Last updated: August 28, 2025
In September, Hoi An experiences warm tropical weather, with daytime maximum temperatures reaching up to 34°C (94°F) and an average temperature around 29°C (84°F). The month is characterized by high humidity, averaging at 88%, creating a sultry atmosphere for residents and visitors alike. Rainfall is significant, with 246 mm (9.7 in) of precipitation distributed over approximately 23 rainy days. While the frequent showers can create a picturesque setting, travelers should be prepared for sudden downpours as they explore this charming city known for its well-preserved ancient architecture and vibrant culture.
In September, Hoi An experiences a pleasant temperature range, making it a delightful time to visit. The average temperature hovers around 29°C (84°F), with daytime highs reaching up to 34°C (94°F). This slight dip from the peak summer months indicates the transition into fall, as minimum temperatures settle at 25°C (77°F). The soothing warmth invites travelers to explore the picturesque streets and vibrant culture of this ancient town, while the humidity remains manageable compared to the scorching summer. As the month progresses, expect a blend of sunny days and occasional rain, perfect for marveling at Hoi An's enchanting lantern-lit evenings.
In September, Hoi An experiences a significant surge in precipitation, with an impressive 246 mm (9.7 in) of rainfall over 23 days. This marks a stark contrast to the months preceding it, as the rainfall sharply increases compared to August’s 142 mm and July’s 146 mm. The rainy season is in full swing, laying the groundwork for October’s even heftier downpour, which averages 533 mm. As September transitions into October, the intensity and frequency of rain continue to rise, highlighting a trend of increasing moisture that characterizes this vibrant coastal town's weather patterns during the autumn months. Such conditions not only nourish the lush landscapes but also create a unique ambiance, attracting visitors eager to experience Hoi An's enchanting atmosphere, rain or shine.
As September rolls into Hoi An, Vietnam, humidity levels peak at an impressive 88%, making it one of the most humid months of the year. Following a gradual climb from the more comfortable figures of 75% in April, humidity remains consistently high throughout the summer months, with July and August both hovering around 85% to 87%. This trend continues into October, when humidity reaches a stifling 90%. Visitors should be prepared for the sweltering weather of September, as it positions itself at the start of the monsoon season, promising a mix of tropical heat and occasional rain. The lush landscapes and vibrant culture, however, make Hoi An a captivating destination despite the rising humidity.
As September rolls into Hoi An, Vietnam, the UV Index remains notably high at 13, indicating an extreme exposure category with a burn time of just 10 minutes. This trend of elevated UV levels is consistent throughout the year, peaking in the spring months of March and April with an Index of 14 and 15, respectively. Even as the temperature begins to cool in October, the UV Index only slightly dips to 12, so travelers should remain vigilant. Whether you're exploring the historic streets or basking on the beaches, it's essential to take sun safety precautions seriously during this time. For more detailed insights, visit Hoi An UV Index.
UV Risk Categories
In September, Hoi An basks in an impressive 302 hours of sunshine, marking a vibrant transition from the bustling summer months. Following the peak brilliance of May with 329 hours, the sun begins to mellow, yet September remains radiant, maintaining a delightful warmth for visitors. The city's captivating charm is enhanced by the lingering summer glow, making it an ideal time for exploring ancient streets or enjoying riverside cafes. As the year progresses, sunlight hours gradually decrease, with October seeing 273 hours, but September stands out for its balance of warmth and stunning light, promising memorable experiences in this enchanting Vietnamese town.
In Hoi An, Vietnam, the likelihood of sunny weather tends to dwindle as summer fades into autumn, with September registering a modest 23% chance of sun. This trend reflects a broader shift in weather patterns, as the city's sunniest months are typically earlier in the year, peaking in February at 55%. Notably, the arrival of the rainy season is felt in the latter half of the year, with August dipping to 22%, only slightly improving in October to 14%. Therefore, while September might offer some glimpses of sunshine, it is wise to prepare for the possibility of grey skies and rain as the month transitions towards the wetter autumn months.
