September Weather in Rusutsu, Japan

Last updated: August 21, 2025

September in Rusutsu, Japan offers a mild climate with temperatures ranging from a maximum of 28°C (83°F) to a comfortable average of 17°C (62°F), dipping to a refreshing minimum of 4°C (39°F) during cooler nights. This month sees significant rainfall, totaling 116 mm (4.6 in) over approximately 14 days, contributing to the region's lush landscapes. With humidity levels reaching a notable 88%, the air carries a crisp freshness, making it an ideal time for visitors to explore the breathtaking scenery and vibrant autumn foliage.

September Temperature in Rusutsu

September in Rusutsu, Japan, marks a delightful transition from the warmth of summer to the crispness of autumn. With temperatures ranging from a pleasant 4°C (39°F) at night to a comfortable 28°C (83°F) during the day, this month offers a perfect blend for outdoor adventures. The average temperature settles at 17°C (62°F), inviting visitors to enjoy the stunning fall foliage and breathtaking views. As the summer heat recedes, September's weather sets the stage for crisp evenings and temperate days, making it an ideal time for hiking and exploring the natural beauty of this alpine paradise before the winter chill descends.

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

The chart illustrates September temperature patterns in Rusutsu, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rusutsu, 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).
JanFebMarAprMayJunJulAugSepOctNovDec212332415359686962513825
Data source: Temperature data for Rusutsu 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 Rusutsu

September in Rusutsu, Japan, ushers in a notable shift in precipitation patterns, with 116 mm (4.6 in) of rainfall recorded over 14 days. This volume marks a slight dip from August's substantial 147 mm (5.8 in), but it still indicates a robust water supply as the region transitions into autumn. Interestingly, this month typically maintains a consistent level of precipitation, aligning closely with October and November, both at 115 mm (4.5 in) and 116 mm (4.6 in), respectively. As summer fades and the weather cools, the frequency of rainy days tends to increase, culminating in 20 days of rainfall in November. This trend highlights a resilience of moisture in the region, setting a picturesque scene as the vibrant autumn foliage begins to emerge against the backdrop of gentle rains.

September Precipitation Trends in Rusutsu

The chart displays monthly precipitation patterns in Rusutsu, 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 Rusutsu, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec64698993871129814711611511686
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Rusutsu

In September, Rusutsu, Japan, experiences a notable drop in humidity, averaging 88%. This marks a shift from the peak summer months of July and August, where humidity levels soar to 93% and 95%, respectively. As autumn approaches, the air becomes slightly drier, yet still retains a substantial moisture content. Following September, humidity levels continue to decline, reaching a more comfortable 83% in October. This pattern highlights a gradual transition from the warm, humid summer to the cooler, more refreshing autumn, creating a pleasant atmosphere for both residents and visitors alike.

September Average Humidity in Rusutsu

This chart illustrates the average monthly humidity levels in Rusutsu, 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 Rusutsu is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%83%81%81%86%87%93%95%88%83%79%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Rusutsu

As summer transitions to autumn in Rusutsu, Japan, September maintains a very high UV Index of 8, necessitating careful sun protection with a burn time of just 15 minutes. This trend reflects the lingering intensity of sun exposure typical of the preceding months, where the UV Index peaked at 10 during the summer. Despite the decrease from peak summer levels, the UV radiation remains significant, reminding outdoor enthusiasts to be vigilant. Notably, October marks a dip to a high UV Index of 6, reinforcing the gradual shift toward lower sun exposure in the coming months. For more detailed information about UV levels throughout the year, visit Rusutsu UV Index.

Maximum UV Index Levels in Rusutsu for September

The chart shows the monthly maximum UV Index (UVI) for Rusutsu 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 Rusutsu typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec236791010108632
Data source: Rusutsu 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 Rusutsu

As summer gracefully transitions into autumn, September in Rusutsu, Japan, enjoys a remarkable 270 hours of sunshine, embodying the last gleams of warm weather. This month sees a slight decline in sunlit hours compared to the sun-filled heights of July, which boasts an impressive 313 hours. What’s striking is the steady increase in sunshine leading up to September, with March kicking off the year at just 248 hours and slowly rising through the spring and summer months. The gentle descent into autumn is not only a celebration of lingering daylight but also a reminder of the cyclical beauty of nature, as the region prepares to embrace the crispness of October with its 236 hours, heralding the upcoming change in seasons.

Monthly Sunshine Duration in Rusutsu: September Highlighted

The September sunshine duration represents the total number of hours Rusutsu 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.
JanFebMarAprMayJunJulAugSepOctNovDec135h192h248h288h307h298h313h289h270h236h182h167h
Data source: Rusutsu September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Rusutsu During September

In Rusutsu, Japan, the likelihood of sunny weather in September stands at 32%, which reflects a modest increase compared to the summer months. While July and August see a slightly higher chance of sunshine at 38% and 27% respectively, September returns to a more transitional climate as autumn begins to set in. This shift is echoed by the gradual rise in sunny days from the colder months earlier in the year, where chances hover around 25% to 27%. As the vibrant hues of early autumn emerge, September offers a refreshing window of opportunity for outdoor activities against a backdrop of stunning fall foliage, making it a delightful time to explore the beauty of Rusutsu.

