September Weather in Yonakuni, Japan

Last updated: August 21, 2025

September in Yonakuni, Japan offers a warm tropical climate, with maximum temperatures reaching 30°C (87°F) and an average of 28°C (83°F). The month is characterized by a minimum temperature of 25°C (77°F), providing a comfortable, albeit humid, atmosphere with humidity levels averaging 82%. Visitors should be prepared for rain, as the island experiences 16 days of precipitation, totaling 160 mm (6.3 in) of rainfall. This blend of warmth and moisture creates a lush landscape, making it a vibrant time to experience the beauty of Yonakuni.

September Temperature in Yonakuni

In September, Yonakuni, Japan, welcomes the transition from the summer heat with pleasantly warm temperatures. With a minimum of 25°C (77°F) and an average of 28°C (83°F), the month maintains the warmth characterized by the high summer months, though slightly moderated. The maximum temperature peaks at 30°C (87°F), marking a gradual decline from the intense summer highs. This trend is a gentle prelude to the cooler months ahead, with temperatures beginning to drop significantly in October. Overall, September offers a delightful blend of lingering summer vibes and the first hints of autumn, making it an appealing time for visitors and locals alike to enjoy the outdoors.

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

The chart illustrates September temperature patterns in Yonakuni, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Yonakuni, 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).
JanFebMarAprMayJunJulAugSepOctNovDec686871747983848382797570
Data source: Temperature data for Yonakuni 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 Yonakuni

In September, Yonakuni experiences a noticeable decrease in precipitation compared to the peak months of July and August, with an average of 160 mm (6.3 in) of rainfall over 16 days. This decline reflects a seasonal transition as summer gives way to autumn, following the notably wet summer months that saw rain totals reach 221 mm (8.7 in) in August. Interestingly, September's rainfall amounts are consistent with the drier conditions of both April and May, which also recorded 160 mm or less. As the landscape shifts into fall, residents can expect more stable weather patterns, with lower precipitation levels becoming a welcome respite from the summer storms, paving the way for the beautiful autumn hues and clearer skies ahead.

September Precipitation Trends in Yonakuni

The chart displays monthly precipitation patterns in Yonakuni, 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 Yonakuni, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec133141195179180215193221160188195237
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Yonakuni

In September, Yonakuni, Japan experiences a relative dip in humidity, settling at 82% after a summer of consistently high moisture levels. The months preceding September—particularly from May through August—showcase a remarkable peak in humidity, with readings remaining at 84%. This trend reflects the region's tropical climate, where the hot summer months usher in sticky conditions. As autumn approaches, a gradual decline in humidity is observed, with October and November maintaining levels around 81% and 80%, respectively. Thus, September serves as a transitional month, where the lingering warmth of summer begins to give way to the more temperate climes of fall, all while still holding onto a significant amount of moisture in the air.

September Average Humidity in Yonakuni

This chart illustrates the average monthly humidity levels in Yonakuni, 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 Yonakuni is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%74%79%82%84%84%84%83%82%81%81%78%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Yonakuni

In September, the UV Index in Yonakuni, Japan, registers at 12, indicating an extreme exposure category with a burn time of just 10 minutes. This marks a slight decrease from the peak of 13 observed in the preceding months of June through August. Throughout the summer, residents and visitors need to be especially vigilant, as the consistent extreme levels can lead to rapid sunburn. As September rolls in, while there is a slight reduction in UV intensity, precautions should still be taken considering the potential for significant skin damage in a short amount of time. Understanding these trends is crucial for anyone spending time outdoors—be sure to check the latest updates on the Yonakuni UV Index.

Maximum UV Index Levels in Yonakuni for September

The chart shows the monthly maximum UV Index (UVI) for Yonakuni 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 Yonakuni typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec810121313131313121097
Data source: Yonakuni 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 Yonakuni

As summer wanes in Yonakuni, Japan, September boasts an impressive 293 hours of sunshine, continuing the trend of abundant daylight that characterizes the warmer months. Following the peak sunny days of July and August, which recorded 339 and 320 hours respectively, September retains a generous amount of sunshine, ensuring that the warmth lingers just a bit longer. This pleasant decline marks a smooth transition into autumn, with sunlight gradually diminishing as the year heads into October's cooler embrace, which still offers a respectable 259 hours. Overall, September serves as a delightful bridge, allowing residents and visitors alike to bask in the golden light of early fall before cooler days descend upon the island.

