Last updated: August 21, 2025
September in Yamaguchi, Japan brings a blend of warm temperatures and substantial rainfall, making it a vibrant month for the region. With maximum highs reaching 35°C (95°F) and an average temperature of 24°C (75°F), the days are typically balmy, inviting outdoor explorations. However, the comfort can be punctuated by cooler nights averaging 13°C (56°F). This month also sees about 240 mm (9.4 in) of precipitation over approximately 14 rainy days, contributing to the lush greenery characteristic of the area. The humidity levels hover at a high 84%, adding to the tropical feel of the season. Enjoy the dynamic weather that September brings, whether soaking in the sun or appreciating the refreshing showers!
In September, Yamaguchi experiences a noticeable transition from the sweltering summer heat to the more temperate autumn climate. With minimum temperatures averaging around 13°C (56°F) and reaching maximums of 35°C (95°F), this month still holds onto the warmth but begins to shed the intensity of August. The average temperature of 24°C (75°F) indicates a shift, as days remain pleasantly warm, yet the cool evenings hint at the approaching fall. This blend of lingering summer warmth and refreshing autumn breezes makes September an ideal time to enjoy the natural beauty of the region as leaves start to turn and the humidity begins to dissipate.
In September, Yamaguchi experiences significant rainfall, with 240 mm (9.4 in) of precipitation over an average of 14 days. This marks a notable shift from the intense downpours of July and August, which recorded 340 mm and 265 mm, respectively. Although September’s total is reduced compared to the summer months, it remains indicative of the lingering influence of the monsoon season. As the region transitions into autumn, the precipitation patterns demonstrate a gradual decline, foreshadowing the drier months ahead in October and November. The consistent rainfall not only nourishes the lush landscapes of Yamaguchi but also reflects the rich climatic tapestry characterizing this part of Japan during the late summer and early fall.
In Yamaguchi, Japan, the September humidity levels sit comfortably at 84%, marking a slight decrease from the stifling peaks of July and August, which boast humidity levels of 95% and 93%, respectively. This month signifies a transition from the intense summer moisture as it begins to edge toward the dryer autumn months. Interestingly, overall humidity tends to fluctuate throughout the year, with the highest levels occurring in the summer months, while values gradually decline as the seasons shift. September's 84% contrasts sharply with the more humid months earlier in the summer, suggesting a refreshing, albeit still muggy, ease into fall.
In September, Yamaguchi experiences a significant shift in UV exposure compared to the blazing summer months, with a UV Index of 10, categorizing it as very high. This marks a slight decrease from the peak of 12 seen in July and August, yet the burn time remains critical at only 15 minutes for unprotected skin. As the summer fades, it’s essential to remain vigilant about sun safety; even as temperatures cool, prolonged exposure can still lead to skin damage. With the glow of autumn approaching, understanding the UV trends like these is crucial for health and well-being. For more detailed insights, check out Yamaguchi UV Index.
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As the warm embrace of September unfolds in Yamaguchi, the sun shines brightly for 257 hours, marking a gentle transition from the sun-drenched summer months of July and August, which boast impressive totals of 280 and 303 hours respectively. This gradual decline in daylight reflects the shifting seasons, yet September still holds its own, outshining the earlier months of the year like January and February, which struggled with only 174 and 229 hours of sunshine. The steady increase from January to August showcases the region's increasing exposure to sunlight, peaking in the height of summer, while September maintains a robust presence before ushering the cooler days of October. Overall, Yamaguchi in September offers a harmonious balance of warmth and light, inviting residents and visitors alike to bask in the fading summer glow.
As September rolls into Yamaguchi, Japan, the chances of sunny weather dip slightly to 30%, marking a transitional phase where summer’s warmth begins to fade. This month typically experiences one of the lower probabilities for sunshine, trailing behind the sunnier months of April and October, where the likelihood climbs to 47% and 58%, respectively. Interestingly, September's sun chances are a modest improvement from the dismal summer months of July and August, which see the lowest figures at 22% and 25%. Overall, while September may not boast the sunniest days, it offers a gentle shift towards clearer skies, hinting at the beauty that autumn will soon unveil.
