Last updated: August 21, 2025
September in Hayama, Japan offers a delightful blend of warm temperatures and refreshing sea breezes. With a maximum temperature reaching 29°C (84°F) and an average of 24°C (75°F), visitors can enjoy pleasant outdoor activities. However, it’s essential to prepare for frequent rain, as the month sees about 208 mm (8.2 in) of precipitation spread over 17 days. Humidity levels hover around a notable 86%, creating a lush, vibrant atmosphere. Embrace the charm of late summer while being mindful of the occasional drizzle that enriches the region's natural beauty.
In September, Hayama, Japan experiences a delightful transition from the sweltering summer months to a more temperate fall. With minimum temperatures around 18°C (65°F) and average highs reaching 29°C (84°F), the weather remains pleasantly warm, making it ideal for outdoor activities. This slight dip from the peak summer heat hints at the impending change of seasons, as average temperatures settle around 24°C (75°F), offering a comfortable respite. Summer's lingering warmth creates a vibrant atmosphere, perfect for enjoying the beautiful coastal scenery and local festivals, while the gradual cooling foreshadows the refreshing autumn that follows.
September in Hayama, Japan, marks a significant increase in precipitation, boasting an impressive 208 mm (8.2 in), making it one of the wettest months of the year. Accompanying the rainfall, the number of precipitation days also peaks at 17, reflecting the transition into autumn when moisture-laden air often leads to sustained showers. This robust precipitation follows the relatively drier summer months and paves the way for October, which continues the trend with even higher totals. The shift indicates a clear pattern: as the island moves from the warmth of summer into the cooler embrace of fall, the rain intensifies, enriching the landscape with vibrant hues.
In September, Hayama experiences a notable shift in humidity, with levels reaching 86%. This marks a slight decrease from the peak months of July and August, where the humidity soared to 93% and 90%, respectively. As summer gives way to autumn, the air begins to feel a touch less oppressive, although it still retains a significant moisture content. Compared to the earlier months of the year, such as January and February—when humidity hovered around 76% and 74%—September presents a transitional period, showcasing the lingering warmth while hinting at the drier conditions that will characterize October and beyond. The overall trend indicates a gradual ebb of humidity as the seasons change, providing a refreshing respite after the hot, humid summer months.
September in Hayama, Japan, sees a very high UV Index of 10, indicating that sun exposure can be risky if proper precautions aren’t taken. As summer wanes, the UV intensity slightly decreases from the extreme levels recorded in July and August, where the Index peaked at 11, allowing for a bit more time in the sun—approximately 15 minutes before one risks burning. This transition marks a significant trend, as the UV Index begins to decline from its peak summer levels, shifting back towards the more moderate indices seen in spring and autumn. However, it remains crucial to stay protected during this month. For more detailed information on UV ratings throughout the year, check out Hayama UV Index.
UV Risk Categories
As September unfolds in Hayama, Japan, the sun graces the region with an impressive 239 hours of radiant light, providing a gentle transition from the long, sun-blushed days of summer. While August boasts the peak with 297 hours of sunshine, September still stands out with a healthy amount of sunshine, ensuring that outdoor adventures and seascapes remain vibrant. Following the lush month of May, which shines brightly with 286 hours, the late summer sun continues to dwindle but retains its warmth, encouraging locals and visitors alike to savor the last warm days of the year. As the days start to cool and October approaches with a quieter 205 hours, September's balance of light offers a delightful farewell to summer, inviting all to bask in the lingering warmth before the golden hues of autumn fully embrace Hayama.
As the summer fades, September in Hayama, Japan, brings a 29% chance of sunny weather, reflecting a notable dip in sunshine compared to the preceding months. This decrease in clear skies contrasts sharply with the sunnier days seen earlier in the year, particularly in February, which boasts a 64% chance of sun. While September marks the transition into autumn, the likelihood of overcast days tends to increase, setting the stage for the more sunshine-friendly months of October and November, which climb back up to 48% and 62%, respectively. Overall, if you're planning to soak up the sun in September, be prepared for the possibility of cloud cover as this month solidifies the shift towards the cooler, rustling leaves of fall.
