Sichuan Weather in September

1. Sichuan Basin in the eastern part of the province experiences the transitional period from summer to autumn, with slowly dropping temperatures and moderate rainfall. 

2. The weather of northwestern Sichuan is cool and rainy, but the landscape is no less impressive. 

3. Southwestern Valley has a warm and rainy climate, but the rain usually falls in the night. 

4. September is a shoulder season in Sichuan. 

Long Sea in Jiuzhaigou

The climate of the Sichuan Basin is gradually cooling down in September. In the first half of the month, you see highs ranging from 28 to 31 degrees Celsius (82-88 degrees Fahrenheit) in Chengdu. When the sun reaches its peak, the highest temperature can get to 34°C (93°F), showing a feeling of summer heat. In the second half, daily high temperatures drop to around 24-28°C (75-82°F).  
 

It’s worth noting that there is a huge temperature gap between day and night, and you may feel quite cool in the early morning and late afternoon. If you encounter a rainy and windy day, the lowest temperature may plunge to only 15 degrees Celsius (59 degrees Fahrenheit), which requires an extra layer to keep warm. 

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Chengdu Weather in September
Jiuzhaigoug Weather in September
 

September marks the end of the rainy season in the Sichuan Basin. For example, Chengdu sees moderate rainfall, with 119 mm over 16 rainy days. Saying that, you don’t have to worry about rainy days affecting your travel plans, as these showers usually don’t last for too long or fall heavily. Also, during the rainy periods, you can shift to indoor attractions, such as Sanxingdui Museum and Jinsha Site Museum.

Due to the warm and rainy climate, Sichuan Basin experiences a rather humid environment in September. The average humidity level of Chengdu remains around 81%, and visitors may feel a little muggy especially around the noon time. 
 

Sichuan Basin in September is dominated by overcast days in September, so the sunlight hours are shortened, with 5-6 hours on average. However, that doesn’t mean you can totally ignore the sunshine: the maximum UV level can reach 9, which means sunscreen is still necessary. 
 

Northwestern Plateau in September also experiences a growingly cool climate. Due to its high altitude, its weather is obviously cooler than Sichuan Basin’s. In the first half of the month, summer vibes are still lingering, with highs generally ranging from 23 to 28°C (73-82°F). When the sun is right overhead during mid-day, visitors would feel hot, with the highest temperature once recorded 34°C (93°F). Towards the second half, daily high temperature usually hovers between 18 and 23°C (64-73°F). On rainy days, the perceived temperatures are slightly lower than forecast shows. 
 

In this region, there are also significant temperature differences between day and night, averaging about 15°C (59°F). Before 8:00 and after 16:00, the weather can be a bit cold, with the lowest temperature of 13°C (55°F). 
 

Rhino Lake in Jiuzhaigou

Northwestern Plateau in September has the most humid climate of the year, with an average humidity level of 74 %. Therefore, it’s essential to wear a quick-dry inner layer to stay comfortable. 
 

The average sunshine hours in northwestern Sichuan range from 3 to 6 hours per day in September. Around 9:00 to 11:00, if the weather is sunny, you’ll find the most stunning moment of Huohuahai Lake in Jiuzhaigou National Park: golden sunlight shatters into sparkling fragments on the lake’s extremely clear surface. 
 

The air is very thin in high altitudes, so be aware that ultraviolet radiation is intense. The maximum UV levels come to about 7, making sun-protective items essential. 
 

Southwestern Valley’s weather stays warm, with daily highs ranging from 28-31°C (82-88°F). However, before the sunrise and towards late night, the temperature goes down dramatically, with lows of 17-22°C (63-72°F). 
 

September is the rainy season in this area. For example, Panzhihua in September receives an average precipitation of 289 mm from 19 rainy days. Luckily, the rain usually falls at night, which rarely impacts your daily outings. 

Due to the hot temperatures and rainy weather, this area experiences a high humidity level: 80%. 

Flower Market in Panzhihua

Upper Clothing: For urban areas, it’s ok to wear t-shirts in breathable cotton-lined fabrics or light long-sleeved shirts during the daytime. When the dark falls, it’s wise to add a light jacket to stay cozy. If you intend to explore the highlands, try this outfit: quick-dry long-sleeved shirt, lightweight down jacket, and waterproof shell jacket. 
 

Bottom Clothing: In Eastern and Southwestern Sichuan, you can wear shorts, light summer pants, or dresses. But it’s best to wear waterproof hiking pants for the northwestern plateau areas. 
 

Footwear: A pair of comfortable sneakers goes with any place. Mountainous areas require nice hiking shoes, as wet steps can be a bit slippery after rain. 
 

Accessories: 

1. Sun-protective Items: Sunscreen, sunglasses and a bucket hat.

2. Rain Gear: an umbrella or a raincoat.
 

1. Northwestern Sichuan’s weather is rainy, so Jiuzhaigou boasts a high water level, crystal-clear lakes and spectacular waterfalls - highly recommended to travelers. 

2. By late September, temperatures on the northwestern plateau begin to cool, and trees and grasslands begin to change color, revealing the early autumn scenery. A visit to Daocheng Yading is highly recommended.

3. September can be considered as the shoulder season for tourists, as most schools start their new terms and visitor number drops a lot. Thus, you may have a relatively peaceful and budget-friendly travel experience. 

Crystal-clear Lake in Jiuzhaigou