Last updated: August 21, 2025
In September, China and Japan experience a transition marked by warm temperatures and high humidity, with maximums reaching 30°C (86°F) and an average of 28°C (82°F). The month sees a notable minimum temperature of 24°C (75°F), creating a warm backdrop for daily activities. However, this warmth is accompanied by substantial precipitation, totaling 210 mm (8.3 in) over about 20 days—making it one of the wetter months. With an average humidity level of 82%, the weather feels particularly muggy, prompting residents and visitors alike to stay prepared for both heat and the frequent showers.
As September rolls in, both China and Japan experience warm temperatures that mark the transition between summer and autumn. With a minimum of 24°C (75°F) and an average hovering around 28°C (82°F), the weather remains pleasantly warm, perfectly suited for outdoor activities. The maximum temperature peaks around 30°C (86°F), showcasing the lingering warmth of summer. This trend of diminishing temperatures from the height of summer is notable; the gradual decline sets the stage for cooler months ahead, making September a delightful time for both locals and travelers to enjoy the vibrant landscapes before the cooler autumn breezes take over.
September marks a notable peak in precipitation for both China and Japan, with 210 mm (8.3 in) of rainfall recorded over 20 rainy days. This month stands out as a transitional period, bridging the humid summer months and the drier autumn to come. The rainfall in September is slightly higher than August's 152 mm (6.0 in), demonstrating an upward trend as the seasons shift. This increase in precipitation, coupled with a sustained number of rainy days, underscores the lingering effects of summer storms while also heralding the approach of autumnal weather patterns. As the landscape becomes lush with greenery from the abundant rain, September serves as a reminder of nature's dynamic rhythms and the changing climate in the region.
As September rolls in, humidity levels in China and Japan remain notable, settling at 82%. This figure reflects a slight dip from the peak summer months of June and July, both of which saw a high of 86%. The gradual decrease points to the transition into autumn, following a warm and humid summer. Interestingly, this September level is on par with August, suggesting a mild consistency before the next slight reduction to 80% in October. Overall, the trend indicates a shift from the high humidity of summer, creating a more comfortable atmosphere as the seasons change.
In September, the UV Index in China and Japan reaches a peak of 13, placing it firmly in the extreme exposure category. This trend continues from the preceding months, where the UV Index has remained constant at 13, indicating a critical need for sun protection, with a burn time of only 10 minutes. Remarkably, this high level of UV exposure is characteristic of the summer season, reflecting a consistent pattern from June through September. As temperatures start to dip in October, we see a decrease to a UV Index of 9, transitioning to a very high exposure category and extending the burn time to 15 minutes. For detailed insights on UV conditions, check the China UV Index.
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As September arrives in China and Japan, it marks a transition where the summer sun begins to wane but still casts a generous glow, providing 292 hours of sunshine—just a notch below the peak summer months of July and August with 315 and 318 hours, respectively. Following the vibrant energy of summer, the sun gradually begins to retreat, but not before September offers a delightful blend of warmth and early autumn hues. This month can be seen as a bridge, maintaining a healthy amount of sunlight while paving the way for the cooler months ahead, as evidenced by the drop that follows into October’s 272 hours. Overall, the sunshine hours in this part of the world follow a clear trend—markedly climbing from the depths of winter until the height of summer, before gently receding into the crisp embrace of fall.
As September rolls in, there's a notable surge in the likelihood of sunny weather across China and Japan, with a promising 58% chance of sunshine. This marks a significant increase compared to the preceding months, where summer ended with only moderate sunshine, particularly in June and July, which dipped to 11%. The transition into autumn reveals a trend of brighter days, as September emerges as one of the sunniest months of the year. Following this peak, the chance of sunlight begins to taper off in October, suggesting that September is an ideal time for outdoor activities and enjoying the last warm days before the chill of winter sets in.
