September Weather in Biei, Japan

Last updated: August 21, 2025

Experience the captivating weather of Biei, Japan, in September! During this month, temperatures can soar up to a maximum of 28°C (83°F), presenting a delightful warmth, while the average temperature hovers around a comfortable 15°C (60°F). As autumn approaches, the nights can feel brisk with a minimum of 1°C (35°F), offering a refreshing contrast to daytime warmth. However, be prepared for the occasional rain, with a total precipitation of 111 mm (4.4 in) across about 14 days. The air tends to be quite humid, with levels reaching 88%, creating an atmospheric charm that complements the stunning landscapes Biei is known for. Embrace the enchanting transition of seasons and all its wonders this September!

September Temperature in Biei

In September, Biei, Japan transitions from the warmth of summer into the crispness of autumn. The temperatures range from a chilly 1°C (35°F) at night to a pleasant 28°C (83°F) during the day, creating a comfortable average of 15°C (60°F). This month marks a significant drop from the sweltering heights of August, with a gradual cooling of nearly 15°C in the average temperature, signaling the change of seasons. Visitors can expect clear skies and vibrant autumnal foliage, making September a perfect time to explore Biei's stunning landscapes without the summer crowds.

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

The chart illustrates September temperature patterns in Biei, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Biei, 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).
JanFebMarAprMayJunJulAugSepOctNovDec161929405359686760483521
Data source: Temperature data for Biei 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 Biei

In September, Biei, Japan, sees a significant blend of rainfall and weather transitions as summer gives way to autumn. With an average precipitation amount of 111 mm (4.4 in) over 14 days, the month provides a moderate continuation of the wetter August, which recorded a peak of 181 mm. This drop in precipitation highlights a gradual shift, consistent with patterns observed as the seasons change. The rainfall is accompanied by cooler temperatures, setting the stage for the upcoming more stable weather patterns of autumn. Overall, September can be seen as a bridge between the lush, rain-drenched summer and the crisp, dry days of fall in Biei.

September Precipitation Trends in Biei

The chart displays monthly precipitation patterns in Biei, 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 Biei, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec719410284114115123181111154160132
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Biei

September in Biei, Japan, experiences a notable humidity level of 88%, marking a slight decline from the peak of 95% in August. This month represents a transitional phase, as the warmer summer months give way to the cooler autumn, resulting in a gradual drop in moisture. The early autumn air retains a degree of summer’s humidity, but as the region shifts towards October, where humidity levels further decrease to 83%, it indicates a return to the more comfortable ranges experienced in the cooler months. Overall, September bridges the gap between the sweltering summer and the crisp fall, maintaining a pleasant yet humid atmosphere that reflects the changing seasons.

September Average Humidity in Biei

This chart illustrates the average monthly humidity levels in Biei, 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 Biei 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 Biei

In September, Biei experiences a UV Index of 8, categorized as very high, indicating that sun protection is crucial during this month, with a burn time of only 15 minutes. This marks a slight decrease from the peak UV levels seen in the summer months of July and August, where the Index reached its highest at 10. However, month-over-month, the sunny days and potential for outdoor activities remain prominent, emphasizing the need for vigilance against UV exposure. As the season transitions to autumn, the UV levels are still significant, reminding residents and visitors alike to prioritize their skin’s safety. For more information on UV levels throughout the year, check out Biei UV Index.

Maximum UV Index Levels in Biei for September

The chart shows the monthly maximum UV Index (UVI) for Biei 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 Biei typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec23679910108532
Data source: Biei 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 Biei

As September rolls in, Biei, Japan continues to bask in the glow of summer's last rays, boasting an impressive 260 hours of sunshine. This showcases a gradual decrease from the peak sunny days of July, which recorded 304 hours, yet still holds strong compared to the drearier months ahead. Following the vibrant months of May and June, where days were filled with 295 and 285 hours of sunlight respectively, September maintains a warm spark in the landscape, highlighting the beauty of early autumn. As autumn unfolds, residents and visitors cherish these sun-drenched moments while looking forward to the seasonal shifts that are on their way.

Monthly Sunshine Duration in Biei: September Highlighted

The September sunshine duration represents the total number of hours Biei 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.
JanFebMarAprMayJunJulAugSepOctNovDec149h194h247h278h295h285h304h275h260h230h182h183h
Data source: Biei September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Biei During September

In Biei, Japan, September ushers in a pleasant shift in weather as its likelihood of sunny days rises to 37%. This marks a notable increase from the summer months, where July and August see chances of sun at 32% and 29%, respectively. As the season transitions towards autumn, the sunny prospects hint at a brightening landscape, making September an appealing time for visitors to enjoy the stunning natural beauty of the region. Interestingly, this month stands out among others, exceeding the average sunny probabilities seen earlier in the year, with April and May showing lower chances of 35% and 21%, respectively. Overall, September offers a refreshing opportunity to soak up the sun before the chill of October sets in.

