September Weather in Hakone, Japan

Last updated: August 21, 2025

In September, Hakone, Japan, experiences a dynamic climate characterized by a maximum temperature reaching up to 33°C (91°F) and a comfortable average of 22°C (72°F). With minimum temperatures dropping to 13°C (56°F), visitors can expect a refreshing range of weather throughout the month. However, rainfall is significant, as the region sees 242 mm (9.5 in) of precipitation over approximately 21 days, contributing to the lush scenery that Hakone is famous for. The high humidity level of 86% adds to the moist atmosphere, making it a captivating time for nature lovers to explore the stunning landscapes, albeit with an umbrella in hand!

September Temperature in Hakone

As September unfolds in Hakone, Japan, the temperature begins to hint at the transitioning seasons. With a minimum of 13°C (56°F) and an average that pleasantly sits at 22°C (72°F), residents and visitors alike enjoy a refreshing reprieve from the summer heat. The daytime highs can reach a balmy 33°C (91°F), making this a wonderful time for outdoor exploration. Compared to the sizzling temperatures of August, which frequently topped 35°C (95°F), September offers a more comfortable climate. As the month progresses, the crispness of autumn starts to creep in, leading to a gradual decline in temperatures as the region prepares for the cooler months ahead. Overall, September in Hakone provides a delightful balance of warmth and coolness, perfect for soaking in the natural beauty of this serene destination.

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

The chart illustrates September temperature patterns in Hakone, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hakone, 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).
JanFebMarAprMayJunJulAugSepOctNovDec394147546368757971625344
Data source: Temperature data for Hakone 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 Hakone

In September, Hakone, Japan experiences a notable surge in precipitation, with 242 mm (9.5 in) of rain falling over 21 days. This pattern of increased rainfall follows the hefty downpours seen in the preceding months, particularly July and June, which are typically the wettest periods of the year. As summer transitions into autumn, the rain not only enhances the lush green landscapes but also sets the stage for picturesque fall foliage. Interestingly, while September sees a dip in total rain compared to October's projected high of 360 mm (14.2 in), it maintains a consistent frequency of precipitation days, indicating a steady rhythm of rain that characterizes this transitional month. This blend of frequent showers and milder temperatures creates a dynamic atmosphere in Hakone, perfect for experiencing the region's natural beauty.

September Precipitation Trends in Hakone

The chart displays monthly precipitation patterns in Hakone, 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 Hakone, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec698320217318023432119824236010279
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hakone

September in Hakone, Japan, brings a noticeable transition in humidity levels, settling at a comfortable 86%. This figure follows the peak of summer, where July and August boast unusually high humidity levels of 93% and 90%, respectively. As the month unfolds, humidity begins to decline gently, yet it remains significantly elevated compared to the earlier months of the year, with values dipping from 74% in February to a mid-range 81% in May. The gradual drop from the steamy summer months indicates the onset of autumn, while still keeping a touch of the lingering warmth and moisture that characterizes the region's climate. As October approaches, we can expect further easing of humidity, emphasizing September's transitional essence.

September Average Humidity in Hakone

This chart illustrates the average monthly humidity levels in Hakone, 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 Hakone is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%74%70%74%82%88%93%90%86%83%80%78%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hakone

As September rolls into Hakone, Japan, the UV Index maintains a very high level of 10, indicating that sun protection is crucial during outdoor activities. With a burn time of just 15 minutes, it's essential for residents and visitors alike to be aware of their exposure to avoid skin damage. This trend of extreme to very high UV levels peaks in the summer months, consistently prompting earlier burn times, especially in May and July, each reaching an intensity of 11. However, as September progresses into October, a noticeable dip in the UV Index occurs, dropping to 7. To stay informed about the UV levels and protect your skin, check the details at Hakone UV Index.

Maximum UV Index Levels in Hakone for September

The chart shows the monthly maximum UV Index (UVI) for Hakone 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 Hakone typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121110754
Data source: Hakone 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 Hakone

As September unfolds in Hakone, Japan, the region continues to bask in embracing sunshine, boasting 236 hours of sunlight. This vibrant month follows the peak luminosity of August, with an impressive 285 hours, marking the height of summer’s brilliance. The gradual transition into autumn sees a slight dip in sunlight, but September’s hours remain significantly above the winter months, indicating a seasonal shift that still favors outdoor adventures. The overall trend from January's 189 hours to September's generous light showcases a captivating increase, enriching the landscapes with a warm golden hue, ideal for exploring Hakone's breathtaking natural beauty and cultural heritage. As autumn approaches, the balance of light continues to promise picturesque autumn foliage under the continued embrace of the sun.

