September Weather in Nanjing, China

Last updated: August 21, 2025

September in Nanjing, China, offers a dynamic climate as summer transitions to autumn. With maximum temperatures reaching up to 36°C (97°F) and an average of 24°C (76°F), the month is characterized by warm days. However, the evenings cool off with a minimum temperature of 15°C (60°F), providing a pleasant respite. Despite these warm conditions, September experiences 86 mm (3.4 in) of rainfall over approximately 10 days, contributing to the high humidity level of 75%. This blend of warmth and moisture makes September a vibrant yet humid month in Nanjing, perfect for exploring the city's rich cultural heritage.

September Temperature in Nanjing

In September, Nanjing experiences a pleasant transition as summer begins to wane. The minimum temperature settles at a comfortable 15°C (60°F), while the average rises to a temperate 24°C (76°F), reflecting the lingering warmth of late summer. As the city enjoys maximum temperatures reaching up to 36°C (97°F), residents and visitors alike can appreciate the vibrant outdoor activities before the cooler autumn air sets in. This month strikes a balance between warmth and refreshment, making it an ideal time to explore Nanjing’s historic sites and enjoy its lush scenery. With temperatures steadily declining from the sweltering highs of August, September marks a unique period of relaxation and transition in this bustling city.

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).
JanFebMarAprMayJunJulAugSepOctNovDec394354627278838476645543
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 brings a notable shift in weather patterns, as the city experiences 86 mm (3.4 in) of rainfall over 10 days. This amount, while less than the peak summer months of July and August, still contributes to the lingering humid atmosphere typical of late summer. With precipitation showing a decline from August's substantial 189 mm (7.4 in), September serves as a transitional phase, easing the intense summer downpours but still ensuring the city remains lush and vibrant. As autumn approaches, the rainfall begins to taper off, setting the stage for drier months ahead, yet offering enough moisture to keep the greenery thriving.

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.
JanFebMarAprMayJunJulAugSepOctNovDec5352666914315722818986544440
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Nanjing

In Nanjing, China, September brings a slight reprieve from the sweltering summer humidity, with levels dropping to 75%. This month marks a transition from the peak of summer, where July and August boast humidity around 90% and 88% respectively. The gradual decline in moisture levels is a refreshing change as autumn approaches, following a pattern where humidity tends to peak in the hotter summer months. As the city's climate shifts, September humidity still remains relatively high but provides a hint of the cooler, drier days that October will soon offer, with only a gentle increase to 76%. Overall, this month illustrates a significant reduction from the summer's grip, setting the stage for the upcoming seasonal changes.

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.
JanFebMarAprMayJunJulAugSepOctNovDec70%73%82%86%85%85%90%88%75%76%84%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Nanjing

As summer fades in Nanjing, September maintains a very high UV Index of 10, similar to the intense levels observed in the preceding months of June, July, and August. With a burn time of just 15 minutes, this month continues the trend of elevated UV exposure, emphasizing the need for protective measures when outdoors. The lingering warmth signals the transition towards slightly lower indexes in October, where a moderate decline to 8 is anticipated. Emphasizing the importance of awareness and protection against UV rays, September encourages residents and visitors alike to stay informed and shield themselves from the sun's potent rays. For more detailed insights, check out the 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.
JanFebMarAprMayJunJulAugSepOctNovDec568101011111010854
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

September in Nanjing is a delightful blend of late summer warmth and early autumn charm, boasting approximately 254 hours of sunshine. This marks a noticeable decline from the peak summer months of July and August, which bathe the city in 287 and 296 hours of golden rays respectively. As the days grow shorter and cooler, sunlight in September still outshines the earlier months of the year, showcasing a consistent trend of increasing brightness leading up to the warmest months. With May and June also offering impressive sunshine totals, it’s clear that Nanjing enjoys a vibrant stretch of sunny days in the warmer seasons, making September a perfect time for both locals and visitors to soak in the last remnants of summer.

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.
JanFebMarAprMayJunJulAugSepOctNovDec159h214h237h242h275h277h287h296h254h233h223h216h
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 unfolds in Nanjing, the likelihood of sunny weather reflects a promising 49% chance of sunshine, mirroring the sunny outlook of January. This marks a notable shift from the summer months, where the odds of clear skies dip considerably, with July and August experiencing just 24% and 35% respectively. As the sweltering heat begins to wane, September invites a refreshing transition with a resurgence of brightness that starts to rival the sunnier days of the autumn months ahead. This pattern highlights the city's unique climate, where early fall often brings a delightful balance of warmth and sunshine, making it an ideal time for outdoor activities and exploration.