In Yamaguchi, Japan, September marks a transition as daylight begins to wane, offering about 12 hours of sunlit hours— a slight dip from the 14 hours enjoyed during the peak of summer in July and June. This gradual decrease aligns with the region's progression towards autumn, following a vibrant summer filled with extended daylight. The trend of increasing sunlight from 10 hours in January to a maximum of 14 hours in midsummer peaks before a gentle decline toward the winter months. As September rolls in, the city embraces the softer, golden hues of an early fall, making it a perfect time for outdoor activities amidst temperate conditions and diminishing daylight.
As summer fades into autumn, September's wind in Yamaguchi offers a gentle transition, with an average speed of 2.6 m/s (6 mph). This slight dip from the previous months mirrors the overall trend of diminishing winds as the year progresses, peaking earlier during the colder winter months, notably 3.3 m/s in December. After the sweltering heat of July and August, where the winds barely reach above 2.7 m/s, September maintains a calm yet refreshing breeze, preparing the region for the shifting seasons ahead. This gradual reduction in wind speed not only marks the approach of fall but also invites a serene atmosphere, ideal for enjoying the lingering warmth of late summer.
Weather in Yamaguchi varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Yamaguchi, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present vastly different weather profiles. September boasts a warm average temperature of 24°C (75°F) with maximums reaching up to 35°C (95°F), making it a pleasant time for outdoor activities despite the high humidity of 84%. However, it also sees significant rainfall, with 240 mm (9.4 in) over about 14 days. In contrast, January is characterized by much cooler temperatures, with an average of just 5°C (42°F) and minimums dipping down to -4°C (25°F). It is also drier, receiving only 58 mm (2.3 in) of precipitation across 9 days, and lower humidity at 76%. For a closer look at what to expect in January, check out Yamaguchi weather in January.
September and February present striking contrasts in weather. In September, temperatures range from a mild 13°C (56°F) at night to a sweltering 35°C (95°F) during the day, accompanied by high humidity at 84%. This month also sees significant rainfall, totaling 240 mm (9.4 in) over 14 days. In contrast, February experiences much cooler conditions, with temperatures dropping as low as -3°C (27°F) and averaging around 6°C (43°F). Precipitation is considerably less, at 78 mm (3.1 in) over just 9 days, and the humidity is lower at 72%. For a deeper dive into February’s weather specifics, check out Yamaguchi weather in February.
September and March exhibit striking contrasts in weather conditions. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 35°C (95°F), with an average of 24°C (75°F). The month also witnesses substantial rainfall, totaling 240 mm (9.4 in) over 14 days, accompanied by high humidity levels at 84%. In contrast, March experiences much cooler temperatures, with a minimum of -1°C (31°F) and a maximum of 22°C (72°F), and an average of only 10°C (51°F). Precipitation is lower, at 130 mm (5.1 in) over 12 days, and humidity drops to 69%. For more detailed information, check Yamaguchi weather in March.
In September, the weather is significantly warmer, with average temperatures reaching 24°C (75°F) and maximums peaking at 35°C (95°F), compared to April, where the average temperature is only 14°C (58°F) and the maximum reaches 26°C (79°F). Additionally, September experiences more precipitation, totaling 240 mm (9.4 in) over 14 days, while April sees less rainfall at 122 mm (4.8 in) across 10 days. Humidity levels are also higher in September at 84%, compared to 75% in April, contributing to a more sultry atmosphere during the early fall months. For a detailed overview of the weather patterns in April, you can check Yamaguchi weather in April.
When comparing the weather between September and May, we notice significant differences in temperature and precipitation patterns. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 35°C (95°F), with an average of 24°C (75°F). This month also sees higher precipitation levels at 240 mm (9.4 in) over about 14 days, maintaining a consistent humidity of 84%. In contrast, May experiences milder temperatures, with a minimum of 5°C (42°F) and a maximum of 30°C (87°F), averaging around 19°C (67°F). Precipitation is lower at 136 mm (5.4 in) over 11 days, while humidity remains steady at 84%. For more details on the weather in May, visit Yamaguchi weather in May.
