September Weather in Nanjing, China

Last updated: August 21, 2025

September in Nanjing, China heralds a transition into autumn, marked by warm temperatures averaging around 28°C (82°F), with peaks reaching a sizzling 35°C (96°F). Nighttime offers a respite with lows of 21°C (70°F), creating a comfortable environment for evening activities. However, be prepared for frequent rain, as the month brings 151 mm (5.9 in) of precipitation over 18 days, creating a humid atmosphere at 71%. This blend of warmth and moisture characterizes September as a vibrant and dynamic period in Nanjing, where the beauty of the city can be enjoyed despite the occasional rain shower.

September Temperature in Nanjing

As September unfolds in Nanjing, China, the temperatures begin to transition from the sweltering summer heat into the more moderate fall climate. With a minimum of 21°C (70°F) and an average soaring to 28°C (82°F), it still retains some warmth, but not the oppressive peaks of summer. The maximum temperature reaches a comfortable 35°C (96°F), making it the tail end of a hot season yet hinting at the cooler weather to come. This month showcases a pattern where temperatures are gradually mellowing, with a noticeable drop from the scorching highs of July and August. Such a shift not only brings relief but also invites locals and visitors alike to enjoy outdoor activities in the vibrant landscapes of the city. As the days grow shorter and crisper, September in Nanjing acts as a gentle bridge between the extremes of summer and the refreshing embrace of autumn.

September Weather in Nanjing: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Nanjing, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Nanjing, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec606066727982848382777063
Data source: Temperature data for Nanjing generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Nanjing

September in Nanjing, China, marks a transitional phase in the weather pattern, featuring 151 mm (5.9 in) of rainfall across 18 days. This significant amount of precipitation, while lower than the summer months of July and August, indicates a continued prevalence of wet conditions as the region gradually moves from the intense summer heat into the cooler autumn. Compared to previous months, September sees less rain than the peak levels in June (264 mm) and August (278 mm), suggesting a tapering off of the monsoons. The moisture remains vital for replenishing the landscape, setting the stage for the drier months ahead. Overall, the month encapsulates the lingering warmth of late summer while hinting at the approaching fall climate.

September Precipitation Trends in Nanjing

The chart displays monthly precipitation patterns in Nanjing, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Nanjing, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec22366073139264171278151983933
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Nanjing

As September arrives in Nanjing, China, the humidity levels drop to 71%, signaling a subtle transition from the sweltering summer months. After peaking during May and July at 85%, the climate begins to offer a reprieve, with September presenting a refreshing balance similar to January’s humidity levels. This decrease heralds the onset of autumn, as moisture gradually diminishes into the cooler months ahead. The trend illustrates how Nanjing experiences a gradual decrease in humidity post-summer, moving towards October's 70% and beyond, making for a more pleasant and comfortable atmosphere as the city embraces the changing seasons.

September Average Humidity in Nanjing

This chart illustrates the average monthly humidity levels in Nanjing, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Nanjing is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%73%79%80%85%81%85%84%72%70%72%75%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Nanjing

As September rolls into Nanjing, China, the UV Index remains notably high at 12, categorizing it as extreme and allowing just 10 minutes of unprotected sun exposure before burning occurs. This trend mirrors the previous months, with a strong emphasis on sunlight intensity that has persisted throughout the peak summer season. Although September marks a slight decrease from the peak UV Index of 13 seen in the summer months, the sun's rays still demand respect. Like the earlier summer months, safety precautions such as sunscreen and protective clothing are essential. To stay informed and protect yourself effectively, you can check the detailed forecast at Nanjing UV Index.

Maximum UV Index Levels in Nanjing for September

The chart shows the monthly maximum UV Index (UVI) for Nanjing in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Nanjing typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec710121213131313121097
Data source: Nanjing September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Nanjing

As the vibrant month of September unfolds in Nanjing, China, the city basks in 290 hours of sunshine, a delightful continuation of the summer's warmth. This figure reflects the consistency in sunny days following the peak of July, which boasts an impressive 326 hours. Although slightly lower than the 299 hours of sunlight enjoyed in August, September still offers a generous dosage of golden rays. The transition from summer to autumn is evident, yet the sunlight lingers, ensuring that Nanjing remains bright and lively as it gradually shifts towards the cooler months. With this trend of abundant sunshine, residents and visitors alike can relish the beautiful blend of warmth and fall colors before the days become shorter.

Monthly Sunshine Duration in Nanjing: September Highlighted

The September sunshine duration represents the total number of hours Nanjing experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec214h256h270h268h290h260h326h299h290h279h260h264h
Data source: Nanjing September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Nanjing During September

As September rolls into Nanjing, the likelihood of sunny weather presents a refreshing contrast to the preceding summer months. With a 50% chance of sunshine, September marks a turn towards more favorable weather compared to the bleak clouds of June and August, which see chances plummet to 9% and 18%, respectively. While early autumn brings a moderate optimism for clearer skies, it's noteworthy that this month enjoys a significant upswing from the 44% in April, hinting at a transition where nature begins to reclaim its brilliance post-summer. This shift not only enhances outdoor activities but also offers a perfect backdrop for enjoying the vibrant foliage as the season advances.