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.
JanFebMarAprMayJunJulAugSepOctNovDec49%45%26%28%29%29%24%35%49%42%62%68%
Data source: Nanjing September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Nanjing in September

In Nanjing, China, September marks a transition as the summer days begin to wane, offering around 12 hours of daylight. This duration reflects a gradual decline from the peak of 14 hours in June, with the daylight hours slowly tapering off as autumn approaches. Following a summer filled with long, bright days in June and July, September presents a slightly shorter yet still generous amount of sunlight, reminiscent of the 13-hour days in August. As the month progresses, the city prepares for the crispness of October, which will bring about further reductions in daylight, settling back to 11 hours. This pattern underscores the rhythmic ebb and flow of seasonal change, inviting residents and visitors alike to savor the last golden hours of summer before embracing the cooler months ahead.

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 17m11h 1m11h 59m12h 57m13h 47m14h 12m13h 59m13h 16m12h 20m11h 21m10h 30m10h 4m
Data source: Nanjing daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Nanjing

As September arrives in Nanjing, the average wind speed gently hovers at 2.9 m/s (6 mph), reflecting a shift towards the calmness of autumn. This month’s breeze is a slight reprieve from the peak summer winds, which reached 3.4 m/s in July. Following a gradual decline through the sweltering summer months, the winds in September mirror the spring's lightness earlier in the year. Notably, September's winds are notably stronger than August's lull at 2.4 m/s, hinting at a subtle transition that lingers in the air, reminiscent of the seasonal shift that invites a refreshing change. With October maintaining this same serene pace, the consistent winds serve as a gentle reminder of nature's cyclical rhythm transitioning from the heat of summer to the cooler embrace of autumn.

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.
JanFebMarAprMayJunJulAugSepOctNovDec3.03.43.12.92.82.53.42.42.9 m/s2.93.02.6
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 stark contrasts in weather. In September, temperatures range from a minimum of 15°C (60°F) to a maximum of 36°C (97°F), with an average of 24°C (76°F), creating a warm and humid atmosphere with 75% humidity and 86 mm (3.4 in) of precipitation over about 10 days. In contrast, January experiences much cooler temperatures, with a minimum of -10°C (13°F) and a maximum of 18°C (64°F), averaging only 4°C (40°F). This winter month sees lower precipitation at 53 mm (2.1 in) over 8 days and a slight drop in humidity to 70%. For more detailed insights into the winter weather, visit Nanjing weather in January.

In September, the weather is warm with temperatures ranging from a minimum of 15°C (60°F) to a scorching maximum of 36°C (97°F), averaging around 24°C (76°F). The month sees significant humidity at 75% and experiences around 86 mm (3.4 in) of precipitation over 10 days. In contrast, February presents a stark shift, featuring much colder temperatures with a minimum of -11°C (13°F) and a maximum of 26°C (79°F), averaging just 6°C (43°F). Although February has slightly lower precipitation at 52 mm (2.0 in) over 9 days, the humidity level remains relatively close at 73%. For more detailed information on February conditions, visit Nanjing weather in February.

September and March exhibit distinct differences in weather patterns. September tends to be warmer, with average temperatures ranging from a minimum of 15°C (60°F) to a maximum of 36°C (97°F) and an average of 24°C (76°F). In contrast, March is much cooler, with temperatures ranging from a chilly 0°C (31°F) to a maximum of 29°C (84°F) and an average of 12°C (54°F). Despite both months experiencing around 10 days of rainfall, September receives more precipitation, totaling 86 mm (3.4 in), compared to March's 66 mm (2.6 in). Additionally, humidity levels are slightly higher in March at 82%, while September has a humidity of 75%. For more insights into the conditions during March, check out Nanjing weather in March.

September and April showcase distinct weather patterns, highlighting the transition from summer to autumn and from winter to spring. September features warmer temperatures, with a minimum of 15°C (60°F), an average of 24°C (76°F), and a high of 36°C (97°F). In contrast, April temperatures are cooler, with a minimum of 5°C (41°F), an average of 17°C (62°F), and a maximum of 32°C (90°F). While September experiences more rainfall with 86 mm (3.4 in) over 10 days, April has slightly less precipitation at 69 mm (2.7 in) over 9 days. Additionally, humidity levels are higher in April at 86%, compared to 75% in September. For more details, you can refer to Nanjing weather in April.