Monthly Sunshine Duration in Hakone: September Highlighted

The September sunshine duration represents the total number of hours Hakone 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.
JanFebMarAprMayJunJulAugSepOctNovDec189h225h249h260h282h253h229h285h236h201h223h227h
Data source: Hakone September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hakone During September

In Hakone, Japan, the likelihood of sunny weather in September reflects a noticeable trend as summer transitions into autumn. With a 25% chance of sun, September experiences less sunshine compared to the early months of the year, particularly January and February, which boast 57% and 65% respectively. The trend continues through the warmer months, where July and August see only a modest increase in sunny days, hovering around the 26% to 28% range. Following September, October offers a slight rebound to 38%, hinting at more favorable weather conditions as the crispness of autumn sets in. Overall, while September may not be the sunniest month, it serves as a bridge between the summer's heat and the serene beauty of fall, making it a unique time to explore Hakone's natural splendor.

Percentage of Sunny Days in September in Hakone

The chart illustrates the percentage of sunny days in Hakone 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 Hakone experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec57%65%35%42%21%18%26%28%25%38%57%67%
Data source: Hakone September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hakone in September

As September unfolds in Hakone, Japan, the daylight duration begins to subtly shift, offering a gentle transition from the long, sun-drenched summer months. With 12 hours of daylight, September reflects a gradual tapering off from the peak summer light, which reached 14 hours in both June and July. This month stands as a bridge, blending the fading warmth of autumn with the lingering brightness of summer, as daylight gradually diminishes in preparation for October’s 11 hours. Observing these trends, one can appreciate how Hakone’s daylight plays a pivotal role in enriching the region’s captivating landscapes, inviting both residents and visitors to savor the beauty of this transitional period.

Average Daylight Hours in Hakone for September

The chart illustrates the variation in daylight duration in Hakone throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 3m10h 53m11h 58m13h 4m14h14h 28m14h 14m13h 25m12h 22m11h 16m10h 18m9h 49m
Data source: Hakone daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hakone

As September rolls in, Hakone, Japan experiences a gentle breeze with an average wind speed of 1.8 m/s (4 mph), slightly lower than the summer months but consistent with the transitional season. This subtle decline in wind speed from the summer peak provides a serene backdrop for visitors exploring the area's stunning landscapes. Notably, the wind patterns remain stable throughout the fall, maintaining a similar pace into October and November. The overall trend reveals that while summer brings slightly stronger gusts, the autumn air retains a calm, inviting quality, making September an ideal time to embrace the natural beauty of Hakone.

Average September Wind Speed in Hakone

The chart displays monthly wind speed patterns in Hakone, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.92.11.91.92.11.51.41.91.8 m/s1.81.81.9
Data source: Hakone September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Hakone Compares to Other Months

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

September weather is characterized by warm temperatures, with averages around 22°C (72°F) and highs reaching up to 33°C (91°F), creating a summer-like atmosphere. However, it also brings significant rainfall, with 242 mm (9.5 in) of precipitation occurring over 21 days, and humidity levels soaring at 86%. In contrast, January offers a starkly different climate, with much cooler temperatures averaging just 4°C (39°F) and maximums reaching only 17°C (63°F). The precipitation is significantly lower at 69 mm (2.7 in) over just 8 days, accompanied by lower humidity at 76%. For those interested in exploring the specifics of winter conditions, you can find more details here: Hakone weather in January.

September and February showcase vastly different weather patterns. In September, temperatures range from a mild 13°C (56°F) at night to a warm 33°C (91°F) during the day, with an average of 22°C (72°F). This month is characterized by high humidity at 86% and significant rainfall, with 242 mm (9.5 in) of precipitation spread over 21 days. Conversely, February presents a much colder landscape, where temperatures drop to a minimum of -6°C (21°F) and peak at 20°C (67°F), yielding an average of just 5°C (41°F). Precipitation is considerably lower at 83 mm (3.3 in) over 11 days, and humidity drops to 74%. For more details, you can check Hakone weather in February.

September and March exhibit striking contrasts in weather patterns. In September, temperatures range from a mild 13°C (56°F) to a hot 33°C (91°F), with an average of 22°C (72°F), while March is much cooler, with temperatures fluctuating between -6°C (22°F) and 22°C (72°F), and an average of 8°C (47°F). September also experiences higher humidity (86%) and more precipitation (242 mm or 9.5 in) over 21 days, compared to March's lower humidity (70%) and somewhat less rainfall (202 mm or 7.9 in) across 15 days. For more details on March weather, visit Hakone weather in March.

September and April exhibit contrasting weather patterns. September boasts warmer temperatures, with lows around 13°C (56°F) and highs reaching 33°C (91°F), making it the warmer month overall. The average temperature is 22°C (72°F), accompanied by high humidity at 86% and significant rainfall of 242 mm (9.5 in) over 21 days. In contrast, April is much cooler, featuring minimum temperatures of -1°C (31°F) and an average of 12°C (55°F), peaking at 25°C (78°F). Its precipitation is also less, totaling 173 mm (6.8 in) over just 14 days, and humidity is lower at 74%. For more specific details on the weather in Hakone during this month, check out Hakone weather in April.