Percentage of Sunny Days in September in Rusutsu

The chart illustrates the percentage of sunny days in Rusutsu 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 Rusutsu experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%25%32%41%26%43%38%27%32%35%35%30%
Data source: Rusutsu September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Rusutsu in September

As summer fades into autumn, September in Rusutsu, Japan, marks a gentle transition with an average daylight duration of 12 hours. This month sees daylight slightly dwindling from the more abundant 14 hours in May and June, as nature prepares for the shorter days to come. The overall trend throughout the year displays a gradual increase in sunlight hours from January’s 9 hours to the peak of 15 hours in June, before tapering off as the seasons change. By the time the leaves begin to turn and the air crispens, September’s daylight serves as a reminder of the lush summer days now giving way to the tranquility of fall.

Average Daylight Hours in Rusutsu for September

The chart illustrates the variation in daylight duration in Rusutsu throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 24m10h 31m11h 56m13h 23m14h 37m15h 15m14h 56m13h 51m12h 27m11h 1m9h 44m9h 4m
Data source: Rusutsu daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Rusutsu

In September, Rusutsu, Japan, experiences a gentle breeze, with an average wind speed of 2.1 m/s (5 mph). This marks a continuation of the calm winds typical of summer, which hover around similar speeds. Interestingly, as the seasons transition into autumn, the wind patterns reveal a slight decline compared to the preceding months, echoing the overall trend of diminishing wind speeds from the summer’s peak. Despite this subtle drop, the air remains refreshingly crisp, perfectly complementing the scenic beauty of the changing foliage, making September a delightful month to embrace the outdoors in this picturesque region.

Average September Wind Speed in Rusutsu

The chart displays monthly wind speed patterns in Rusutsu, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.73.02.62.82.52.12.12.22.1 m/s2.22.72.7
Data source: Rusutsu September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Rusutsu Compares to Other Months

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

September and January present starkly contrasting weather conditions. In September, temperatures range from a cool 4°C (39°F) at night to a warm 28°C (83°F) during the day, with an average of 17°C (62°F). This month is marked by high humidity at 88% and significant precipitation of 116 mm (4.6 in) over 14 days. In contrast, January brings frigid temperatures, with minimums plunging to -20°C (-4°F) and a maximum of only 4°C (39°F), averaging -6°C (22°F). The precipitation decreases to 64 mm (2.5 in), occurring over 15 days, and humidity is slightly lower at 84%. The differences in temperature and moisture levels highlight the dramatic seasonal transition. For more detailed information, check out Rusutsu weather in January.

September and February showcase strikingly contrasting weather patterns. In September, temperatures range from a mild minimum of 4°C (39°F) to a warm maximum of 28°C (83°F), accompanied by an average of 17°C (62°F). This month sees substantial rainfall, with 116 mm (4.6 in) spread over 14 days, contributing to a notably high humidity of 88%. In sharp contrast, February brings much colder conditions, with temperatures plummeting to a minimum of -17°C (1°F) and only reaching a maximum of 7°C (45°F). The average temperature in February is a frigid -5°C (23°F), while precipitation is lower at 69 mm (2.7 in) but occurs over 18 days. The humidity also decreases slightly to 83%. For more insights into the winter weather, you can explore Rusutsu weather in February.

In comparing the weather of September and March, we see notable contrasts in temperature and conditions. September boasts a milder climate, with average temperatures ranging from a minimum of 4°C (39°F) to a comfortable maximum of 28°C (83°F), accompanied by high humidity at 88%. In contrast, March experiences much colder temperatures, with averages around 0°C (32°F), ranging from a frigid minimum of -13°C (10°F) to a maximum of 13°C (56°F). Although both months see precipitation on about 14 days, September typically receives more rainfall at 116 mm (4.6 in), compared to March's 89 mm (3.5 in). For a detailed look at the conditions in March, you can check Rusutsu weather in March.

September and April present contrasting weather patterns. In September, temperatures range from a cooler minimum of 4°C (39°F) to a warm average of 17°C (62°F) and a maximum of 28°C (83°F), creating a much milder atmosphere. This month also experiences significant precipitation, with 116 mm (4.6 in) falling over 14 days, contributing to a high humidity level of 88%. In contrast, April is characterized by colder conditions, with temperatures dipping as low as -6°C (22°F) and reaching an average of 5°C (41°F), peaking at 19°C (67°F). Although April has less rainfall, at 93 mm (3.7 in) over 12 days, the humidity is slightly lower at 81%. For a more detailed look at the specifics of April weather, you can visit Rusutsu weather in April.