As September rolls into Hoi An, the city enjoys a delightful 12 hours of daylight, continuing a trend that began in spring. This consistency in daylight duration reflects the region’s tropical climate, where daylight remains abundant throughout the year. After a peak of 13 hours in June, the daylight hours gently taper off, offering a serene balance between sun and shade. This steady illumination not only enhances the charm of Hoi An’s ancient streets but also invites travelers to immerse themselves in its captivating culture and natural beauty as the days transition into the cooler months of autumn.
As September arrives in Hoi An, Vietnam, the wind begins to pick up gently, with an average speed of 2.8 m/s (6 mph). This marks a subtle transition from the warmer summer months, where breezes were slightly lighter. Interestingly, September's winds maintain a steady pace, setting the stage for the upcoming months when gusts begin to strengthen, peaking at 3.8 m/s (8 mph) in December. This rhythmic increase in wind speed not only heralds the arrival of the cooler autumn but also adds an invigorating freshness to the air, enhancing the charm of Hoi An’s picturesque landscapes and vibrant street life. As the year unfolds, the winds in Hoi An tell a story of nature's progression, weaving through the fabric of local culture and daily life.
Weather in Hoi An varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Hoi An, focusing on differences in temperature, rainfall, humidity, and UV levels.
In September, Hoi An experiences noticeably warmer weather, with temperatures ranging from a minimum of 25°C (77°F) to a maximum of 34°C (94°F), and an average of 29°C (84°F). The month is characterized by high humidity at 88% and significant rainfall, with a total precipitation of 246 mm (9.7 in) spread over 23 days. In contrast, January presents a cooler and drier climate, featuring temperatures that range from a minimum of 16°C (61°F) to a maximum of 28°C (84°F) and an average of 22°C (73°F). The precipitation reduces to 161 mm (6.4 in) over 19 days, with humidity slightly lower at 86%. For more details, you can check Hoi An weather in January.
The weather in September is markedly warmer and more humid compared to February. September boasts average temperatures around 29°C (84°F), with highs reaching up to 34°C (94°F), while February's temperatures range from a minimum of 16°C (61°F) to an average of 22°C (73°F). Additionally, September experiences significantly higher precipitation, with 246 mm (9.7 in) over 23 days, compared to February's 84 mm (3.3 in) over just 12 days. Despite being a little drier, February maintains a comfortable humidity level at 83%, just slightly lower than September's 88%. For more detailed information on February's weather, you can visit Hoi An weather in February.
In September, the weather is typically hot and humid, with temperatures ranging from a minimum of 25°C (77°F) to a maximum of 34°C (94°F) and an average of 29°C (84°F). This month also experiences significant rainfall, receiving 246 mm (9.7 in) over 23 days, contributing to a high humidity level of 88%. In contrast, March sees milder temperatures, with minimums of 19°C (67°F), averages of 25°C (77°F), and maximums of 31°C (89°F). Precipitation drops to 80 mm (3.2 in) over just 11 days, allowing for more comfortable humidity at 78%. For more details on the weather in March, you can visit Hoi An weather in March.
In September, the weather is markedly warmer and more humid compared to April, with minimum temperatures starting at 25°C (77°F) and averaging 29°C (84°F), while the humidity peaks at 88%. This month also experiences significantly higher rainfall, averaging 246 mm (9.7 in) over 23 days, resulting in a sultry atmosphere. In contrast, April sees milder temperatures, with a minimum of 20°C (69°F) and an average of 26°C (80°F), accompanied by lower humidity at 75% and much less precipitation, totaling just 79 mm (3.1 in) over 10 days. For more detailed insights on April weather, you can check Hoi An weather in April.
In comparing the weather of September and May, September tends to be slightly more humid with an average humidity of 88%, compared to May's 80%. Both months have similar average temperatures at 29°C (84°F), but May can reach higher maximum temperatures of 36°C (96°F), making it feel hotter on the warmer days. September experiences significantly more rainfall, with 246 mm (9.7 in) across 23 days, while May has only 108 mm (4.3 in) over 14 days, resulting in drier conditions. For a detailed look at what to expect during this season, you can check out Hoi An weather in May.
