F). However, September experiences more rain, with 249 mm (9.8 in) of precipitation over 19 days, while June sees slightly higher rainfall at 277 mm (10.9 in) but over fewer days—just 14. Additionally, humidity levels are quite similar, with September at 86% and June at 88%. For more details on the weather in June, you can check Oshima weather in June.
In comparing the weather between September and July, both months display similar average temperatures, hovering around 25°C (77°F), with July slightly warmer at a minimum of 20°C (69°F), while September starts a bit cooler at 19°C (67°F). Both months reach a maximum of 29°C (84°F), highlighting a consistent peak temperature. However, July experiences more significant rainfall, with total precipitation at 301 mm (11.9 in) over 15 days, compared to September's 249 mm (9.8 in) over 19 days. Additionally, July has a higher humidity level at 93%, versus September's 86%, making July feel more muggy and tropical. For a detailed look at July's weather trends, you can check out Oshima weather in July.
In comparing the weather of September and August, September tends to be slightly cooler with a minimum temperature of 19°C (67°F) compared to August's minimum of 22°C (72°F). The average temperature in September is also lower at 25°C (76°F), whereas August enjoys a warmer average of 27°C (80°F). Both months share a maximum temperature of 29°C (84°F in September and 85°F in August). Precipitation in September is significantly higher, with 249 mm (9.8 in) falling over 19 days, compared to August's 155 mm (6.1 in) over just 13 days. Humidity levels are comparable, with September at 86% and August at 90%. For more detailed information about August weather, you can visit Oshima weather in August.
In comparing the weather between September and October, we see a noticeable shift in temperature and precipitation patterns. September tends to be warmer, with average temperatures ranging from a minimum of 19°C (67°F) to a maximum of 29°C (84°F), while October’s temperatures drop slightly, with a range of 15°C (59°F) to 27°C (80°F). Despite the cooler temperatures in October, it experiences a higher total rainfall of 339 mm (13.4 in), compared to September's 249 mm (9.8 in). Additionally, September has a slightly higher humidity level at 86%, while October's humidity is recorded at 83%. For more detailed information, you can check Oshima weather in October.
September and November present quite different weather experiences. In September, temperatures are significantly warmer, ranging from a minimum of 19°C (67°F) to a maximum of 29°C (84°F), with an average of 25°C (76°F). This month is also characterized by high humidity at 86% and considerable rainfall, totaling 249 mm (9.8 in) over 19 days. In contrast, November sees cooler temperatures, with lows dropping to 8°C (47°F) and highs reaching 23°C (73°F), averaging 17°C (63°F). The precipitation decreases to 152 mm (6.0 in) over 15 days, and humidity drops to 80%, making November feel crisper and drier. For more specific details about weather conditions in November, you can refer to Oshima weather in November.
In September, the weather is significantly warmer and more humid, with average temperatures around 25°C (76°F) and humidity levels soaring to 86%. This month experiences substantial rainfall, averaging 249 mm (9.8 in) over 19 days, making it a rather wet period. In contrast, December brings a much cooler climate, with average temperatures dropping to 12°C (55°F) and a maximum of just 21°C (71°F). The precipitation also dramatically decreases to 95 mm (3.7 in) over only 12 days, and humidity levels are more moderate at 78%. For more detailed insights into December's weather specifics, visit Oshima weather in December.
As summer transitions to fall, September in Oshima presents a unique blend of warmth and moisture. With temperatures that still hover around pleasant levels, the month invites outdoor exploration despite being characterized by frequent rains and high humidity. Unlike the drier months of July and August, September sees significant precipitation, which contributes to the lush landscapes that define this time of year. The island's vibrant natural beauty is complemented by the cooling breezes, making it a distinctive month to experience Oshima's climate. For a detailed overview of what to expect, visit Oshima Climate.