September Weather in Yanagawa, Japan

Last updated: August 21, 2025

In Yanagawa, Japan, September ushers in a blend of warm and humid weather, where temperatures peak at a maximum of 34°C (94°F), contributing to an average of 24°C (76°F), and dipping to a refreshing minimum of 13°C (55°F) at night. With substantial precipitation measuring 209 mm (8.2 in) over approximately 15 days, this month is marked by frequent rain showers, leading to a high humidity level of 84%. This combination of warmth and moisture creates a lush and vibrant atmosphere, perfect for experiencing the unique charm of Yanagawa during early autumn.

September Temperature in Yanagawa

In September, Yanagawa experiences a delightful transition as summer gracefully yields to autumn. The minimum temperatures settle at a comfortable 13°C (55°F), while the average climbs to a warm 24°C (76°F), making it an ideal time for outdoor activities. The maximum temperature can reach up to 34°C (94°F), hinting at the lingering warmth of summer days. Compared to the blazing heights of August, which peaks at 36°C (97°F), September offers a more temperate climate, inviting visitors to enjoy the vibrant fall foliage without the oppressive heat. As the month progresses, the cooler evenings beckon the approach of autumn, making this a picturesque time to explore Yanagawa's scenic landscapes.

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

The chart illustrates September temperature patterns in Yanagawa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Yanagawa, 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).
JanFebMarAprMayJunJulAugSepOctNovDec434452596773808275665545
Data source: Temperature data for Yanagawa generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Yanagawa

In September, Yanagawa experiences significant rainfall, with an average precipitation of 209 mm (8.2 in) over 15 days of the month. This marks a notable decrease from the peak rainy season of July, which records a staggering 450 mm (17.7 in) over 19 days, but remains substantial compared to the preceding months. As summer transitions to autumn, the rainfall in September underscores a gradual tapering of the intense monsoon conditions, yet it still contributes to the region's lush landscapes. This consistent rainfall pattern suggests that September serves as a critical bridge, maintaining soil moisture levels while paving the way for the drier months ahead.

September Precipitation Trends in Yanagawa

The chart displays monthly precipitation patterns in Yanagawa, 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 Yanagawa, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec54851331242002334503312091205771
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Yanagawa

In September, Yanagawa, Japan experiences a notable shift in humidity, averaging 84%, which reflects a decrease from the peak summer months of July and August, when levels soared to 92% and 91% respectively. This transition marks the onset of autumn, as humidity levels begin to stabilize after the sweltering heat. The gradual decline from the summer highs suggests a comfortable shift, making September an inviting month for both residents and visitors. However, the humidity remains relatively high compared to the winter months, where levels drop to around 75% in January, creating a lingering sense of moisture in the air that characterizes Yanagawa's unique climate throughout the year.

September Average Humidity in Yanagawa

This chart illustrates the average monthly humidity levels in Yanagawa, 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 Yanagawa is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec75%71%71%78%84%86%92%91%84%83%81%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Yanagawa

In September, Yanagawa, Japan, experiences an extreme UV Index of 11, similar to the peak summer months of July and August. This trend highlights the continued intensity of sun exposure as summer transitions into fall, with a burn time of only 10 minutes for unprotected skin. While the UV levels begin to taper off in October, the sustained high readings in September remind residents and visitors alike to remain vigilant about sun protection throughout this month. Whether you’re enjoying the local sights or simply soaking up the late summer sun, always be mindful of UV risks. For more details, visit Yanagawa UV Index.

Maximum UV Index Levels in Yanagawa for September

The chart shows the monthly maximum UV Index (UVI) for Yanagawa 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 Yanagawa typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468111111121211764
Data source: Yanagawa 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 Yanagawa

In Yanagawa, Japan, September enjoys a delightful 251 hours of sunshine, marking a slight dip from the sun-drenched days of August which boasts an impressive 296 hours. This month transitions gracefully into autumn, featuring a balance of warmth and cooler breezes, as the daylight begins to recede. Notably, with hours of sunshine peaking in July and August, September serves as a gentle reminder of the fading summer, yet still retains a significant amount of bright days. Following this, October holds its own with 254 hours, ensuring that the beautiful golden hues of fall are illuminated by ample sunshine, making this period a picturesque time to explore the captivating scenery of Yanagawa.

Monthly Sunshine Duration in Yanagawa: September Highlighted

The September sunshine duration represents the total number of hours Yanagawa 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.
JanFebMarAprMayJunJulAugSepOctNovDec174h232h260h280h282h260h266h296h251h254h233h213h
Data source: Yanagawa September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Yanagawa During September

In Yanagawa, Japan, the likelihood of sunny weather in September stands at 31%, reflecting a gradual rebound from the summer's gloom. As the sweltering months of July and August feature notably low chances of sunshine at 19% and 25%, respectively, September emerges as a transition point, signaling a slight improvement in clear skies. While the prospects for sunny days are still modest, they are significantly better than the dismal June, which captures only 23% sunshine. This trend sets the stage for a more favorable October, where the likelihood of sun soars to 65%, inviting residents and visitors alike to anticipate warmer, clearer days just around the corner.

