Last updated: August 21, 2025
In September, Nagasaki experiences a warm climate characterized by an average temperature of 25°C (77°F), with daily highs reaching up to 32°C (90°F) and nighttime lows around 19°C (66°F). This month is marked by notable humidity levels at 84%, contributing to a sultry atmosphere. Rainfall is significant, with precipitation totaling 225 mm (8.9 in) over an average of 14 days, making it one of the wetter months of the year. Visitors should be prepared for both heat and occasional downpours as they explore the rich history and stunning landscapes of this vibrant city.
In September, Nagasaki begins to transition from the scorching heat of summer to a more moderate climate. With minimum temperatures lingering around 19°C (66°F) and daytime highs reaching 32°C (90°F), the month maintains a pleasant warmth, making it ideal for outdoor activities. The average temperature of 25°C (77°F) marks a subtle shift as the city prepares for the upcoming autumn months. Compared to the sweltering peaks in July and August, where temperatures reached upwards of 33°C (93°F), September offers a refreshing, balmy atmosphere, encouraging visitors to explore Nagasaki's stunning landscapes and rich history in comfort. This gradual cooling hints at the vivid changes autumn will bring, with temperatures dropping significantly into October.
In September, Nagasaki experiences a notable shift in its rainfall patterns, receiving approximately 225 mm (8.9 inches) of precipitation over 14 days. This reflects a decrease compared to the preceding summer months, where July peaked at an astounding 442 mm (17.4 inches), indicating the tail end of the heavy monsoon season. As the transition into autumn begins, September's rainfall serves as a prelude to milder conditions, yet still maintains significant moisture levels. This month marks an essential balance between lingering summer rains and the drier months to come, as the city's landscape prepares for the vibrant hues of fall.
In September, Nagasaki experiences a notable shift as humidity levels dip to 84%, providing a slight reprieve from the intense moisture of the summer months. This change follows an impressive peak of 97% in July and 94% in August, marking the height of the region's sweltering season. As the year transitions into autumn, the humidity begins to align more closely with the spring months, where averages range from 69% to 79%. This gradual decline in humidity not only signifies the onset of cooler temperatures but also enriches the air with a crispness that invigorates the city's vibrant landscape, setting the stage for the beautiful fall season ahead.
As summer transitions into fall, September in Nagasaki, Japan, maintains an extreme UV Index of 11, similar to the peak levels experienced in the preceding months. With a burn time of just 10 minutes, it’s essential for residents and visitors alike to remain vigilant about sun protection, especially given the ongoing warmth and clear skies. This month mirrors the consistently high UV exposure of the summer, ensuring that sun safety remains a priority. As autumn approaches, a noticeable shift is expected; however, September still demands attention to harmful UV rays. For more detailed information on the UV Index in Nagasaki, check out Nagasaki UV Index.
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September in Nagasaki, Japan, brings a delightful continuation of the summer's warmth, boasting 261 hours of sunshine. This sunny month follows the peak of August, which recorded an impressive 302 hours, highlighting a seasonal trend where summer months bask in abundant sunlight. As the year transitions towards autumn, September maintains a solid average, showcasing a resilient brightness that lingers before the days begin to shorten. The steady sunshine hours from June through September, all exceeding over 260 hours, suggest a vibrant end to the summer, inviting locals and visitors alike to enjoy the lingering warmth and outdoor activities before the cooler months set in.
In Nagasaki, Japan, the chances of enjoying sunny weather in September sit at a moderate 37%, reflecting a slight drop from the early summer months. July and August are particularly overcast, with sun probabilities plunging to 20% and 30%, respectively. Interestingly, as summer fades, the likelihood of clear skies begins to improve, paving the way for a brighter October, which boasts a striking 65% chance of sunshine. This trend suggests that while September may not be the sunniest month, it serves as a transitional period leading towards the clearer days of autumn.
