September Weather in Sasebo, Japan

Last updated: August 21, 2025

September in Sasebo, Japan, offers a warm embrace, with maximum temperatures soaring to a sultry 34°C (94°F) and an average hovering around a comfortable 25°C (77°F). The nights provide a refreshing balance with temperatures dropping to a minimum of 17°C (63°F). This month is notable for its significant rainfall, accumulating to 222 mm (8.7 in) over 15 days, contributing to an average humidity level of 84%. Visitors can expect a mix of warm days ideal for exploring, alongside refreshing showers that nourish the lush surroundings.

September Temperature in Sasebo

As September arrives in Sasebo, Japan, the temperatures begin to cool from the sweltering summer months, yet warmth remains abundant. With a minimum temperature of 17°C (63°F) and an average of 25°C (77°F), it’s a month that invites both outdoor exploration and relaxation. The maximum reaches a sizzling 34°C (94°F), hinting at the lingering summer vibes before autumn sets in. This transition period not only provides a comfortable climate for activities like sightseeing or enjoying local cuisine by the waterfront but also showcases the beauty of nature as the leaves start to hint at their upcoming changes. Thus, September offers a delightful balance—melding summer’s warmth with the first whispers of autumn, making it a captivating time to visit Sasebo.

September Weather in Sasebo: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Sasebo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sasebo, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec464754606873808377685849
Data source: Temperature data for Sasebo generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Sasebo

In September, Sasebo experiences a notable increase in precipitation, receiving 222 mm (8.7 in) of rain over 15 days. This marks a gradual decrease from the summer months, particularly following July's peak of 361 mm (14.2 in). The lushness of early autumn contrasts with the heavy rains faced in the height of summer, as September positions itself as a transitional month. The rainfall in September is substantial, yet it reflects a shift towards drier conditions as the city heads into October, where only 109 mm (4.3 in) is recorded over 9 days. This rainfall pattern highlights the region's humid subtropical climate, where the lingering impacts of summer storms gradually give way to a more temperate fall environment.

September Precipitation Trends in Sasebo

The chart displays monthly precipitation patterns in Sasebo, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Sasebo, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec57791321141682003612882221095174
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Sasebo

In Sasebo, Japan, September marks a shift in humidity as summer fades into autumn, with levels sitting at a substantial 84%. This month showcases a noticeable drop from the peak of 97% in July, transitioning through the sultry summer months. As the year progresses, September’s humidity is significant yet less oppressive compared to the intensity experienced in the heart of summer. Moving forward, the levels are anticipated to decrease further into October, bringing a more comfortable atmosphere with 79% humidity. Overall, the progression from high summer to early autumn illustrates a gradual easing, inviting a refreshing change after the humid highs.

September Average Humidity in Sasebo

This chart illustrates the average monthly humidity levels in Sasebo, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Sasebo is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec73%69%71%79%87%92%97%94%84%79%75%72%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Sasebo

As summer fades into September, Sasebo, Japan, experiences a slight dip in UV intensity, yet the UV Index remains at a formidable 11, signaling an extreme exposure category. With a burn time of just 10 minutes, it's clear that sun safety remains a top priority. This month mirrors the relentless UV levels seen in the peak summer months of July and August, which also registered an Index of 12. Interestingly, prior to September, UV levels have steadily climbed since January, reflecting an upward trend through the spring and summer seasons. As you navigate the sun-filled days of September, don’t forget to prioritize protection and stay informed by checking the latest details at Sasebo UV Index.

Maximum UV Index Levels in Sasebo for September

The chart shows the monthly maximum UV Index (UVI) for Sasebo in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Sasebo typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121211764
Data source: Sasebo September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Sasebo

In September, Sasebo, Japan, basks in a soothing blend of summer's warmth and autumn's gentle arrival, boasting 258 hours of sunshine. This marks a significant drop from the sun-drenched peak of 306 hours enjoyed in August, yet it still exceeds the 236 hours seen in November, showcasing a graceful transition into fall. The overall trend reveals that as the year progresses, Sasebo typically experiences its most radiant months in the summer, with a gradual decline in sunshine hours leading into winter. Thus, September serves as a beautiful bridge between the exuberant brightness of summer and the softer light of the cooler months ahead.

Monthly Sunshine Duration in Sasebo: September Highlighted

The September sunshine duration represents the total number of hours Sasebo experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec168h227h264h284h288h274h287h306h258h258h236h198h
Data source: Sasebo September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Sasebo During September

In Sasebo, Japan, the chance of sunny weather in September stands at a moderate 33%, marking a slight uptick from the summer months where sunshine is notably less frequent. With July and June recording the lowest probabilities at just 20% and 25%, respectively, September offers a refreshing shift as the region transitions into autumn. While not the sunniest month on record, September’s forecast reflects a balance in weather patterns, hinting at a mix of sun and clouds. As we look forward, the likelihood of brighter days surges dramatically into October, reaching a remarkable 62%, suggesting that the warmth of late summer still lingers, inviting outdoor activities and exploration before the cool autumn sets in.