In Hayama, Japan, the rhythm of daylight unfolds beautifully throughout the year, with September marking a delicate transition. As summer fades, the daylight duration decreases to 12 hours, providing a gentle segue into autumn. This follows the peak months of May through July, where the sun bathes the area in an impressive 14 hours of light. Interestingly, while September offers fewer hours than the summer months, it still holds more than the winter months, reflecting a gradual shift rather than a stark drop. As the days shorten, the landscape embraces the warm hues of early autumn, making September a picturesque time to enjoy Hayama’s natural beauty.
As September ushers in a gentle transition from summer to autumn in Hayama, Japan, the average wind speed reaches 5.2 m/s (12 mph), mirroring the consistent breezes of the preceding months. This moderate wind velocity follows a dip during the sultry summer, where July recorded a mere 3.3 m/s (7 mph), painting a vivid picture of the calm, humid days. Notably, September's winds pick up slightly before gradually increasing again into the autumn months, suggesting a harmonious balance between the warmth of summer’s end and the crispness of fall’s arrival. As the landscape subtly transforms, these winds carry hints of change, flowing through the coastal beauty of Hayama.
Weather in Hayama varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Hayama, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present markedly different weather conditions. In September, temperatures range from a minimum of 18°C (65°F) to a maximum of 29°C (84°F), with an average of 24°C (75°F). The month experiences significant rainfall, totaling 208 mm (8.2 in) over 17 days and high humidity at 86%. In contrast, January sees much cooler temperatures, with a minimum of 1°C (34°F), an average of 8°C (47°F), and a maximum of 18°C (64°F). Precipitation drops to 64 mm (2.5 in) over just 6 days, accompanied by lower humidity at 76%. For more detailed information, check out Hayama weather in January.
September and February present stark contrasts in weather patterns. In September, temperatures are noticeably warmer, with minimums around 18°C (65°F) and averages peaking at 24°C (75°F), while maximums can reach up to 29°C (84°F). This warmth is accompanied by high humidity levels at 86% and substantial rainfall, with 208 mm (8.2 in) over 17 days. In contrast, February experiences much cooler temperatures, averaging a modest 8°C (47°F) and peaking at just 17°C (63°F). Precipitation drops significantly to 62 mm (2.4 in) over only 8 days, and humidity levels also decrease to 74%. For more details on February weather, check Hayama weather in February.
September and March showcase contrasting weather patterns. In September, temperatures are notably warmer, with minimums around 18°C (65°F) and average highs reaching 29°C (84°F), creating a pleasant yet humid atmosphere with an average humidity of 86%. However, this month also experiences significant rainfall, totaling 208 mm (8.2 inches) over 17 days. In contrast, March presents a much cooler climate, with minimum temperatures dropping to 3°C (38°F) and average highs of 19°C (66°F). The humidity is considerably lower at 70%, and precipitation is also less frequent, totaling 172 mm (6.8 inches) over 12 days. For more detailed insights about March weather, you can check Hayama weather in March.
When comparing the weather of September and April, notable differences emerge in temperature and precipitation. September features a warmer climate, with minimum temperatures around 18°C (65°F) and an average of 24°C (75°F), peaking at 29°C (84°F). In contrast, April starts cooler, with minimum temperatures at 6°C (43°F) and an average of 14°C (58°F), reaching a maximum of 21°C (70°F). Precipitation levels also vary; September sees a higher rainfall of 208 mm (8.2 in) over 17 days, compared to April's 141 mm (5.5 in) over 12 days. Additionally, September has a higher humidity level of 86%, while April’s humidity is at 74%. For more detailed information on April weather, you can visit Hayama weather in April.
In comparing the weather of September and May, September tends to be warmer and more humid. With minimum temperatures averaging around 18°C (65°F) and peaking at 29°C (84°F), September presents a warm and often muggy atmosphere, accompanied by significant precipitation of 208 mm (8.2 in) over 17 days. In contrast, May experiences cooler temperatures, with a minimum of 12°C (54°F) and a maximum of only 23°C (74°F), alongside less rainfall at 148 mm (5.8 in) over 11 days. Additionally, May has a lower humidity level at 81%. For more insights on May's weather, you can check out Hayama weather in May.