In Nagasaki, Japan, September signals a gentle transition in daylight duration, with the sun gracing the sky for approximately 12 hours each day. This reflects a gradual decrease from the peak of 14 hours observed during the summer months of June and July. As the year progresses, the daylight hours begin to wane, moving from the bright abundance of summer to the soft embrace of autumn. Notably, the daylight in September is a balance between the extended summer days and the shorter ones that follow in October, where it drops back to 11 hours. This rhythmic ebb and flow of light not only marks the changing seasons but also enriches Nagasaki's serene beauty during this time.
In Nagasaki, Japan, the winds tell a captivating seasonal story. As September arrives, the average wind speed settles at a gentle 3.6 m/s (8 mph), reflecting a subtle shift from the more robust breezes of the earlier summer months. The winds have steadily decreased from 4.2 m/s (9 mph) in August, continuing a trend observed through the warmer months, where winds were consistently above 4 m/s. This tranquil September breeze marks a transitional phase, with the air growing more serene as fall approaches. Interestingly, the wind speeds will gradually rise again in November, offering a reminder of the dynamic climate in this picturesque region. The rhythmic ebb and flow of Nagasaki's winds not only highlight the changing seasons but also enhance the city’s unique charm.
Weather in Nagasaki varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Nagasaki, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present contrasting weather experiences. In September, temperatures are considerably warmer, with a minimum of 19°C (66°F) and an average of 25°C (77°F), peaking at a maximum of 32°C (90°F). This month is also quite humid, with an average humidity of 84% and a substantial 225 mm (8.9 in) of precipitation over 14 days. In stark contrast, January sees much cooler temperatures, with a minimum of 0°C (32°F) and an average of 8°C (47°F), reaching a maximum of 18°C (65°F). Additionally, January has significantly less precipitation, totaling 61 mm (2.4 in) over just 8 days and a lower humidity level of 73%. For detailed information on January weather in Nagasaki, visit Nagasaki weather in January.
In September, the weather is warm and humid, with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 32°C (90°F) and an average of 25°C (77°F). The month is also characterized by significant rainfall, amounting to 225 mm (8.9 in) over 14 days, resulting in a high humidity level of 84%. In contrast, February brings much cooler temperatures, with a range from 0°C (33°F) to 17°C (63°F) and an average of only 9°C (48°F). The precipitation in February is lower at 106 mm (4.2 in) over 10 days, accompanied by a reduced humidity level of 69%. For more detailed information on February conditions, you can check out this link: Nagasaki weather in February.
In September, the weather tends to be quite warm, with minimum temperatures around 19°C (66°F) and an average high of 32°C (90°F). However, this month also experiences significant rainfall, totaling 225 mm (8.9 in) over about 14 days, contributing to high humidity levels of 84%. In contrast, March brings a much cooler climate, featuring a minimum temperature of 5°C (41°F) and a max of 20°C (68°F), with an average of 12°C (54°F). Precipitation is lower in March, with about 157 mm (6.2 in) falling over 12 days and a humidity level of 71%. For more specifics about March weather, you can check Nagasaki weather in March.
September and April present distinctly different weather profiles. In September, temperatures are considerably warmer, with average highs reaching around 32°C (90°F) and an average humidity of 84%. This month also experiences more precipitation, totaling 225 mm (8.9 in) over about 14 days. In contrast, April is much cooler, with temperatures ranging from a minimum of 7°C (46°F) to a maximum of 23°C (73°F) and a lower average humidity of 79%. Additionally, April sees less rainfall, with a total of 143 mm (5.6 in) over just 9 days. For more details on April weather in Nagasaki, you can visit Nagasaki weather in April.
In comparing September and May weather, September boasts warmer temperatures, with an average of 25°C (77°F) and a maximum reaching up to 32°C (90°F). In contrast, May offers cooler conditions, averaging 19°C (67°F) with a maximum of 25°C (77°F). Both months experience significant rainfall, with September receiving 225 mm (8.9 in) over 14 days, while May sees slightly more precipitation at 229 mm (9.0 in) across just 11 days. Humidity levels are quite similar, with September at 84% and May slightly higher at 87%. For more detailed information about May weather, you can visit Nagasaki weather in May.