Percentage of Sunny Days in September in Sasebo

The chart illustrates the percentage of sunny days in Sasebo throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Sasebo experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec34%44%36%40%32%25%20%29%33%62%50%40%
Data source: Sasebo September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Sasebo in September

As September unfolds in Sasebo, Japan, daylight begins to wane, offering about 12 hours of sunlight each day. This shift marks a gradual transition from the longer summer days, which peak in July and June with 14 hours of daylight. Following the vibrant months of June and July, where hours in the sun are at their maximum, August slightly tapers off to 13 hours, hinting at the upcoming changes of autumn. As we move into October, daylight further decreases to 11 hours—a reminder of the shortening days ahead. This gradual decline in daylight not only reflects the seasonal shift but also sets the stage for the cozy ambiance of fall, inviting residents to embrace the changing atmosphere.

Average Daylight Hours in Sasebo for September

The chart illustrates the variation in daylight duration in Sasebo throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 12m10h 59m11h 58m13h13h 51m14h 17m14h 4m13h 19m12h 20m11h 19m10h 26m9h 59m
Data source: Sasebo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Sasebo

As September unfolds in Sasebo, Japan, the average wind speed settles at 3.0 m/s (7 mph), marking a slight dip from the summer months. This seasonal transition reveals a gentle retreat from the warmer breezes of August, where winds were a bit more spirited at 3.1 m/s (7 mph). The trend of diminishing wind speeds continues into the autumn, as the region prepares for the cooler days ahead. Notably, September's winds contribute to a serene atmosphere, perfect for enjoying the enchanting landscapes as nature begins to shift colors. The gradual decline in wind speed from spring's peak of 3.7 m/s (8 mph) reminds us that Sasebo's climate evolves gracefully, blending warmth with the anticipation of crisp fall air.

Average September Wind Speed in Sasebo

The chart displays monthly wind speed patterns in Sasebo, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.04.03.73.53.22.42.93.13.0 m/s2.93.43.8
Data source: Sasebo September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Sasebo Compares to Other Months

Weather in Sasebo varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sasebo, focusing on differences in temperature, rainfall, humidity, and UV levels.

September and January present a stark contrast in weather conditions. September features warm temperatures, with averages around 25°C (77°F) and highs soaring up to 34°C (94°F), while humidity remains high at 84%. However, it also brings substantial rainfall, averaging 222 mm over approximately 15 days. In contrast, January offers a much cooler climate, with average temperatures around 8°C (46°F) and a maximum of 18°C (66°F). Precipitation is significantly lower at 57 mm over just 7 days, and humidity is also reduced to 73%. For more detailed information on January weather, check out Sasebo weather in January.

Comparing the weather in September and February reveals a striking contrast in both temperature and precipitation. September typically boasts warmer temperatures, ranging from a mild minimum of 17°C (63°F) to a scorching maximum of 34°C (94°F), along with high humidity at 84%. However, this month also experiences significant rainfall, with an average of 222 mm (8.7 in) over 15 days.

In contrast, February is much cooler, featuring a minimum temperature of -1°C (30°F) and a maximum of 21°C (70°F), leading to an average temperature of only 8°C (47°F). Precipitation drops significantly to 79 mm (3.1 in) across just 9 days, accompanied by lower humidity at 69%. For more detailed insights about February weather, you can visit Sasebo weather in February.

In comparing the weather of September and March, notable differences in temperature and humidity stand out. September experiences warmer temperatures, with a minimum of 17°C (63°F) and an average of 25°C (77°F), peaking at a maximum of 34°C (94°F). The month also sees high humidity levels of 84% and significant rainfall, totaling 222 mm (8.7 in) over approximately 15 days. In contrast, March offers a much cooler climate, with temperatures ranging from a minimum of 2°C (37°F) to an average of 12°C (54°F), and a maximum of 23°C (73°F). Precipitation is lower in March, at 132 mm (5.2 in) over about 10 days, coupled with a decreased humidity level of 71%. For a more detailed look at March weather specifically in Sasebo, you can check Sasebo weather in March.

September and April present distinct weather contrasts. In September, temperatures range from a minimum of 17°C (63°F) to a scorching maximum of 34°C (94°F), with an average of 25°C (77°F). This month also sees significant precipitation, totaling 222 mm (8.7 in) over 15 rainy days and a high humidity level of 84%. In contrast, April records milder temperatures with a minimum of 6°C (42°F), an average of 16°C (60°F), and a maximum of 27°C (82°F). The rain is less frequent, accumulating to 114 mm (4.5 in) over only 9 days, and humidity stands at a comfortable 79%. For a more detailed look at April's climate, visit Sasebo weather in April.