As September rolls in, daylight hours in China and Japan witness a notable transition, offering about 12 hours of sunlight. This slight reduction follows the peak summer months of June through August, where daylight extended up to 13 hours. The warm, vibrant days of late summer gradually yield to a gentle decline in daylight as autumn approaches. Interestingly, September marks a pivotal point, reflecting the shift towards shorter days, with daylight hours steadily diminishing into October. This trend not only signals the changing seasons but also enhances the cultural richness of both countries, where the beauty of autumn foliage becomes increasingly celebrated as the sunlight wanes.
As summer gracefully transitions into autumn, September wind in both China and Japan reveals a notable decline in average wind speeds, dipping to a gentle 5.6 m/s (12 mph). This shift contrasts sharply with the typically breezier months earlier in the year, where winds often reach over 7 m/s (15 mph). The gradual decrease in wind speed marks the seasonal change, with September often characterized by calmer days as both regions prepare for the cooler months ahead. In the broader context, the wind patterns suggest a rhythmic ebb and flow, with the anticipation of revitalized breezes returning in October, when speeds bounce back to 7.8 m/s (18 mph), invigorating the landscape once more.
Weather in China varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in China, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January showcase a significant contrast in weather patterns. September is characterized by warm temperatures, with minimums around 24°C (75°F) and averages reaching 28°C (82°F), combined with high humidity levels of 82%. The month is also marked by considerable rainfall, receiving 210 mm (8.3 in) over approximately 20 days. In stark contrast, January experiences much cooler conditions, with temperatures dipping to a minimum of 12°C (53°F) and an average of 18°C (64°F), peaking at 23°C (74°F). Additionally, January has far less precipitation, totaling 105 mm (4.1 in) over just 10 days, and a decrease in humidity to 71%. This variation highlights the transition from the warm, humid end of summer to the cooler, drier onset of winter. For more detailed information, you can check China weather in January.
September features warm temperatures, with averages around 28°C (82°F) and highs reaching up to 30°C (86°F), while February brings a cooler climate, with average temperatures of 18°C (64°F) and a maximum of 24°C (75°F). The humidity in September is notably higher at 82%, contributing to a more tropical feel, as compared to February's more moderate 71%. Additionally, September experiences significant rainfall, averaging 210 mm (8.3 in) over 20 days, whereas February sees less precipitation, totaling 113 mm (4.5 in) across 13 days. For more detailed insights, visit China weather in February.
September and March present distinct contrasts in weather. September boasts a warmer climate, with average temperatures ranging from a minimum of 24°C (75°F) to a maximum of 30°C (86°F), while March is cooler, averaging between 14°C (57°F) and 24°C (75°F). Additionally, September experiences higher precipitation levels, totaling 210 mm (8.3 in) over about 20 days, in comparison to March’s 138 mm (5.5 in) across 13 days. Humidity levels also differ slightly, with September at 82% and March at 76%. For more detailed insights on weather conditions during this time, refer to China weather in March.
When comparing the weather in September and April, we see distinct differences in temperature and precipitation. September boasts warmer temperatures with a minimum of 24°C (75°F), an average of 28°C (82°F), and a maximum reaching 30°C (86°F). In contrast, April is cooler, with a minimum of 15°C (59°F), an average of 21°C (70°F), and a maximum of 25°C (78°F). Precipitation levels are notably higher in September, with 210 mm (8.3 inches) spread over 20 days, compared to April's 119 mm (4.7 inches) over just 12 days. Both months share the same humidity level of 82%, giving a consistently humid feel to the environment. For more details on April weather, check out China weather in April.
In September, the weather is generally warmer, with minimum temperatures around 24°C (75°F) and an average of 28°C (82°F), peaking at 30°C (86°F). This month experiences significant rainfall, accumulating 210 mm (8.3 in) over 20 days, paired with high humidity at 82%. In contrast, May offers milder conditions, with minimum temperatures of 19°C (66°F) and an average of 23°C (74°F), reaching a maximum of 27°C (80°F). Precipitation in May is slightly less, totaling 206 mm (8.1 in) across 13 days, and humidity is also higher at 84%. Both months showcase substantial rainfall, but September is notably warmer and wetter. For more details on May's weather in China, check out China weather in May.
