Last updated: August 21, 2025
In September, Ya'an, China welcomes the transition into autumn with average temperatures hovering around 20°C (69°F), peaking at a comfortable 31°C (88°F) and dipping to a cooler 13°C (56°F) at night. This month is notably wet, with a substantial precipitation total of 202 mm (7.9 in) spread over 22 days, making it one of the rainier periods of the year. Humidity levels soar to an impressive 91%, enhancing the lush landscape that Ya'an is renowned for. Whether you're basking in the mild warmth or braving the frequent showers, September in Ya'an offers a rich tapestry of weather conditions that contribute to its unique charm.
In September, Ya'an, China experiences a pleasant transition from summer's warmth into the early hints of autumn chill. With minimum temperatures around 13°C (56°F) and averages settling at a comfortable 20°C (69°F), residents enjoy mild weather ideal for outdoor activities. The mercury can soar up to a maximum of 31°C (88°F), showcasing a lingering summer presence. This month marks a shift from the intense heat of August, which boasts similar maximum temperatures but higher average conditions. As September unfolds, the gradual cooling prepares the landscape for vibrant autumn hues, making it a favorite time for locals and travelers alike to explore the stunning natural beauty that surrounds this charming city.
In September, Ya'an experiences a significant precipitation total of 202 mm (7.9 in), marking it as one of the wetter months of the year, albeit milder than the torrential rains of August, which averages a remarkable 381 mm (15.0 in). With rain falling on about 22 days, the month sustains a consistent...yet less intense pattern, positioning it within a transitional phase, hinting at the lingering monsoonal influences before the drier months ahead. This trend illustrates a clear shift from the peak rainy season, with September's precipitation dropping noticeably, yet still contributing to the region's lush landscape in preparation for the oncoming autumn.
In September, Ya'an, China, experiences a high humidity level of 91%, maintaining the elevated humidity trend that begins in the summer months. This consistent moisture in the air can be observed from July through September, where levels peak, creating a lush environment often associated with the region's rich biodiversity. Interestingly, this peak in humidity follows a gradual increase from February’s 87% and parallels a slight decrease into October at 90%. The overall year-round humidity exhibits a dynamic pattern, fluctuating between the mid-70s and low-90s, with summer and early autumn marked by a distinct spike that enhances the region's character.
In September, Ya'an experiences a consistently high UV Index of 12, placing it in the extreme exposure category with a burn time of just 10 minutes. This trend aligns with the preceding months of summer, where UV levels peaked similarly, highlighting a seasonal pattern that emphasizes the need for sun protection. As the year transitions towards autumn with October showing a slight decrease to a UV Index of 9, individuals in Ya'an should remain vigilant about their sun exposure during September. To learn more about UV levels throughout the year, visit Ya'an UV Index.
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September in Ya'an, China, experiences a notable shift in sunshine hours, with 208 hours basking in warmth—markedly lower than the vibrant summer months. After enjoying a peak of 288 hours in March, the daylight gradually begins to decline, making way for the cooler autumn air. This decline in sunshine reflects a broader trend, as September often heralds the transition to less sunny days, with October further decreasing to 192 hours. Yet, despite this reduction, September remains a picturesque time, where crisp sunlight filters through golden leaves, offering a serene glimpse of nature's beauty as it prepares for the impending winter months.
In September, Ya'an, China experiences a moderate chance of sunny weather, with about 20% likelihood for clear skies. While this marks a slight increase compared to the summer months, such as August and June, it is still below the sunniest months like January and November. Notably, the sunny disposition of September suggests a transition towards brighter days as the region slowly shifts into autumn. Despite this modest chance of sunshine, it reflects a broader trend of variability throughout the year, highlighting the unique climatic patterns Ya'an exhibits. As the days grow cooler, those seeking a glimpse of sunlight will find a refreshing opportunity in this early fall month.