Percentage of Sunny Days in September in Nanjing

The chart illustrates the percentage of sunny days in Nanjing throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Nanjing experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec69%61%48%44%28%9%28%18%50%36%68%53%
Data source: Nanjing September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Nanjing in September

As September unfolds in Nanjing, China, the city experiences 12 hours of daylight, mirroring the length seen in the previous spring months of March and April. This consistency signals the gradual transition from the long, sunlit days of summer, which peaked at 13 hours in May, June, and July. Although daylight hours begin to wane in October, with a drop to 11 hours, September still retains a comfortable brightness that invites outdoor activities and exploration. The month's daylight duration sets a serene tone, perfect for enjoying the change of seasons as autumn approaches.

Average Daylight Hours in Nanjing for September

The chart illustrates the variation in daylight duration in Nanjing throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 51m11h 21m12h12h 41m13h 15m13h 31m13h 23m12h 53m12h 15m11h 35m11h10h 43m
Data source: Nanjing daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Nanjing

In September, the winds of Nanjing take on a gentle quality, with an average speed dipping to 1.8 m/s (4 mph), marking it as the calmest month of the year. This soft breeze contrasts sharply with the stronger gusts of the following month, October, which sees a notable increase to 3.1 m/s (7 mph). Throughout the summer, wind speeds steadily decline, with July and August reporting the lowest figures, creating a stillness that pairs with the lingering summer heat. As the seasons begin to turn, the decrease in September's winds signals a transition towards autumn, inviting a more tranquil atmosphere in this historic city.

Average September Wind Speed in Nanjing

The chart displays monthly wind speed patterns in Nanjing, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.82.42.52.72.82.62.22.01.8 m/s3.12.92.9
Data source: Nanjing September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Nanjing Compares to Other Months

Weather in Nanjing varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Nanjing, focusing on differences in temperature, rainfall, humidity, and UV levels.

September and January present striking contrasts in weather. In September, temperatures soar with a minimum of 21°C (70°F) and an average of 28°C (82°F), reaching highs of 35°C (96°F). This month also sees significant precipitation, with 151 mm (5.9 in) of rainfall over 18 days, contributing to a high humidity level of 71%. Conversely, January offers a much cooler climate, with temperatures ranging from a minimum of 2°C (37°F) to an average of 16°C (60°F), peaking at 28°C (82°F). Rainfall is minimal during this month, amounting to only 22 mm (0.9 in) over just 3 days, while the humidity remains consistent at 71%. For more detailed information, you can visit Nanjing weather in January.

September and February present a stark contrast in weather patterns. In September, temperatures range from a warm minimum of 21°C (70°F) to a scorching maximum of 35°C (96°F), with an average of 28°C (82°F). The month is also characterized by considerable rainfall, totaling 151 mm (5.9 in) over 18 days, and humidity levels at 71%. In contrast, February experiences much cooler temperatures, with a minimum of just 4°C (39°F) and an average of 16°C (61°F), peaking at 28°C (83°F). Precipitation is significantly lower in February, averaging 36 mm (1.4 in) over only 5 days, with a slightly higher humidity level of 73%. For a more detailed look at February's weather, visit Nanjing weather in February.

In September, the weather is typically warm, with temperatures ranging from a minimum of 21°C (70°F) to a maximum of 35°C (96°F), and an average temperature of 28°C (82°F). This month is characterized by high humidity levels at 71% and considerable rainfall, receiving about 151 mm (5.9 in) over 18 days. In contrast, March brings cooler conditions, with temperatures ranging from a minimum of 8°C (47°F) to a maximum of 32°C (90°F), averaging 19°C (67°F). The month sees significantly less rainfall at 60 mm (2.4 in) over just 9 days, along with a slightly higher humidity level of 79%. For more detailed information, you can check Nanjing weather in March.

In September, the weather tends to be warmer and more humid, with temperatures ranging from a minimum of 21°C (70°F) to a maximum of 35°C (96°F) and an average of 28°C (82°F). This month also experiences significant rainfall, totaling 151 mm (5.9 in) across approximately 18 days. In contrast, April offers a much cooler climate, with temperatures ranging from a minimum of 11°C (53°F) to a maximum of 33°C (91°F) and an average of 22°C (72°F). The precipitation in April is lighter, at 73 mm (2.9 in) over about 10 days, and while its humidity is slightly higher at 80%, it feels less oppressive than the mugginess of September. For more information on April weather, you can visit Nanjing weather in April.

