Last updated: August 21, 2025
September in Si'an, China is characterized by warm temperatures and notable humidity. With maximum temperatures reaching 34°C (94°F) and an average of 24°C (76°F), the month offers a pleasant contrast to the lingering summer heat. However, it is not without its challenges, as the city experiences an average of 142 mm (5.6 in) of rainfall across 11 days, creating a lush, vibrant atmosphere. Coupled with humidity levels around 79%, September's weather invites exploration while reminding visitors to prepare for sudden showers.
In September, Si'an, China experiences a delightful transition as summer wanes, with temperatures averaging around 24°C (76°F). The month begins with warm evenings, featuring minimums of 16°C (61°F), and reaches a comfortable maximum of 34°C (94°F) during the day. This gradual cool-down not only brings relief from the sweltering heat of August but also marks the onset of a more temperate climate, setting the stage for the crisp air of autumn to come. As the month progresses, the consistent warmth and reduced humidity make September an ideal time for outdoor activities and exploring the rich cultural heritage of this historic city.
In September, Si'an witnesses a significant drop in precipitation compared to the preceding summer months, yet it remains substantial at 142 mm (5.6 in), falling in line with the typical trend of increased rainfall from May to August. With 11 days of rain this month, the weather remains versatile, supporting the lush greenery that flourishes post-summer. This dip from the heavy summer rains marks a transition towards a drier season, hinting at the onset of autumn, where monthly averages further decline. Overall, September’s precipitation reflects a balance; while it’s less than July’s staggering total of 231 mm (9.1 in), it still delivers ample moisture, crucial for the region's agricultural cycles.
In September, Si'an, China experiences a noticeable shift in humidity, dropping to 79% after a humid summer peak. This decline marks a transition from the sweltering 95% in July and 92% in August, signaling the end of the oppressive heat. As the landscape begins to cool, the humidity levels recede, yet still remain higher than the earlier months of the year, such as 67% in January and 69% in February. This consistent humidity throughout the warmer months underscores Si'an's subtropical climate, where moisture levels tend to peak in the summer before gradually tapering off into the autumn.
As September rolls into Si'an, China, residents and visitors should prepare for a very high UV Index of 10, accompanied by a burn time of just 15 minutes. This marks a slight drop from the extreme levels seen in both July and August, where exposure times shortened to a mere 10 minutes in peak summer. Leading up to September, the index has shown a consistent pattern of high levels, with values reaching 10 or above from April through August. Looking ahead, October will see a decrease to an 8, but the trend underscores the importance of sun safety during these months. For detailed information on UV radiation in the area, check out Si'an UV Index.
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September in Si'an, China, is a delightful continuation of the summer's warmth, boasting a commendable 268 hours of sunshine. This month gracefully follows August's peak of 308 hours, which means while the sunny days are slightly less abundant, they still provide ample opportunities to bask in the golden rays. As the year transitions from the sweltering heights of summer, September's sunlight maintains a strong presence compared to the earlier months; it showcases a steady decline from summer's zenith yet remains brighter than the cooler, cloudier months ahead. With October bringing 246 hours of sunshine, the gradual shift into autumn is palpable, but September's lingering warmth creates a perfect backdrop for exploration and outdoor activities.
In Si'an, China, September marks a notable shift in weather patterns, with a 45% chance of sunny days. This increase in sunshine is refreshing compared to the mid-summer slump, where chances dip to a mere 21% in July. As the month follows the typically warmer and cloudier days of June and July, September offers a pleasant transition, leading into the more favorable sunny months of November and December, which boast chances of 60% and 62%, respectively. Overall, if you're seeking brighter skies, September stands out as one of the better months for enjoying sunshine in Si'an, making it an excellent time for outdoor activities and exploration.
In Si'an, China, the daylight duration exhibits a captivating rhythm throughout the year. September, with its 12 hours of daylight, marks a gentle transition from the longer days of summer. As the months progress from the vibrant 14 hours in June to September's milder offering, a noticeable decline sets in, echoing the shift towards autumn. This trend sees October and November bringing shorter days, with only 11 and 10 hours, respectively, signaling the onset of winter. The alternating pattern showcases not only the changing seasons but also invites residents to savor the lingering warmth of late summer before embracing the cosier, shorter days ahead. With each month, Si'an mirrors the natural ebb and flow of daylight, creating a unique backdrop for life and activities in this historical city.