In comparing the weather between September and June, September generally experiences warmer temperatures with a minimum of 24°C (75°F) and an average of 28°C (82°F), in contrast to June, which has a slightly cooler minimum of 22°C (71°F) and an average of 26°C (79°F). While the maximum temperatures in both months are similar, September is typically drier, receiving 210 mm (8.3 in) of precipitation compared to June's 403 mm (15.9 in). Interestingly, despite having the same number of rainy days (20), June has a higher humidity level at 86%, slightly surpassing September's humidity of 82%. For comprehensive details on June weather, check out China weather in June.
In comparing the weather patterns of September and July, both months exhibit similar average temperatures, hovering around 28°C (82°F), with maximum temperatures reaching 30°C (86°F) in September and slightly higher at 30°C (87°F) in July. However, September tends to be rainier, with a notable increase in precipitation to 210 mm (8.3 in) over 20 days, compared to July's 174 mm (6.8 in) spread across just 11 days. Additionally, humidity levels are slightly lower in July at 86%, compared to September's 82%, resulting in a more humid feel during the peak of summer. For a closer look at typical July weather patterns, you can refer to this detailed resource: China weather in July.
In comparing the weather between September and August, both months exhibit a similar average temperature of around 28°C (82°F), with maximum temperatures reaching 30°C (86°F) in September and 30°C (87°F) in August. However, September experiences slightly cooler minimum temperatures, averaging 24°C (75°F), compared to August's minimum of 25°C (78°F). Interestingly, September sees significantly higher precipitation, with 210 mm (8.3 in) over 20 days, compared to August's 152 mm (6.0 in) over 14 days. Both months maintain a consistent humidity level at 82%, but September’s increased rainfall suggests a shift towards more unsettled weather. For more detailed insights on August weather, visit China weather in August.
In comparing the weather between September and October, it's evident that October offers slightly cooler temperatures, with minimums dipping to 21°C (70°F) compared to September's 24°C (75°F). The average temperature decreases from 28°C (82°F) in September to 26°C (78°F) in October, while maximum temperatures also show a subtle decline from 30°C (86°F) to 29°C (84°F). Precipitation in October is significantly less, totaling 142 mm (5.6 in) over 13 days, compared to September's 210 mm (8.3 in) across 20 days. Humidity remains fairly consistent, dropping slightly from 82% in September to 80% in October. For those interested in more detailed weather patterns, visit China weather in October.
In September, the weather is noticeably warmer, with average temperatures reaching around 28°C (82°F) and maximums often hitting 30°C (86°F). This month experiences significant rainfall as well, with about 210 mm (8.3 in) of precipitation falling over 20 days, resulting in high humidity levels at 82%. In contrast, November sees a drop in temperatures, with a cooler average of 23°C (73°F) and maximums that peak at 27°C (80°F). Additionally, precipitation in November is reduced to 112 mm (4.4 in) over just 11 days, accompanied by a slight decrease in humidity to 79%. For those interested in detailed information on weather patterns in November, here's more on China weather in November.
In September, the weather is notably warmer, with average temperatures around 28°C (82°F) and humidity levels reaching 82%. This month experiences significant rainfall, accumulating 210 mm (8.3 in) over about 20 days, making it quite a wet period. In contrast, December sees a much cooler climate, with average temperatures dropping to 19°C (67°F) and a maximum of 25°C (77°F). The precipitation decreases to 135 mm (5.3 in) over 15 days, and humidity levels are also lower at 75%. For more insights on December weather, you can check out China weather in December.
As summer transitions into autumn, September in China showcases a delightful shift in weather patterns. With temperatures peaking at a comfortable 30°C, the climate tends to be milder compared to the scorching summer months. However, it's also the season when humidity reaches its zenith, coupled with frequent rainfall, making for a lush and vibrant atmosphere. While the average temperature of 28°C and occasional precipitation create a refreshing ambiance, it contrasts sharply with the dry and more intense heat experienced in July and August. As you navigate through this month, the enchanting blend of warmth and moisture stands out, offering a unique experience distinct from other times of the year. For a deeper understanding of how these conditions compare year-round, explore China Climate.