In comparing the weather of September and June, September tends to be warmer overall, with average temperatures reaching 24°C (75°F) compared to June's average of 21°C (70°F). The maximum temperatures in September can soar up to 29°C (84°F), while June's maximum is slightly cooler at 26°C (79°F). However, September also experiences more precipitation, with 208 mm (8.2 in) spread over 17 days, in contrast to June's 197 mm (7.8 in) over 13 days. Both months have high humidity levels, with September at 86% and June slightly higher at 88%. For a closer look at June weather patterns, you can visit Hayama weather in June.
When comparing the weather in September and July, we see some notable differences. September experiences slightly cooler temperatures, with a minimum of 18°C (65°F) and an average of 24°C (75°F), while July has a minimum of 19°C (66°F) and an average of 25°C (77°F). Interestingly, July has a max temperature of 28°C (83°F) compared to September's peak of 29°C (84°F). Precipitation levels are also quite similar, with July receiving 226 mm (8.9 in) and September seeing a slightly lower total of 208 mm (8.2 in), both across 17 days. However, humidity is higher in July at 93%, compared to September's 86%. For a detailed look at July weather, you can refer to Hayama weather in July.
In September, the weather tends to be slightly cooler compared to August, with average temperatures ranging from a minimum of 18°C (65°F) to a maximum of 29°C (84°F), while August enjoys warmer temperatures with a minimum of 21°C (70°F) and a maximum of 31°C (87°F). Precipitation is significantly higher in September, totaling 208 mm (8.2 in) over 17 days, compared to the 129 mm (5.1 in) spread across 12 days in August. Additionally, September experiences a lower humidity level of 86%, while August is slightly more humid at 90%. For more details, you can check Hayama weather in August.
September typically boasts warmer temperatures, with minimums around 18°C (65°F) and average highs peaking at 29°C (84°F). In contrast, October sees a drop in temperatures, with minimums around 13°C (56°F) and a maximum of 26°C (79°F), making it noticeably cooler. Additionally, October tends to be wetter, receiving approximately 303 mm (11.9 in) of precipitation compared to September's 208 mm (8.2 in), despite both months experiencing rain on about 17 days. Humidity is slightly lower in October at 83%, compared to September's 86%. For more details, you can check Hayama weather in October.
In September, the weather is warm and humid, with average temperatures ranging from a minimum of 18°C (65°F) to a maximum of 29°C (84°F). The month experiences considerable precipitation, totaling 208 mm (8.2 in) over 17 days, coupled with high humidity levels at 86%. In contrast, November brings a notable drop in temperatures, with averages moving from a minimum of 6°C (43°F) to a maximum of 21°C (71°F) and an overall average of 15°C (60°F). The month is drier, receiving only 111 mm (4.4 in) of rainfall over 12 days and with slightly lower humidity at 80%. This transition marks a shift from the warm, sultry days of September to the cooler and more comfortable climate of November, making it an intriguing time to experience the changing seasons. For more specific details about November weather, you can visit Hayama weather in November.
September weather is characterized by warm temperatures, with averages around 24°C (75°F) and highs reaching up to 29°C (84°F). This month experiences significant rainfall, totaling 208 mm (8.2 in) over 17 days, combined with high humidity levels of 86%. In contrast, December brings much cooler conditions, with average temperatures falling to 11°C (52°F) and maximums of 21°C (69°F). Precipitation drops to 82 mm (3.2 in) across 11 days, and the humidity decreases to 78%. For more details on December weather, you can check Hayama weather in December.
As September transitions summer into autumn in Hayama, the weather showcases a unique blend of warmth and moisture. With an average temperature that comfortably hovers around 24°C (75°F), it feels notably warmer than the upcoming months, yet the humidity level remains high at 86%, making it feel quite a bit sultry. Frequent rainy days—numbering up to 17—contribute to the 208 mm (8.2 in) of precipitation, disrupting the otherwise mild climate. While temperatures begin to dip later in the year, September retains an air of lingering warmth, inviting both locals and visitors to enjoy the beauty of Hayama before the cooler days take hold. For a deeper dive into what makes Hayama’s climate truly special, check out Hayama Climate.