Percentage of Sunny Days in September in Biei

The chart illustrates the percentage of sunny days in Biei 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 Biei experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec26%19%33%35%21%40%32%29%37%30%30%27%
Data source: Biei September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Biei in September

As summer gracefully transitions into autumn, September in Biei, Japan, boasts a delightful 12 hours of daylight. This month marks a subtle shift from the longer days of July and August, which peak at 15 hours, inviting a gentle decline in sunlight. The patterns reveal a cyclical rhythm: daylight hours begin to wane after the height of summer, reminding us of the impending chill of winter. Following September, October offers 10 hours of daylight, continuing the trend of shorter days that culminate in the deepest winter months. These variations not only highlight Biei’s changing seasons but also underscore the region's breathtaking landscapes, which are particularly stunning during this enchanting period of transition.

Average Daylight Hours in Biei for September

The chart illustrates the variation in daylight duration in Biei throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 19m10h 28m11h 56m13h 25m14h 42m15h 21m15h 1m13h 54m12h 28m10h 59m9h 40m8h 59m
Data source: Biei daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Biei

As summer transitions into autumn, September in Biei, Japan, ushers in a gentle breeze with an average wind speed of 2.0 m/s (4 mph). This subtle increase from the sluggish winds of July and August signals the onset of change in the vibrant landscape. While the winds are slightly quieter compared to the earlier months of the year, they still offer a refreshing contrast to the warmer summer air. Following the peak in April, where winds reached 2.9 m/s (7 mph), September's breeze continues a gradual resurgence that prepares the picturesque fields of Biei for the stunning colors of fall. As the season progresses into October, a mild uptick in wind speed hints at a lively shift, reminding everyone that nature is in constant motion.

Average September Wind Speed in Biei

The chart displays monthly wind speed patterns in Biei, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.72.72.92.42.01.71.92.0 m/s2.12.52.4
Data source: Biei September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Biei Compares to Other Months

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

September and January present notably contrasting weather conditions. September typically enjoys milder temperatures, ranging from a chilly minimum of 1°C (35°F) to a comfortable average of 15°C (60°F) and a peak of 28°C (83°F). This month also experiences significant precipitation, with 111 mm (4.4 in) spread across 14 days, resulting in a high humidity level of 88%.

In stark contrast, January is marked by frigid temperatures that can plummet as low as -23°C (-10°F), with an average of -9°C (16°F) and a maximum of only 3°C (38°F). Though precipitation is less frequent at 71 mm (2.8 in) over 18 days, the humidity is slightly lower at 84%. For more information, visit Biei weather in January.

September and February present stark contrasts in weather conditions. In September, temperatures range from a mild minimum of 1°C (35°F) to a warm maximum of 28°C (83°F), with an average of 15°C (60°F). The month experiences significant rainfall, totaling 111 mm (4.4 in) over 14 days, accompanied by high humidity at 88%. In contrast, February is much colder, with temperatures dropping to a chilling minimum of -21°C (-5°F) and an average of -7°C (19°F), peaking at just 7°C (45°F). This winter month sees less precipitation at 94 mm (3.7 in), spread over 21 days, and slightly lower humidity at 83%. For more details on February weather, check out Biei weather in February.

September and March present contrasting weather conditions that highlight the transition between summer and winter. In September, temperatures range from a mild 1°C (35°F) at night to a warm maximum of 28°C (83°F) during the day, with an average of 15°C (60°F). This month experiences higher humidity at 88% and considerable precipitation, totaling 111 mm (4.4 inches) over about 14 days. In contrast, March brings much cooler temperatures, with a minimum of -15°C (5°F) and an average of -1°C (30°F), peaking at a maximum of 12°C (54°F). While it sees slightly less precipitation at 102 mm (4.0 inches) spread over 15 days, the humidity is lower at 81%. For more detailed weather information, you can check Biei weather in March.

In comparing the weather between September and April, notable differences emerge. September boasts a wider temperature range, with minimums around 1°C (35°F) and maximums reaching 28°C (83°F), contributing to an average temperature of 15°C (60°F). In contrast, April experiences cooler conditions, starting with a minimum of -9°C (16°F) and peaking at 20°C (69°F), leading to a lower average temperature of 4°C (40°F). While both months see precipitation on about 14 days, September receives more rain, totaling 111 mm (4.4 in), compared to April's 84 mm (3.3 in). Humidity levels are slightly higher in September at 88%, while April maintains a more comfortable 81%. For more information about weather specifics in April, you can visit Biei weather in April.