As the summer heat begins to wane, September in Si'an, China greets residents with a refreshing average wind speed of 3.6 m/s (8 mph), mirroring the breezy conditions of earlier months like January and March. This consistency in wind speed offers a gentle transition from the stronger gusts of July, which peak at 4.5 m/s (10 mph), down to the calmer periods of late fall. Notably, September marks a rebound from the noticeably lighter winds of August, where the average dipped to 2.9 m/s (7 mph). Overall, the month blends a comfortable warmth with a refreshing breeze, making it an ideal time for outdoor activities as nature prepares for the cooler days ahead.
Weather in Si'an varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Si'an, focusing on differences in temperature, rainfall, humidity, and UV levels.
September presents a warm and humid climate, with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 34°C (94°F) and an average of 24°C (76°F). The month experiences significant rainfall, totaling 142 mm (5.6 in) over 11 days, contributing to the high humidity of 79%. In stark contrast, January showcases a much colder environment, with temperatures dipping as low as -8°C (17°F) and averaging just 5°C (41°F). The maximum in January reaches only 18°C (64°F), accompanied by considerably less precipitation—47 mm (1.8 in) over 8 days—and lower humidity at 67%. For a deeper look into January weather conditions, you can refer to Si'an weather in January.
September and February exhibit strikingly different weather patterns. In September, temperatures range from a minimum of 16°C (61°F) to a maximum of 34°C (94°F), creating a warm average of 24°C (76°F). This month also experiences considerable rainfall, with 142 mm (5.6 in) spread over 11 days and higher humidity at 79%. Conversely, February presents a cooler climate, with temperatures dropping to a minimum of -5°C (23°F) and reaching a maximum of 24°C (75°F), resulting in a much lower average of 6°C (43°F). Precipitation in February is significantly reduced to 52 mm (2.0 in) over just 8 days, accompanied by lower humidity levels at 69%. For a detailed look at weather conditions in February, you can visit Si'an weather in February.
The weather in September is notably warmer and more humid compared to March, with average temperatures ranging from 16°C (61°F) at night to a scorching 34°C (94°F) during the day. In contrast, March offers much cooler temperatures, with a minimum of 0°C (33°F) and an average of 11°C (51°F), peaking at 27°C (81°F). Additionally, September experiences significantly higher precipitation at 142 mm (5.6 in) over 11 days, while March sees a modest 56 mm (2.2 in) spread across 9 days. Despite the difference in temperature and precipitation, both months share the same humidity level at 79%. For more detailed insights, you can check Si'an weather in March.
September and April showcase contrasting weather patterns. September features warmer temperatures, with a minimum of 16°C (61°F), an average of 24°C (76°F), and highs reaching up to 34°C (94°F). The month also experiences more rainfall, totaling 142 mm (5.6 in) over about 11 days, accompanied by a humidity level of 79%. In contrast, April presents cooler conditions, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 30°C (87°F) and an average of 15°C (59°F). This month has less precipitation at 70 mm (2.8 in) over 8 days, along with a slightly higher humidity of 86%. For more detailed information about April weather, visit Si'an weather in April.
September and May display distinct weather patterns, with September generally warmer on average but more humid. In September, temperatures range from a minimum of 16°C (61°F) to a maximum of 34°C (94°F), while May offers cooler temperatures, fluctuating between 9°C (49°F) and 35°C (95°F). Precipitation is higher in September, with 142 mm (5.6 in) over 11 days compared to May's 112 mm (4.4 in) over 9 days. Although May has slightly higher humidity at 87%, September's humidity level is notably high at 79%. For a detailed look at the climate in May, check out Si'an weather in May.