As September unfolds in Ya'an, China, daylight begins to subtly wane, offering about 12 hours of light—significantly less than the 14 hours enjoyed during the summer months of June and July. This gradual transition marks a shift from the vibrant brightness of late spring and summer, where daylight peaks at its longest, to the cozy, shorter days that characterize the autumn. Following September, daylight continues to decline, dropping to 11 hours in October, before settling into a cycle of shorter days through the winter months. This natural cadence invites residents and visitors alike to embrace the changing seasons, highlighting autumn's arrival and its palette of colors and experiences.
As September arrives in Ya'an, China, the average wind speed settles at a gentle 1.1 m/s (3 mph), maintaining a consistent breeze that has characterized the summer months. This light wind flow mirrors a gradual tapering off from the slightly higher speeds observed earlier in the year, where winds hovered between 1.2 m/s and 1.3 m/s during the first half. Notably, July and August experienced a slight dip, with speeds dropping to 1.1 m/s (2 mph), marking a transition towards the calmer feel of early autumn. As the year progresses, this trend of softening winds continues into October, reinforcing the serene and tranquil atmosphere that envelops Ya'an as nature prepares for the quiet of winter.
Weather in Ya'an varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Ya'an, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly contrasting weather conditions. In September, temperatures range from a mild minimum of 13°C (56°F) to a warm maximum of 31°C (88°F), with an average temperature of 20°C (69°F). This month experiences considerable rainfall, totaling 202 mm (7.9 in) over 22 days, accompanied by high humidity levels at 91%. In contrast, January brings a colder climate, with temperatures dropping to a minimum of -4°C (25°F) and peaking at only 15°C (60°F), resulting in an average of 5°C (41°F). Precipitation in January is significantly lower, at 50 mm (2.0 in) over 15 days, and the humidity is slightly lower at 86%. For more details on January conditions, you can check Ya'an weather in January.
In comparing the weather of September and February, a clear contrast emerges between the two months. September boasts a warm average temperature of 20°C (69°F), reaching highs of 31°C (88°F), while February experiences much cooler conditions, with an average of 7°C (45°F) and a maximum of only 21°C (70°F). Additionally, September is characterized by significant humidity at 91% and heavy rainfall, with 202 mm (7.9 in) of precipitation over 22 days, making it one of the wetter months. In contrast, February sees much lighter precipitation of 60 mm (2.4 in) over 14 days and slightly lower humidity at 87%. For more specific weather details in February, you can refer to the link: Ya'an weather in February.
September and March present contrasting weather patterns, highlighting the transition between seasons. In September, temperatures range from a minimum of 13°C (56°F) to a maximum of 31°C (88°F), with an average of 20°C (69°F). The month is characterized by significant precipitation, totaling 202 mm (7.9 in) over 22 rainy days and high humidity at 91%. In contrast, March experiences cooler temperatures, with a minimum of 1°C (34°F) and a maximum of 26°C (80°F), averaging 12°C (54°F). Precipitation is notably lower in March, at 79 mm (3.1 in) over 19 days, and humidity also decreases to 78%. For a more detailed look at the weather in March, check out Ya'an weather in March.
In September, the weather is generally warmer, with average temperatures reaching 20°C (69°F) and highs of up to 31°C (88°F), while April experiences cooler temperatures, with an average of 16°C (60°F) and a maximum of 29°C (85°F). September also sees significantly more rainfall, with 202 mm (7.9 in) over 22 days, compared to April's 149 mm (5.9 in) over 19 days. The humidity is notably higher in September at 91%, compared to 80% in April, making the latter month feel somewhat drier and more comfortable. For a more detailed look at April weather, you can check out Ya'an weather in April.
In comparing the weather between September and May, September tends to be warmer overall, with an average temperature of 20°C (69°F) versus May's 19°C (66°F). While both months experience high humidity, September is slightly more humid at 91%, compared to May's 87%. Interestingly, September receives more precipitation, totaling 202 mm (7.9 in) over 22 days, while May has 151 mm (6.0 in) over 18 days. This makes September feel wetter and somewhat stickier, despite the similar maximum temperatures, with September reaching up to 31°C (88°F) and May peaking at 30°C (86°F). For a detailed look at May's weather patterns, you can visit Ya'an weather in May.