September and May present distinct weather patterns, each with its unique characteristics. In September, temperatures range from a minimum of 1°C (35°F) to a maximum of 28°C (83°F), with an average of 15°C (60°F). The month experiences significant rainfall, totaling 111 mm (4.4 in) over approximately 14 days and a high humidity level of 88%. In contrast, May features slightly warmer conditions, with temperatures spanning from 0°C (32°F) to 31°C (88°F) and an average of 11°C (53°F). Precipitation in May is slightly higher at 114 mm (4.5 in) over 15 days, with humidity at a marginally lower 86%. For a deeper dive into the specifics of May weather, you can check Biei weather in May.

In comparing the weather of September and June, both months exhibit similar average temperatures, around 15°C (59°F), but with slightly different extremes; September can reach a maximum of 28°C (83°F), while June peaks at 27°C (80°F). Precipitation levels are also comparable, with September receiving 111 mm (4.4 in) and June slightly more at 115 mm (4.5 in), both spread over approximately 14 days. Humidity remains high in both months, with September at 88% and June a notch lower at 87%. For more detailed information about June weather, you can check Biei weather in June.

When comparing the weather between September and July, several key differences emerge. September experiences a wider temperature range, with minimums dropping to 1°C (35°F) and maximums reaching up to 28°C (83°F), averaging around 15°C (60°F). In contrast, July remains warmer, with minimum temperatures at 9°C (48°F) and maximums peaking at 30°C (86°F), resulting in a comfortable average of 20°C (68°F). Precipitation levels are similar, with September receiving 111 mm (4.4 in) over 14 days and July slightly higher at 123 mm (4.8 in) over 13 days. Additionally, July's humidity is slightly higher at 93% compared to September's 88%. For more details on July weather in Biei, you can check this link: Biei weather in July.

In comparing the weather between September and August, September tends to be cooler with an average temperature of 15°C (60°F), while August is warmer with an average of 19°C (67°F). September experiences a maximum temperature of 28°C (83°F), compared to August's peak of 31°C (88°F). Precipitation is also lower in September, with 111 mm (4.4 in) over 14 days, compared to 181 mm (7.1 in) over 16 days in August. Additionally, humidity levels are somewhat lower in September at 88%, contrasting with August’s higher humidity of 95%. For more details on August weather, you can refer to Biei weather in August.

September and October showcase a notable shift in weather conditions. September tends to be warmer, with temperatures ranging from a minimum of 1°C (35°F) to a maximum of 28°C (83°F), averaging around 15°C (60°F). This month also experiences significant rainfall, totaling 111 mm (4.4 in) over 14 days, coupled with high humidity at 88%. In contrast, October experiences cooler temperatures, with a minimum of -4°C (25°F) and averaging 9°C (48°F), while the maximum reaches 23°C (73°F). The month sees an increase in precipitation to 154 mm (6.0 in) over 16 days, although the humidity drops slightly to 83%. For more detailed insights, you can visit Biei weather in October.

In September, temperatures range from a mild 1°C (35°F) at night to a warm 28°C (83°F) during the day, with an average of 15°C (60°F). This month also sees significant rainfall, totaling 111 mm (4.4 in) across approximately 14 days, and the humidity is relatively high at 88%. In stark contrast, November brings much colder temperatures, with lows plummeting to -14°C (7°F) and an average of only 2°C (35°F). The maximum temperature reaches a cooler 15°C (59°F). Precipitation increases to 160 mm (6.3 in) over about 23 days, while humidity drops slightly to 79%. For more specific details on November weather, you can check Biei weather in November.

September and December present starkly contrasting weather conditions. In September, temperatures range from a mild 1°C (35°F) at night to a warm 28°C (83°F) during the day, with an average of 15°C (60°F). The month experiences considerable precipitation, averaging 111 mm (4.4 in) over 14 days and high humidity at 88%. In contrast, December brings a chilling plunge in temperatures, with lows reaching -22°C (-7°F) and an average of -6°C (21°F). Though slightly wetter, with 132 mm (5.2 in) over 27 days, December's humidity is lower at 80%. This significant drop in temperature and the increase in precipitation days create a decidedly colder and more inhospitable environment. For more details, check out Biei weather in December.

Compare Biei's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Biei

As September rolls in, Biei welcomes a transition from the warmth of summer to the crispness of autumn. With an average temperature that steadily cools down, days are marked by a pleasant yet refreshing chill, particularly in the early mornings and evenings. Unlike the drier months that precede it, September experiences significant rainfall, creating a lush landscape framed by vibrant fall colors. The high humidity adds a touch of moisture to the air, enveloping the town in a soft, serene atmosphere. This unique blend of warmth and wetness sets September apart, making it a captivating time to explore the natural beauty of Biei. For more detailed insights into the weather trends, visit Biei Climate.