Percentage of Sunny Days in September in Yanagawa

The chart illustrates the percentage of sunny days in Yanagawa 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 Yanagawa experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec36%45%35%41%30%23%19%25%31%65%51%45%
Data source: Yanagawa September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Yanagawa in September

As summer fades in Yanagawa, Japan, September sees a gentle decline in daylight, offering around 12 hours of sunlight each day. This month marks a transition from the long, sun-drenched days of July and August, which both boast 14 hours of daylight, to the shorter days of autumn as October approaches with 11 hours. The gradual shift reminds us of the rhythm of the seasons; while September offers more light than the colder months ahead, it begins to embrace the cozy anticipation of fall. Overall, the daylight trend showcases a breathtaking journey from the vibrant brightness of late summer to the subdued charm of early autumn.

Average Daylight Hours in Yanagawa for September

The chart illustrates the variation in daylight duration in Yanagawa 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 58m11h 58m13h13h 51m14h 17m14h 4m13h 19m12h 20m11h 19m10h 26m9h 59m
Data source: Yanagawa daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Yanagawa

As September arrives in Yanagawa, Japan, the average wind speed gently settles at 2.1 m/s (5 mph), reflecting a subtle decline from the summer months. Following a slight uptick in wind activity during July and August, the breezes of early autumn maintain a calmness that is characteristic of this transitional period. It’s notable that the wind speed has remained relatively steady throughout the year, oscillating between 1.6 m/s (3 mph) and 2.9 m/s (6 mph), with many months showing similar averages around 2.5 m/s (6 mph). This consistent pattern invites a peaceful ambiance, perfect for enjoying the picturesque landscapes of Yanagawa as the season shifts.

Average September Wind Speed in Yanagawa

The chart displays monthly wind speed patterns in Yanagawa, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.62.92.52.52.51.62.22.32.1 m/s2.12.22.4
Data source: Yanagawa September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Yanagawa Compares to Other Months

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

In September, the weather is characterized by warm temperatures, with a minimum of 13°C (55°F) and a maximum of 34°C (94°F), creating an average of 24°C (76°F). This month also experiences significant precipitation, averaging 209 mm (8.2 in) over about 15 days, along with high humidity at 84%. In contrast, January brings much colder conditions, with temperatures ranging from a minimum of -4°C (25°F) to a maximum of 17°C (63°F) and an average of just 6°C (43°F). The precipitation is notably lower at 54 mm (2.1 in) over only 7 days, accompanied by lower humidity levels at 75%. For more details on January weather, visit Yanagawa weather in January.

September and February present stark contrasts in weather patterns. In September, temperatures range from a mild 13°C (55°F) at night to a scorching 34°C (94°F) during the day, with an average of 24°C (76°F). This month is also characterized by high humidity at 84% and significant rainfall, accumulating 209 mm (8.2 in) over approximately 15 wet days. In contrast, February experiences much cooler temperatures, dropping as low as -4°C (25°F) at night and peaking at 21°C (70°F) during the day, with a much lower average of 7°C (44°F). Rainfall is also reduced, totaling 85 mm (3.4 in) across about 9 days, and humidity levels are lower at 71%. For a deeper insight into February weather, you can explore Yanagawa weather in February.

In September, the weather is significantly warmer than in March, with average temperatures ranging from a mild 13°C (55°F) at night to a hot 34°C (94°F) during the day. This month also sees higher humidity levels at 84% and substantial rainfall, accumulating 209 mm (8.2 in) over 15 rainy days. In contrast, March experiences much cooler temperatures, with nighttime lows dipping to -2°C (29°F) and daytime highs reaching 22°C (73°F). It is dryer, with only 133 mm (5.2 in) of precipitation over 11 days and a lower humidity of 71%. For more detailed climate information, check out Yanagawa weather in March.

The weather in September is significantly warmer than in April, with average temperatures reaching 24°C (76°F) compared to just 15°C (59°F) in April. September also sees more extreme highs, peaking at 34°C (94°F), while April's maximum is a milder 29°C (84°F). Precipitation is more prevalent in September, with 209 mm (8.2 in) falling over 15 days, in contrast to April’s 124 mm (4.9 in) spread over 9 days. Additionally, humidity levels are slightly higher in September at 84%, compared to 78% in April. This variation highlights the transition from the hot summer months to the cooler spring season. For more details on April weather, you can check Yanagawa weather in April.