Monthly Sunshine Duration in Yonakuni: September Highlighted

The September sunshine duration represents the total number of hours Yonakuni 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.
JanFebMarAprMayJunJulAugSepOctNovDec124h184h249h259h305h295h339h320h293h259h207h166h
Data source: Yonakuni September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Yonakuni During September

September in Yonakuni, Japan, marks a significant shift towards sunnier weather, boasting a 63% chance of sunshine. This notable increase aligns with the gradual transition from the summer months, where the sun is less prominent, with July and August featuring only 24% and 32% chances, respectively. As summer gives way to autumn, September emerges as a standout month, offering one of the highest probabilities for clear skies throughout the year. This trend suggests a welcoming opportunity for outdoor activities and exploration, making it an ideal time to bask in the lingering warmth as the days begin to shorten.

Percentage of Sunny Days in September in Yonakuni

The chart illustrates the percentage of sunny days in Yonakuni 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 Yonakuni experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec16%39%33%36%28%12%24%32%63%34%25%21%
Data source: Yonakuni September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Yonakuni in September

In Yonekuni, Japan, the rhythm of daylight showcases a captivating seasonal cycle that begins with the sun creeping back into the sky in January, offering 10 hours of daylight. As winter gives way to spring, daylight gradually increases, reaching a vibrant 13 hours in May through July. This peak brings plenty of time for outdoor activities and enjoying the lush landscapes. However, as summer wanes, daylight hours begin to retreat, with September maintaining a balanced 12 hours before transitioning into the shorter days of October. This gentle decline continues into winter, where daylight returns to 10 hours by December. The progression of daylight not only marks the changing seasons but also enriches the natural beauty of Yonekuni throughout the year.

Average Daylight Hours in Yonakuni for September

The chart illustrates the variation in daylight duration in Yonakuni throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 47m11h 19m12h12h 43m13h 19m13h 36m13h 27m12h 56m12h 16m11h 33m10h 56m10h 38m
Data source: Yonakuni daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Yonakuni

As summer transitions to autumn in Yonakuni, Japan, September greets us with a gentle decrease in wind speed, averaging 4.7 m/s (11 mph). This subtle shift marks the end of the hottest months, where gusts were slightly stronger, ranging from 5.0 m/s in August to a notable 6.0 m/s in July. Interestingly, September’s breezes are the calmest of the latter half of the year, suggesting a peaceful retreat into the more temperate autumn climate. As the month folds into October, winds pick up again, hinting at nature's rhythm as the seasons change, echoing with 7.3 m/s (16 mph) of fresh vigor that accompanies the onset of fall. This pattern showcases a dynamic interplay of seasons, with September serving as a tranquil bridge before autumn's brisk embrace.

Average September Wind Speed in Yonakuni

The chart displays monthly wind speed patterns in Yonakuni, 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.
JanFebMarAprMayJunJulAugSepOctNovDec8.16.36.16.45.84.16.05.04.7 m/s7.37.58.4
Data source: Yonakuni September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Yonakuni Compares to Other Months

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

September and January present contrasting weather conditions. In September, temperatures are much warmer, with a minimum of 25°C (77°F) and an average of 28°C (83°F), peaking at 30°C (87°F). The month also sees significant rainfall, with 160 mm (6.3 in) spread over 16 days, contributing to a high humidity level of 82%. In contrast, January brings cooler temperatures, with a minimum of 12°C (53°F), an average of 20°C (68°F), and a maximum of 25°C (77°F). While it is drier with 133 mm (5.2 in) of rain over 18 days, humidity is slightly lower at 76%. For more details on January weather, you can visit Yonakuni weather in January.

September and February present contrasting weather patterns. In September, temperatures are significantly warmer, with minimums around 25°C (77°F) and average highs reaching up to 30°C (87°F). This month also experiences higher humidity at 82% and substantial precipitation, averaging 160 mm (6.3 in) over 16 days. In contrast, February brings cooler temperatures, with minimums dropping to 13°C (55°F) and average highs of 25°C (77°F). While February has slightly less rainfall at 141 mm (5.5 in), it is spread over more days, totaling 18. The humidity during this month is also lower at 74%. For more detailed insights on February weather, you can visit Yonakuni weather in February.

In comparing the weather between September and March, September tends to be significantly warmer with average temperatures ranging from a minimum of 25°C (77°F) to a maximum of 30°C (87°F), while March offers cooler conditions, with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 26°C (80°F). Both months experience high humidity, although September is slightly more humid at 82% compared to March's 79%. While September sees considerable rainfall with 160 mm (6.3 in) over 16 days, March receives even more precipitation at 195 mm (7.7 in) across 19 days. For more detailed insights, you can check Yonakuni weather in March.

In comparing the weather patterns of September and April, September boasts a higher average temperature, with a minimum of 25°C (77°F) and an average of 28°C (83°F). In contrast, April features cooler temperatures, starting at a minimum of 17°C (63°F) and peaking at an average of 23°C (74°F). Both months see significant rainfall, with September receiving 160 mm (6.3 in) and April slightly more at 179 mm (7.0 in), though both months have approximately 16 days of precipitation and maintain a high humidity level of 82%. For a closer look at April's climate in particular, check out Yonakuni weather in April.