September and June present similar temperature ranges, with both months featuring a minimum of 16°C (61°F) and an average of 24°C (76°F). However, June tends to be hotter, reaching a maximum temperature of 37°C (99°F) compared to September's 34°C (94°F). Additionally, June experiences slightly lower precipitation at 131 mm (5.2 in) over 10 days, versus September's 142 mm (5.6 in) over 11 days. The humidity is also higher in June at 90%, compared to September's 79%, making June feel more muggy and oppressive. For more details on June weather, visit Si'an weather in June.
In comparing the weather between September and July, we see a noticeable shift in temperatures and precipitation patterns. September experiences milder temperatures, with a minimum of 16°C (61°F) and an average of 24°C (76°F), compared to July's warmer minimum of 18°C (65°F) and average of 28°C (82°F). July is characterized by higher maximum temperatures that can reach up to 39°C (103°F), while September peaks at 34°C (94°F). Additionally, July sees significantly more rain, with 231 mm (9.1 in) over 17 days, in contrast to September's 142 mm (5.6 in) over 11 days. Humidity levels are also higher in July at 95%, compared to September's 79%. For more detailed information on July's weather, check Si'an weather in July.
In comparing the weather for September and August, it is evident that September experiences cooler temperatures with a minimum of 16°C (61°F) and an average of 24°C (76°F), while August is notably warmer, with a minimum of 21°C (71°F) and an average of 28°C (84°F). Moreover, August has higher maximum temperatures, reaching up to 37°C (99°F) compared to September's maximum of 34°C (94°F). Although September sees a reduction in precipitation days, with 11 days of rainfall totaling 142 mm (5.6 in), August is rainier, with 14 days of rain and a total of 192 mm (7.6 in). Additionally, the humidity level is higher in August at 92%, compared to 79% in September. For more details on August's weather, you can visit Si'an weather in August.
In September, the weather tends to be warmer and more humid, with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 34°C (94°F) and an average of 24°C (76°F). This month also sees a significant amount of rainfall, totaling 142 mm (5.6 in) over about 11 days, coupled with a humidity level of 79%. In contrast, October brings cooler temperatures, with a minimum of 8°C (47°F), an average of 19°C (66°F), and a maximum of 32°C (90°F). Precipitation is notably reduced to 58 mm (2.3 in) over just 7 days, and humidity drops slightly to 76%. For more details, check out Si'an weather in October.
September typically experiences much warmer temperatures than November, with an average of 24°C (76°F) compared to November's cooler average of 13°C (56°F). The temperature range in September spans from a mild 16°C (61°F) to a hot 34°C (94°F), while November sees a low of 1°C (34°F) and a maximum of 27°C (81°F). Additionally, September tends to be much wetter, with 142 mm (5.6 in) of precipitation over 11 days, whereas November has a significantly lower rainfall of 53 mm (2.1 in) over just 7 days. Humidity levels remain relatively similar, hovering around 79% in September and 77% in November. For more detailed weather information about November in Si'an, you can visit Si'an weather in November.
September and December present stark contrasts in weather. September boasts a warm climate with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 34°C (94°F), averaging 24°C (76°F). It also experiences significant rainfall, with 142 mm (5.6 in) over 11 days, resulting in a high humidity level of 79%. In contrast, December brings a chillier atmosphere, with temperatures dropping significantly to a minimum of -7°C (20°F) and reaching a maximum of 20°C (68°F), averaging only 7°C (45°F). Precipitation decreases to 44 mm (1.7 in) over 8 days, and humidity levels slightly lower to 73%. The difference in weather between these two months highlights the seasonal transition from warmth to winter. For more details on December weather in Si'an, check Si'an weather in December.
As September arrives in Si'an, the weather begins to transition, offering a delightful mix of warmth and humidity. With average temperatures hovering around a pleasant 24°C (76°F), this month stands out from the hotter summer months, while still retaining a hint of summer's warmth. The notable humidity level of 79% adds a tropical feel, complemented by a moderate amount of precipitation spanning about 11 days. This shift in weather patterns prepares the region for the cooler autumn months ahead, making September a unique time to experience Si'an’s vibrant landscape. For more insights into Si'an's climate, explore Si'an Climate.