In comparing the weather between September and June, September generally sees slightly warmer temperatures, with averages reaching 25°C (77°F) compared to June's 22°C (73°F). However, June has higher humidity levels at 91% and more precipitation, totaling 272 mm (10.7 in), compared to September's 225 mm (8.9 in). Both months experience rain for about 14 days; however, the intensity of the rain in June may contribute to its heavier precipitation. For more specific information about the weather patterns in June, you can visit Nagasaki weather in June.
In comparing the weather of September and July, it is evident that both months experience warm temperatures, with September's average reaching 25°C (77°F) and July slightly higher at 26°C (79°F). However, September tends to be more pleasant with lower humidity at 84% compared to the higher 97% in July, making July feel more muggy. Additionally, September sees less precipitation, with 225 mm (8.9 in) over 14 days, while July experiences significantly heavier rainfall of 442 mm (17.4 in) across 18 days. For more detailed weather information, you can check Nagasaki weather in July.
In comparing the weather between September and August, September experiences slightly cooler temperatures, with minimums dropping to 19°C (66°F) and average highs around 32°C (90°F), compared to August's minimum of 21°C (69°F) and maximum of 33°C (93°F). Additionally, September sees a decrease in average precipitation, with 225 mm (8.9 in) over 14 days, while August is notably wetter, receiving 326 mm (12.8 in) during the same number of days. Humidity remains high in both months, but August's average of 94% slightly eclipses September’s 84%. For more details on August weather specifics, you can refer to Nagasaki weather in August.
September typically experiences warmer temperatures compared to October, with minimums of 19°C (66°F) and maximums reaching up to 32°C (90°F) in September, while October sees temperatures drop to a minimum of 14°C (57°F) and a maximum of 28°C (83°F). Additionally, September is characterized by significantly higher precipitation, with 225 mm (8.9 in) over 14 days, compared to October’s 117 mm (4.6 in) spread over just 8 days. The humidity also decreases slightly from September's 84% to October’s 79%. For a more detailed look at the weather in October, you can visit Nagasaki weather in October.
In September, the weather is warm and humid, with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 32°C (90°F) and an average of 25°C (77°F). This month experiences significant rainfall, with approximately 225 mm (8.9 in) over 14 days, making it one of the wetter times of the year. In contrast, November brings a much cooler climate, with temperatures falling to a minimum of 8°C (46°F) and averaging around 15°C (60°F). Rainfall is also reduced in November, totaling 81 mm (3.2 in) over just 9 days, and the humidity drops to 75%. For more detailed information, you can check Nagasaki weather in November.
September in Nagasaki is characterized by warm temperatures, with a minimum of 19°C (66°F) and an average of 25°C (77°F), reaching as high as 32°C (90°F). This month experiences significant rainfall, totaling 225 mm (8.9 in) over 14 days, contributing to a high humidity level of 84%. In contrast, December brings a much cooler climate, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 22°C (71°F), averaging around 10°C (51°F). The precipitation decreases to 92 mm (3.6 in) over just 8 days, and humidity levels drop to 72%. For a deeper understanding of what to expect during this winter month, you can check Nagasaki weather in December.
As September unfolds in Nagasaki, it brings a noticeable transition from the heat of summer to milder temperatures, characterized by a comfortable average that invites outdoor exploration. The city's weather is often defined by higher humidity levels and a significant amount of rainfall spread across nearly half the month, setting it apart from the drier summer months. While the warmth lingers with maximum temperatures still in the low thirties, the cooler evenings offer a refreshing contrast. If you're planning a visit or simply want to know more about what to expect, check out Nagasaki Climate for a detailed look at this dynamic season.