September and May exhibit notable differences in weather patterns. September boasts a wider temperature range, with minimums of 4°C (39°F) and maximums reaching 28°C (83°F), while May tends to be cooler overall, with minimums around 2°C (35°F) and maximums peaking at 29°C (84°F). Precipitation levels also differ, as September receives 116 mm (4.6 in) over 14 days, compared to May's 87 mm (3.4 in) across 12 days. Despite these variations, both months maintain high humidity levels, with September at 88% and May a close 86%. For more detailed information on May weather, you can refer to Rusutsu weather in May.

September and June present notably similar weather patterns, yet there are some distinct differences. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), with an average temperature of 17°C (62°F). The month typically experiences greater rainfall, with 116 mm (4.6 in) of precipitation over about 14 days and an average humidity of 88%. In contrast, June boasts a slightly cooler temperature range of 3°C (38°F) to 26°C (79°F), with an average of 15°C (59°F) and slightly less precipitation at 112 mm (4.4 in) spread across about 11 days and a humidity level of 87%. Both months showcase a damp, cool climate, but September tends to be warmer and wetter. For further details on June weather, visit Rusutsu weather in June.

When comparing the weather in September to that of July, a noticeable shift occurs in temperature and precipitation patterns. September experiences a wider temperature range, with a minimum of 4°C (39°F) and a maximum of 28°C (83°F), averaging around 17°C (62°F). In contrast, July is warmer, boasting a minimum of 11°C (51°F) and a maximum of 31°C (89°F), with an average temperature of 20°C (68°F). Although July has slightly less precipitation at 97 mm (3.8 in) over 12 days compared to September's 116 mm (4.6 in) over 14 days, it is also slightly more humid, with humidity levels at 93% compared to September's 88%. For those interested in more detailed weather information, you can refer to Rusutsu weather in July.

When comparing the weather in September to August, we notice a mild drop in temperatures. September's temperatures range from a minimum of 4°C (39°F) to a maximum of 28°C (83°F), averaging around 17°C (62°F). In contrast, August boasts warmer temperatures, with a minimum of 8°C (47°F), an average of 20°C (69°F), and a peak of 32°C (89°F). Additionally, September experiences slightly less precipitation at 116 mm (4.6 in) over 14 days, compared to August's 147 mm (5.8 in) over 13 days. Humidity in September is also lower at 88%, compared to August's 95%. For more detailed information, you can visit Rusutsu weather in August.

September typically offers a more moderate climate, with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 28°C (83°F). It sees higher humidity levels at 88% and considerable precipitation, with 116 mm (4.6 in) over 14 days. In contrast, October marks a noticeable drop in temperatures, with averages between -2°C (29°F) and 24°C (75°F). Although October has slightly less total precipitation at 115 mm (4.5 in) spread over 15 days, the humidity decreases to 83%. For more details on the weather in October, check out Rusutsu weather in October.

September and November present contrasting weather conditions, with September showcasing a more temperate climate. In September, temperatures range from a minimum of 4°C (39°F) to a pleasant maximum of 28°C (83°F), accompanied by high humidity levels at 88%. This month experiences about 116 mm (4.6 in) of precipitation over 14 days, making it relatively wet but still suitable for outdoor activities.

Conversely, November brings a significant drop in temperatures, with a minimum of -12°C (11°F) and an average of just 3°C (39°F). Although the total precipitation remains the same at 116 mm (4.6 in), it occurs over 20 days, suggesting a more persistent pattern of wet weather. The humidity in November also decreases to 79%, reflecting the colder and crisper air. For those interested in exploring the weather specifics of November, more details can be found at Rusutsu weather in November.

In comparing the weather of September and December, a stark contrast emerges. September typically experiences milder temperatures, ranging from a chilly minimum of 4°C (39°F) to a pleasant average of 17°C (62°F) and reaching a maximum of 28°C (83°F). This month also sees considerable precipitation, with about 116 mm (4.6 in) over 14 days and humidity levels at a high 88%. In contrast, December brings a much colder climate, where temperatures plummet to a minimum of -17°C (2°F), an average of -4°C (25°F), and a maximum of just 11°C (51°F). Although December has lower total precipitation at 86 mm (3.4 in), it occurs over more days, with rain or snow on 24 occasions, and humidity drops slightly to 80%. For those looking to explore conditions in December, detailed information can be found here: Rusutsu weather in December.

Compare Rusutsu's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Rusutsu

As September arrives in Rusutsu, the weather shifts into a transitional phase characterized by milder temperatures and increased humidity compared to the scorching summer months. With average daytime highs reaching a comfortable 17°C (62°F), the air feels cooler and more refreshing, making it an ideal time for outdoor activities. However, frequent rainfall marks this month, as evidenced by the 14 days of precipitation contributing to a total of 116 mm (4.6 in), creating a lush, vibrant landscape. The blend of cooler temperatures and heightened moisture offers a unique atmosphere, distinctly setting September apart from the drier, warmer weeks of summer. For a deeper understanding of what to expect, explore more on the Rusutsu Climate.