September and May showcase contrasting weather patterns. September typically experiences warmer temperatures, with a minimum of 13°C (56°F) and an average of 22°C (72°F), peaking at 33°C (91°F). In contrast, May is cooler, with a minimum of 5°C (41°F) and an average of 17°C (63°F), reaching a maximum of 30°C (86°F). Additionally, September sees significantly more rainfall, with 242 mm (9.5 in) across 21 days compared to May's 180 mm (7.1 in) over 14 days. Humidity levels are also higher in September at 86%, versus 81% in May. For more insights into May's weather, you can visit Hakone weather in May.

When comparing the weather in September and June, both months display relatively mild temperatures and considerable humidity. September typically experiences a slightly wider temperature range, with minimums around 13°C (56°F) and maximums reaching up to 33°C (91°F), while June's temperatures range from 12°C (55°F) to a maximum of 30°C (86°F). While September receives a bit more precipitation with 242 mm (9.5 in) over 21 days compared to June's 234 mm (9.2 in) over 18 days, both months are marked by high humidity, at 86% in September and 88% in June. For a closer look at June's weather specifically in Hakone, check out Hakone weather in June.

In comparing the weather of September and July, both months experience warm temperatures, but September tends to be slightly cooler, with an average of 22°C (72°F) compared to July's average of 24°C (76°F). July has higher maximum temperatures, peaking at 34°C (93°F), while September maxes out at 33°C (91°F). Precipitation levels are also notable; July receives more rainfall, totaling 321 mm (12.6 in) over 20 days, whereas September has 242 mm (9.5 in) spread across 21 days. Humidity levels are slightly elevated in July at 93%, compared to September's 86%. For a more detailed look at July’s weather patterns, check out Hakone weather in July.

In comparing the weather of September to August, we see notable differences in temperature and precipitation patterns. September experiences a wider range of temperatures, with a minimum of 13°C (56°F) and a maximum of 33°C (91°F), while August is warmer overall, boasting a minimum of 17°C (63°F) and a maximum of 35°C (95°F). Additionally, September has higher precipitation levels at 242 mm (9.5 in) over 21 days, compared to August’s 198 mm (7.8 in) over 18 days. Humidity remains consistently high in both months, though September sees a slight decrease at 86% compared to August's 90%. For more detailed weather insights, check out Hakone weather in August.

September and October exhibit noticeable changes in weather patterns. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 33°C (91°F), with an average of 22°C (72°F). The month is characterized by high humidity, reaching 86%, and significant precipitation, totaling 242 mm (9.5 in) over 21 days. Conversely, October sees a drop in temperatures, with a minimum of 7°C (45°F), an average of 17°C (62°F), and a maximum of 30°C (87°F). Although the average temperature is cooler, October brings even more rainfall, accumulating 360 mm (14.2 in) across 19 days, alongside a slight decrease in humidity to 83%. For a closer look at what to expect, check out Hakone weather in October.

September and November present quite contrasting weather patterns. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 33°C (91°F), with an average of 22°C (72°F). This month also sees significant rainfall, with 242 mm (9.5 in) spread over 21 days, resulting in a high humidity level of 86%. In stark contrast, November experiences much cooler temperatures, starting at a minimum of 1°C (34°F) and reaching a maximum of 22°C (71°F), with an average of 12°C (53°F). Precipitation drops to 102 mm (4.0 in) over just 13 days, and humidity levels decrease slightly to 80%. For more specific insights into the climate during this month, you can check Hakone weather in November.

September and December showcase significantly contrasting weather patterns. September features a warm climate with average temperatures hovering around 22°C (72°F), peaking at a high of 33°C (91°F). This month is marked by considerable rainfall, with 242 mm (9.5 in) spread over 21 days, resulting in a humidity level of 86%. In stark contrast, December experiences a much cooler climate, with average temperatures dropping to 6°C (44°F) and minimums plummeting to -3°C (27°F). Precipitation decreases substantially to 79 mm (3.1 in) over just 11 days, accompanied by a lower humidity level of 78%. For more information on December's unique weather, you can check Hakone weather in December.

Compare Hakone's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hakone

As September rolls into Hakone, the weather showcases a distinct shift, balancing warm days with cooler nights. The lingering heat, with maximum temperatures peaking at 33°C, contrasts sharply with the more temperate summer months, while the average temperature settles at a comfortable 22°C. However, the increase in precipitation, averaging 242 mm across 21 days, coupled with high humidity levels of 86%, creates a moist atmosphere that can feel quite different from the drier summer climate. This combination of warm days and wet conditions makes September a unique time to experience the lush landscapes of Hakone. For a deeper dive into how this month compares with others throughout the year, explore the full details at Hakone Climate.