In comparing September and June weather, September tends to offer warmer temperatures with an average of 24°C (75°F), peaking at a maximum of 35°C (95°F), compared to June's cooler average of 22°C (73°F) and maximum of 31°C (89°F). Additionally, September experiences higher precipitation levels, totaling 240 mm (9.4 in) over 14 days, while June sees slightly less with 198 mm (7.8 in) over 13 days. Humidity is also slightly lower in September at 84% compared to June's 88%. For a detailed look at the weather in June, you can visit Yamaguchi weather in June.
In September, the weather typically sees a more moderate temperature range, with minimums around 13°C (56°F) and maximums reaching up to 35°C (95°F), resulting in an average temperature of 24°C (75°F). In contrast, July experiences hotter conditions, with minimum temperatures of 17°C (63°F) and highs peaking at 37°C (99°F), averaging 26°C (80°F). Despite being warmer, July also records higher precipitation levels at 340 mm (13.4 in) over 20 days, compared to September's 240 mm (9.4 in) spread across 14 days. The humidity is notably higher in July at 95%, whereas September has a slightly lower humidity level of 84%. For a more detailed look, check out Yamaguchi weather in July.
In comparing the weather of September and August, September typically experiences slightly cooler temperatures, with a minimum of 13°C (56°F) and an average of 24°C (75°F), whereas August has higher temperatures, starting at a minimum of 19°C (66°F) and averaging 28°C (83°F). August also sees more extreme heat, reaching a maximum of 38°C (100°F), compared to September's maximum of 35°C (95°F). Additionally, both months have notable rainfall, but September records 240 mm (9.4 in) over 14 days, while August has a bit more precipitation at 265 mm (10.4 in) across 15 days. The humidity levels are also pronounced in both months, with August peaking at 93% compared to September's 84%. More details can be found in Yamaguchi weather in August.
September and October showcase a notable shift in weather patterns. September experiences warmer temperatures, with minimums around 13°C (56°F) and maximums peaking at 35°C (95°F), while October cools down, featuring a minimum of 8°C (46°F) and a maximum of 30°C (87°F). Additionally, September is characterized by higher humidity at 84% and significant precipitation of 240 mm (9.4 inches) over 14 days, compared to October's milder 79% humidity and reduced rainfall of 120 mm (4.7 inches) across 10 days. The transition from September's heat to October's cooler and drier climate marks the beginning of autumn's embrace. For more detailed insights, check out Yamaguchi weather in October.
September and November present a striking contrast in weather conditions. September enjoys warmer temperatures, with an average of 24°C (75°F) and highs reaching up to 35°C (95°F), while November experiences a cooler climate, with an average temperature of 13°C (55°F) and maximums of 25°C (78°F). Additionally, September is characterized by higher humidity levels at 84% and significant rainfall, receiving 240 mm (9.4 in) over 14 days, whereas November sees a much drier pattern with only 41 mm (1.6 in) of precipitation spread over just 5 days and a drop in humidity to 76%. For more detailed information, you can check out Yamaguchi weather in November.
September weather is characterized by warmth and high humidity, with temperatures ranging from a low of 13°C (56°F) to a maximum of 35°C (95°F). During this month, there is significant rainfall, averaging 240 mm (9.4 in) over approximately 14 days, contributing to a humid environment with an average humidity of 84%. In contrast, December brings cooler temperatures, with lows dropping to -1°C (31°F) and an average temperature of 7°C (46°F), peaking at 21°C (70°F). Precipitation is also reduced, totaling 67 mm (2.6 in) over just 8 days, and humidity decreases to 75%. For more specific details on December weather, you can visit Yamaguchi weather in December.
As September unfolds in Yamaguchi, the weather transitions noticeably from the sweltering summer months to a more comfortable climate. With average temperatures settling around 24°C (75°F), the oppressive heat begins to ease, although the maximum can still reach up to 35°C (95°F) on warmer days. Humidity remains high at 84%, contributing to a muggy atmosphere, especially during the rainy days, which total around 14 in this month alone, bringing a significant 240 mm (9.4 in) of precipitation. This noticeable shift not only marks the end of summer but also heralds the onset of autumn, making it a unique and transitional month in Yamaguchi. For a deeper insight into what to expect throughout the year, explore the detailed Yamaguchi Climate.