In comparing the weather between September and May, it is evident that both months experience warm temperatures, but with some notable differences. September offers a minimum temperature of 21°C (70°F) and an average of 28°C (82°F), while May starts cooler with a minimum of 15°C (60°F) and an average of 26°C (79°F). However, May can reach higher maximum temperatures, peaking at 38°C (100°F), compared to September's max of 35°C (96°F). Precipitation levels are somewhat similar, with September receiving 151 mm (5.9 in) over 18 days and May seeing 139 mm (5.5 in) over 16 days. Humidity is also higher in May at 85%, compared to 71% in September, making May feel more oppressive. For more specific insights, you can refer to Nanjing weather in May.

In comparing the weather of September and June, both months exhibit warm temperatures, with September having a slightly lower minimum at 21°C (70°F) compared to June's 22°C (73°F). The average temperatures are similar, with September averaging 28°C (82°F) and June at 28°C (83°F). However, June tends to be more humid, with a humidity level of 81% compared to September's 71%. Precipitation also varies significantly, as June experiences more rainfall at 264 mm (10.4 in) over 24 days, while September sees 151 mm (5.9 in) over 18 days. For a deeper dive into June's climate conditions, you can check Nanjing weather in June.

When comparing the weather in September and July, there are several notable differences. September experiences slightly cooler temperatures, with a minimum of 21°C (70°F) and an average of 28°C (82°F), compared to July's minimum of 25°C (76°F) and average of 29°C (85°F). The maximum temperature in July reaches 37°C (99°F), which is notably higher than September's peak of 35°C (96°F). Additionally, July sees more precipitation at 171 mm (6.7 in) over 23 days, whereas September has 151 mm (5.9 in) across 18 days. Humidity levels are also higher in July at 85%, compared to 71% in September. For more detailed information, you can check Nanjing weather in July.

In comparing the weather between September and August, September offers slightly cooler temperatures with a minimum of 21°C (70°F) and a maximum of 35°C (96°F), in contrast to August's minimum of 24°C (76°F) and peak of 37°C (99°F). Average temperatures in September hover around 28°C (82°F), while August averages at 29°C (84°F). Rainfall is notably lower in September, with 151 mm (5.9 in) over 18 days compared to August's 278 mm (10.9 in) over 25 days. Additionally, humidity decreases from 83% in August to 71% in September, creating a slightly more comfortable atmosphere as summer transitions to fall. For more details on August weather, you can visit Nanjing weather in August.

September weather is characterized by warmer temperatures, with a minimum of 21°C (70°F) and an average of 28°C (82°F), while October brings cooler conditions, featuring a minimum temperature of 14°C (58°F) and an average of 25°C (77°F). Despite sharing the same maximum temperature of 35°C (96°F), October experiences significantly less precipitation at 98 mm (3.9 in) over just 7 days compared to September's 151 mm (5.9 in) over 18 days. Both months maintain similar humidity levels, hovering around 70-71%. For more detailed insights, you can explore Nanjing weather in October.

In September, the weather is considerably warmer, with average temperatures reaching 28°C (82°F) and highs peaking at 35°C (96°F). The month is also marked by significant rainfall, totaling 151 mm (5.9 in) over 18 days, contributing to a humid feel with a humidity level of 71%. In contrast, November experiences a significant drop in temperature, averaging around 21°C (70°F) with a maximum of 31°C (88°F), while the minimum temperature plummets to 12°C (53°F). Additionally, November sees much less rainfall, with only 39 mm (1.5 in) recorded over just 3 days, and the humidity remains nearly the same at 72%. For more details on November's climate, you can refer to Nanjing weather in November.

September and December present a striking contrast in weather characteristics. September typically features warm temperatures, with a minimum of 21°C (70°F) and an average high reaching 35°C (96°F), while December offers a much cooler atmosphere, with temperatures ranging from a low of 7°C (45°F) to a high of 29°C (84°F). Additionally, September experiences considerable rainfall, averaging 151 mm (5.9 in) over 18 days, compared to December's drier climate with only 33 mm (1.3 in) of precipitation over 4 days. Humidity levels remain relatively high in both months, though September averages 71%, slightly lower than December's 75%. For a more detailed look at December's weather, you can visit Nanjing weather in December.

Compare Nanjing's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Nanjing

In September, Nanjing experiences a transition from the sweltering summer heat to a more temperate climate, with maximum temperatures gradually beginning to decline while maintaining a warm average. As the month progresses, the city sees increased humidity and higher chances of rain, with nearly half the month experiencing precipitation. This combination creates a unique weather pattern that is both invigorating and refreshing, distinguishing September from the hotter summer months. For those planning a visit, understanding this shift can enhance your experience in this vibrant city. For more detailed insights on weather patterns, check out Nanjing Climate.