In comparing the weather of September and May, both months feature similar humidity levels at 84%, creating a consistently damp atmosphere. However, September tends to be warmer, with average temperatures reaching 24°C (76°F) and highs of 34°C (94°F), compared to May's average of 20°C (68°F) and a maximum of 30°C (86°F). Additionally, while both months experience substantial rainfall, September sees slightly more precipitation at 209 mm (8.2 in) over 15 days, compared to May's 200 mm (7.9 in) over 12 days. For a closer look at weather specifics in Yanagawa during May, visit Yanagawa weather in May.

In comparing the weather between September and June, we find that both months feature similar minimum temperatures, averaging around 13°C (55°F). However, September tends to be slightly warmer overall, with an average temperature of 24°C (76°F) compared to June's 23°C (74°F). Both months experience significant rainfall, with September receiving 209 mm (8.2 in) over 15 days and June slightly wetter with 233 mm (9.2 in) over 14 days. Humidity levels are also comparable, with September at 84% and June slightly higher at 86%. For more specific details about June weather in Yanagawa, you can visit Yanagawa weather in June.

When comparing the weather in September to July, we see distinct differences in temperature and precipitation. September typically experiences lower minimum temperatures, averaging around 13°C (55°F), compared to July's warmer 18°C (64°F). While both months have similar maximum temperatures, July tends to be slightly hotter, with averages peaking at 35°C (95°F) versus September's maximum of 34°C (94°F). However, September is marked by higher humidity levels at 84%, contrasted with July's 92%. Precipitation is notably higher in July, totaling 450 mm (17.7 in) over 19 days, compared to September's 209 mm (8.2 in) over just 15 days. For a more detailed look at July conditions, you can check Yanagawa weather in July.

In comparing the weather between August and September, we can see notable shifts. August experiences a warmer average temperature of 28°C (82°F), with maximums reaching up to 36°C (97°F), making it the hotter month overall. However, September offers cooler temperatures, with an average of 24°C (76°F) and maximums peaking at 34°C (94°F). While August is characterized by higher humidity at 91% and substantial rainfall of 331 mm (13.0 in), September still sees significant precipitation at 209 mm (8.2 in) and slightly lower humidity at 84%. For a detailed look at August's weather patterns, check out Yanagawa weather in August.

September and October showcase a notable transition in weather patterns. September typically features warmer temperatures with a minimum of 13°C (55°F) and average highs reaching up to 34°C (94°F). In contrast, October sees cooler nights with a minimum of 7°C (45°F) and a more temperate average of 19°C (66°F). While September is characterized by higher humidity levels at 84% and significant precipitation of 209 mm (8.2 in) over 15 days, October offers a slight respite with reduced rainfall at 120 mm (4.7 in) across 9 days and a comparable humidity level of 83%. For more detailed insights, you can check Yanagawa weather in October.

In September, the weather is notably warmer, with temperatures ranging from a mild 13°C (55°F) at night to a sweltering peak of 34°C (94°F) during the day, accompanied by high humidity of 84%. This month also sees significant rainfall, with approximately 209 mm (8.2 in) spread over 15 days, making it quite a wet time of year.

In contrast, November brings a marked drop in temperatures, with minimums reaching 0°C (31°F) and an average of 13°C (55°F), peaking at a pleasant 25°C (76°F). The month experiences much less precipitation, totaling around 57 mm (2.2 in) over just 7 days, and slightly lower humidity at 81%. For more detailed weather insights, you can check Yanagawa weather in November.

In September, the weather is characterized by significantly higher temperatures, with average highs reaching 34°C (94°F) and an average humidity of 84%. This month experiences considerable rainfall, totaling 209 mm (8.2 in) over about 15 days, creating a rather humid atmosphere. In contrast, December brings a much cooler climate, with temperatures ranging from a minimum of -2°C (28°F) to a maximum of 22°C (72°F) and an average of 7°C (46°F). The precipitation in December is also lighter, amounting to 71 mm (2.8 in) over just 7 days, and humidity levels modestly decrease to 79%. For more details on December weather, you can visit Yanagawa weather in December.

Compare Yanagawa's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Yanagawa

As September arrives in Yanagawa, the weather begins to shift, offering a refreshing contrast to the scorching summer months. With temperatures averaging a comfortable 24°C (76°F), this transitional month promises relief from the oppressive heat, while still allowing for a few warm days with peak temperatures reaching up to 34°C (94°F). Rainfall is more frequent, as evidenced by 15 days of precipitation bringing a total of 209 mm (8.2 in), creating a lush and vibrant landscape. The high humidity of 84% can make the air feel heavier, but it's this combination of warmth and moisture that breathes life into the environment, making September a unique and dynamic time in Yanagawa. For more detailed insights into the weather throughout the year, visit Yanagawa Climate.