When comparing the weather in September and May, it's clear that September is considerably warmer, with average temperatures ranging from a minimum of 17°C (63°F) to a maximum of 34°C (94°F). In contrast, May offers cooler temperatures, with a range from 9°C (48°F) to 28°C (83°F). Both months experience notable humidity levels, with September at 84% and May slightly higher at 87%. Precipitation is also more prominent in September, receiving 222 mm (8.7 in) over 15 days, compared to May's 168 mm (6.6 in) across just 11 days. For more detailed information about May weather, check out Sasebo weather in May.

September and June exhibit distinct weather patterns, with September generally being warmer and wetter. In September, temperatures range from a minimum of 17°C (63°F) to a maximum of 34°C (94°F), with an average of 25°C (77°F). The month also sees substantial rainfall, totaling 222 mm (8.7 in) over 15 days and a humidity level of 84%. In contrast, June presents slightly cooler temperatures, with a minimum of 16°C (61°F) and a maximum of 31°C (89°F), averaging 23°C (74°F). Rainfall in June is slightly less, at 200 mm (7.9 in) over 12 days, coupled with a higher humidity of 91%. For a closer look at June's specific conditions, refer to Sasebo weather in June.

In comparing the weather of September and July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 17°C (63°F) to a maximum of 34°C (94°F), while July is warmer, with temperatures ranging from a minimum of 19°C (66°F) to a maximum of 36°C (96°F). July experiences higher humidity, peaking at 97% compared to September's 84%. Additionally, September sees significantly less precipitation at 222 mm (8.7 in) over 15 days, compared to July’s 361 mm (14.2 in) over 18 days. For more detailed information, you can check Sasebo weather in July.

In comparing the weather of September and August, September experiences slightly cooler temperatures, with a minimum of 17°C (63°F) and an average of 25°C (77°F), compared to August's minimum of 20°C (68°F) and an average of 28°C (83°F). August peaks with a higher maximum temperature of 37°C (99°F), while September tops out at 34°C (94°F). Additionally, September has lower overall precipitation, recording 222 mm (8.7 in) over 15 days, whereas August sees 288 mm (11.3 in) across the same number of days. Humidity levels also decrease in September, averaging 84%, compared to August's 94%. For more detailed information, you can check Sasebo weather in August.

In September, the weather is characterized by higher temperatures, with a minimum of 17°C (63°F) and an average of 25°C (77°F), peaking at a sweltering 34°C (94°F). This month sees significant rainfall, accumulating 222 mm (8.7 in) over 15 days, coupled with high humidity levels of 84%.

In contrast, October experiences a noticeable drop in temperature, with lows of 11°C (51°F) and an average of 20°C (68°F), while the maximum temperature reaches 31°C (88°F). The total precipitation decreases to 109 mm (4.3 in) over just 9 days, and humidity levels slightly lower to 79%. For more detailed insights, check out Sasebo weather in October.

In September, the weather is warm, with temperatures ranging from a mild 17°C (63°F) at night to a hot 34°C (94°F) during the day, and an average temperature of 25°C (77°F). This month also experiences high humidity at 84% and considerable rainfall, totaling 222 mm (8.7 in) over approximately 15 days. In contrast, November brings a significant drop in temperatures, with nighttime lows of 4°C (40°F) and daytime highs reaching 25°C (77°F), averaging at 15°C (58°F). Additionally, November sees much less rainfall, with only 51 mm (2.0 in) over about 7 days, and a slightly lower humidity level of 75%. For more detailed information, you can check Sasebo weather in November.

In September, the weather is characterized by warm temperatures, with a minimum of 17°C (63°F) and averages reaching up to 25°C (77°F), peaking at 34°C (94°F). This month also sees significant precipitation, with 222 mm (8.7 in) spread over 15 days, and a high humidity level of 84%, creating a muggy atmosphere. In contrast, December experiences much cooler temperatures, with a minimum of just 1°C (33°F) and an average of 9°C (49°F), while maximums reach 23°C (74°F). Precipitation decreases significantly to 74 mm (2.9 in) over only 7 days, and humidity drops to 72%, resulting in a drier and crisper climate. For more detailed information, you can visit Sasebo weather in December.

Compare Sasebo's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Sasebo

As September arrives in Sasebo, it marks a transition from the sweltering summer heat, featuring higher humidity and a notable increase in rainfall. With average temperatures hovering around a comfortable 25°C, this month is cooler than the peak summer months, yet still sees occasional spikes up to 34°C. The increased precipitation, with about 15 rainy days throughout the month, creates a more lush and vibrant landscape, setting September apart from the drier, hotter days of July and August. For a more comprehensive look at the year-round weather patterns in Sasebo, visit Sasebo Climate.