In comparing the weather of September and May, September boasts slightly warmer temperatures, with a minimum of 25°C (77°F) and an average of 28°C (83°F), while May has a lower minimum of 21°C (70°F) and an average of 26°C (79°F). Both months experience similar humidity levels, with September at 82% and May slightly higher at 84%. However, May sees a bit more precipitation, accumulating 180 mm (7.1 in) over 16 days compared to September's 160 mm (6.3 in) over the same number of days. For more detailed information, check out Yonakuni weather in May.

In comparing the weather between September and June, both months showcase similar temperature ranges, with minimums around 25°C (77°F) and average temperatures of approximately 28°C (83°F). However, June tends to be slightly warmer with a maximum temperature reaching 31°C (87°F), compared to September’s peak of 30°C (87°F). Precipitation levels are notably higher in June, with 215 mm (8.5 in) over 19 days, compared to September's 160 mm (6.3 in) over 16 days. Humidity levels are also slightly elevated in June at 84%, compared to September’s 82%. For more detailed insights, check out Yonakuni weather in June.

September weather closely resembles that of July, with average temperatures only slightly lower—28°C (83°F) in September compared to 29°C (84°F) in July. Both months experience maximum temperatures reaching up to 30°C (87°F). However, September sees a higher amount of rainfall, with 160 mm (6.3 in) compared to July's 193 mm (7.6 in), despite having the same number of rainy days—16. Humidity levels are also slightly lower in September at 82%, compared to July's 84%. For more detailed information, you can check Yonakuni weather in July.

In comparing the weather between August and September, we see that both months maintain warm temperatures, with September showing slightly cooler averages. September's average temperature is 28°C (83°F), while August is a bit warmer at 29°C (84°F). The maximum temperatures are similar, peaking at 30°C (87°F) in September and 31°C (87°F) in August. However, September experiences more rainfall with 160 mm (6.3 in) over 16 days, compared to August's 221 mm (8.7 in) over 19 days. Humidity levels remain quite high in both months, with September at 82% and August slightly higher at 83%. For more detailed insights into August weather, check Yonakuni weather in August.

September and October exhibit a transition in weather patterns. In September, temperatures range from a minimum of 25°C (77°F) to a maximum of 30°C (87°F), with an average of 28°C (83°F). The month sees substantial rainfall, with a total of 160 mm (6.3 in) spread over 16 days, and humidity remains high at 82%. In contrast, October experiences slightly cooler temperatures, with a minimum of 21°C (71°F) and a maximum of 29°C (85°F), averaging 26°C (79°F). The month is wetter, with 188 mm (7.4 in) of precipitation over 18 days and a marginally lower humidity of 81%. For a detailed look at the weather specifics, you can refer to Yonakuni weather in October.

In September, the weather is warm with temperatures ranging from a minimum of 25°C (77°F) to a maximum of 30°C (87°F), averaging around 28°C (83°F). However, this month also experiences significant rainfall, with 160 mm (6.3 in) spread over 16 days and high humidity at 82%. In contrast, November brings cooler temperatures, with a range from 20°C (68°F) to 27°C (81°F), averaging 24°C (76°F). This month sees even greater precipitation, totaling 195 mm (7.7 in) over 23 days, accompanied by slightly lower humidity at 80%. For a detailed look at what to expect during this month, check out Yonakuni weather in November.

September weather is characterized by warm temperatures, with a minimum of 25°C (77°F), an average of 28°C (83°F), and a maximum of 30°C (87°F). The month experiences considerable rainfall, with 160 mm (6.3 in) spread over 16 days and a high humidity level of 82%. In contrast, December brings cooler weather, with a minimum of 13°C (56°F), an average of 21°C (71°F), and a maximum of 26°C (78°F). While precipitation increases to 237 mm (9.3 in) over 24 days, the humidity drops slightly to 78%. Overall, December offers a more temperate climate compared to the hot, humid conditions of September. For more information, check out Yonakuni weather in December.

Compare Yonakuni's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Yonakuni

September in Yonakuni brings a noticeable transition in weather, characterized by warm temperatures and increased rainfall compared to the summer months. With an average temperature hovering around 28°C (83°F), the air feels balmy and humid, often reaching up to 30°C (87°F) during the day. The high humidity of 82% coupled with 160 mm of precipitation spread over 16 days makes this month particularly wet, ushering in a lush vibrancy to the landscape. While you can still bask in the warmth, September marks a shift towards a more tropical climate, paving the way for the upcoming autumn season. To learn more about how Yonakuni's weather varies throughout the year, check out Yonakuni Climate.