When comparing the weather in September and May, we observe notable differences in temperature, humidity, and precipitation. September generally enjoys warmer temperatures, with an average of 24°C (76°F) and a maximum reaching up to 36°C (97°F), while May has a slightly cooler average of 22°C (72°F), despite also having the potential for similar high temperatures. In terms of precipitation, May experiences a higher total of 143 mm (5.6 in) over 9 days, compared to September's 86 mm (3.4 in) across 10 days, suggesting that May is generally wetter. Humidity levels are also higher in May at 85%, compared to 75% in September, contributing to a more humid atmosphere during the late spring. For more specific details, you can check the full breakdown of Nanjing weather in May.

September weather shows a slight decrease in temperature compared to June, with minimums of 15°C (60°F) in September versus 17°C (62°F) in June. The average temperature in September is 24°C (76°F), while June sees a warmer average of 26°C (78°F). Interestingly, both months experience the same maximum temperature of 36°C (96°F in June and 97°F in September). However, September has significantly less precipitation at 86 mm (3.4 in) compared to June's 156 mm (6.2 in), even though both months have rainfall on about 10 days. Humidity remains relatively high in both months, with September at 75% and June at 85%. For more details, you can check Nanjing weather in June.

In comparing the weather between September and July, September generally experiences milder temperatures, with a minimum of 15°C (60°F) and an average of 24°C (76°F), compared to July's warmer minimum of 19°C (67°F) and an average of 28°C (83°F). July also boasts higher maximum temperatures, reaching up to 38°C (101°F), whereas September peaks at a maximum of 36°C (97°F). Additionally, July sees significantly more rainfall, with 228 mm (9.0 in) over 18 days, compared to September's 86 mm (3.4 in) over just 10 days. Humidity levels are also higher in July at 90%, compared to September's 75%. For more detailed information on July's weather, visit Nanjing weather in July.

In comparing the weather of September and August, September presents a more moderate climate with an average temperature of 24°C (76°F), while August experiences higher temperatures averaging 29°C (84°F). Although the maximum temperature in September can reach up to 36°C (97°F), it remains slightly cooler than August's peak of 38°C (100°F). Precipitation also decreases significantly in September, totaling 86 mm (3.4 in) over 10 days, compared to the 189 mm (7.4 in) over 14 days in August. Additionally, humidity levels are slightly lower in September at 75%, while August maintains a higher humidity of 88%. For a detailed look at August weather, please visit Nanjing weather in August.

September weather is characterized by higher average temperatures, with minimums around 15°C (60°F) and an average of 24°C (76°F), while October sees a notable drop, with minimums plummeting to 7°C (45°F) and an average of 18°C (65°F). Despite both months sharing a maximum temperature of 36°C (97°F), October’s cooler temperatures contribute to a more refreshing atmosphere. Precipitation is also reduced in October, dropping to 54 mm (2.1 in) over 7 days compared to September's 86 mm (3.4 in) over 10 days, though humidity remains relatively stable at 76%. For more detailed weather insights, visit Nanjing weather in October.

September and November present notably different weather patterns. In September, temperatures range from a minimum of 15°C (60°F) to a maximum of 36°C (97°F), with an average of 24°C (76°F). This month experiences higher precipitation levels of 86 mm (3.4 in) over about 10 days, combined with a humidity of 75%. In contrast, November sees cooler temperatures, with a minimum of 0°C (32°F) and an average high of 28°C (83°F), resulting in an overall average of 13°C (55°F). The month also has less rainfall, totaling 44 mm (1.7 in) across 6 days, and a slightly higher humidity of 84%. For a detailed forecast, you can check Nanjing weather in November.

In September, the weather is warm with temperatures ranging from a minimum of 15°C (60°F) to a maximum of 36°C (97°F), and an average of 24°C (76°F). This month experiences higher precipitation of 86 mm (3.4 in) over about 10 days, coupled with a humidity level of 75%. In stark contrast, December brings much cooler weather, with temperatures dipping to a minimum of -7°C (20°F) and reaching a maximum of 20°C (68°F), averaging only 6°C (43°F). Precipitation decreases to 40 mm (1.6 in) over 7 days, and humidity remains slightly higher at 77%. For more detailed information on December weather, check out Nanjing weather in December.

Compare Nanjing's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Nanjing

As September unfolds in Nanjing, the weather begins to shift, offering a refreshing change from the peak summer heat. With average temperatures settling comfortably around 24°C (76°F), it serves as a pleasant transition from the sizzling highs of July and August. The humidity remains relatively high at 75%, but the sporadic rainfall, totaling about 86 mm over ten days, brings welcome relief and helps to rejuvenate the lush landscapes. This month marks the gradual onset of autumn, making it a delightful time to explore the city’s natural beauty and cultural heritage. For a deeper dive into Nanjing's climate throughout the year, visit Nanjing Climate.