In comparing the weather of September and June, we notice similar minimum temperatures, both averaging around 13°C (55°F to 56°F). June experiences slightly warmer average temperatures at 22°C (71°F) compared to September's 20°C (69°F). The maximum temperatures are also comparable, with June peaking at 32°C (89°F) and September reaching 31°C (88°F). However, September tends to be wetter, receiving 202 mm (7.9 in) of precipitation over 22 days, while June sees 152 mm (6.0 in) across 19 days. Despite the higher humidity levels in September at 91% compared to June's 89%, both months exhibit a trend of warm temperatures and significant rainfall. For more detailed insights, check Ya'an weather in June.
When comparing the weather between September and July, notable differences emerge. September tends to be cooler, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 31°C (88°F), averaging around 20°C (69°F). In contrast, July presents warmer temperatures, with a minimum of 18°C (64°F) and a maximum reaching 34°C (94°F), averaging 24°C (75°F). Both months experience significant rainfall, with September receiving 202 mm (7.9 in) over 22 days, while July is wetter, accumulating 259 mm (10.2 in) across 23 days. Additionally, humidity levels in September soar to 91%, slightly higher than July's 89%. For more detailed information on July weather, you can check Ya'an weather in July.
In comparing the weather between August and September, September tends to be cooler with average temperatures ranging from a minimum of 13°C (56°F) to a maximum of 31°C (88°F), while August experiences higher temperatures, with a minimum of 17°C (62°F) and a maximum of 34°C (93°F). Additionally, September sees a significant decrease in precipitation compared to August, with 202 mm (7.9 in) over 22 days, compared to August's total of 381 mm (15.0 in) across 24 days. Interestingly, humidity remains consistent in both months at 91%, contributing to a rather muggy atmosphere. For more information on August weather, you can visit Ya'an weather in August.
September and October present a noticeable shift in weather patterns. September typically boasts warmer temperatures, with daily averages reaching up to 20°C (69°F) and maximums soaring as high as 31°C (88°F). In contrast, October sees a decline in temperatures, averaging around 15°C (59°F) with maximums peaking at 27°C (82°F). Precipitation is more frequent in September, totaling 202 mm (7.9 in) over 22 days, compared to 151 mm (5.9 in) over 26 days in October. Despite the decrease in rainfall, October maintains a high humidity level at 90%, slightly less than September's 91%. For more details on October weather, you can check Ya'an weather in October.
September's weather is typically much warmer than November's, with average temperatures ranging from a minimum of 13°C (56°F) to a high of 31°C (88°F). In contrast, November sees significantly cooler conditions, with temperatures dropping to a low of 2°C (36°F) and peaking at 22°C (72°F). Additionally, September experiences higher precipitation with 202 mm (7.9 in) over 22 days, while November has considerably less rainfall at 70 mm (2.8 in) across 17 days. Despite the differences in temperature and rainfall, both months maintain a high humidity level of 91%. For more insights, check Ya'an weather in November.
September and December showcase a stark contrast in weather conditions. September experiences warmer temperatures, averaging around 20°C (69°F) with highs reaching up to 31°C (88°F). The month is characterized by high humidity at 91% and significant rainfall, totaling 202 mm (7.9 in) over 22 days. In contrast, December brings colder weather, with an average temperature of just 6°C (43°F), dipping as low as -5°C (24°F) at times. Precipitation decreases to 61 mm (2.4 in) across 16 days, and humidity remains relatively low at 87%. For more details on December weather, you can visit Ya'an weather in December.
September in Ya'an marks a transition from the warm summer months to the cooler autumn season. With increased humidity and frequent rain, this month experiences notably higher precipitation compared to drier periods, making it a lush and vibrant time for the region. While the days can still feel summery with temperatures reaching a maximum of 31°C, the average drop signifies the onset of cooler nights and the refreshing change of the season. This blend of warmth interspersed with rain sets September apart from the drier summer months, creating a unique and enchanting climate. For those looking to explore more about Ya'an's weather, visit Ya'an Climate.