In comparing the weather between September and June, we observe distinct differences in temperature and precipitation patterns. September experiences slightly cooler temperatures, with a minimum of 25°C (77°F) and a maximum of 34°C (94°F), averaging around 29°C (84°F), while June typically sees a minimum of 26°C (78°F) and can peak at 37°C (98°F), with an average of 30°C (87°F). Notably, September is significantly wetter, receiving 246 mm (9.7 in) of rainfall over 23 days, in stark contrast to June's 69 mm (2.7 in) of precipitation over just 13 days. Humidity levels are also high in both months, with September at 88% and June at 85%. For more details on June weather in Hoi An, you can visit Hoi An weather in June.
In comparing the weather between September and July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 25°C (77°F) to a maximum of 34°C (94°F), while July experiences a higher average, with minimums of 26°C (79°F) and maximums reaching 36°C (97°F). Additionally, September sees significantly more rainfall, with a total precipitation of 246 mm (9.7 in) over 23 days, compared to July's 146 mm (5.8 in) over 18 days. The humidity remains relatively high in both months, at 88% in September and 85% in July. For more detailed information about July weather, you can visit Hoi An weather in July.
In September, the weather in Hoi An is characterized by slightly lower average temperatures, ranging from a minimum of 25°C (77°F) to a maximum of 34°C (94°F), compared to August, where temperatures can reach up to 36°C (97°F) with an average of 30°C (86°F). Additionally, September experiences significantly higher precipitation, with 246 mm (9.7 in) over 23 days, while August sees 142 mm (5.6 in) across 19 days. The humidity levels remain quite similar, with September at 88% and August at 87%. For more detailed insights, you can check Hoi An weather in August.
In September, the weather tends to be warmer with temperatures ranging from a minimum of 25°C to a maximum of 34°C, averaging around 29°C. The month also experiences significant rainfall, with a total precipitation of 246 mm over 23 days and a humidity level of 88%. In contrast, October sees slightly cooler temperatures with a minimum of 23°C and a maximum of 32°C, averaging 27°C. However, it is also much wetter, with a substantial increase in precipitation to 533 mm over 25 days and humidity rising to 90%. For more detailed insights, you can check Hoi An weather in October.
In September, the weather is typically warmer, with average temperatures ranging from a minimum of 25°C (77°F) to a maximum of 34°C (94°F), while November sees cooler temperatures, averaging between 21°C (71°F) and 30°C (85°F). However, November has significantly higher precipitation, with a total of 596 mm (23.5 in) falling over 23 days, compared to September's 246 mm (9.7 in) across the same number of days. Humidity also increases slightly from September's 88% to November's 91%. For more details on the specific weather patterns during this time, check out Hoi An weather in November.
In September, the weather is characterized by warmer temperatures, with a minimum of 25°C (77°F) and an average of 29°C (84°F), peaking at 34°C (94°F). The month also sees substantial rainfall, accumulating 246 mm (9.7 in) over 23 days, coupled with high humidity at 88%. In contrast, December experiences milder temperatures, where the minimum dips to 18°C (64°F) and the average falls to 23°C (73°F), with a maximum of 28°C (83°F). However, December is even wetter, with 355 mm (14.0 in) of precipitation spread over 24 days, while humidity remains high at 89%. For more details on the specific weather patterns in December, you can visit Hoi An weather in December.
As September arrives in Hoi An, the weather shifts to a more humid and rainy phase compared to the drier months that precede it. With average temperatures hovering around a warm 29°C (84°F), days often feel muggy due to the high humidity levels of 88%. Rainfall becomes a significant feature, as the city experiences up to 23 days of precipitation, amounting to an average of 246 mm (9.7 in) of rain throughout the month. While the sun may still make an appearance, visitors should be prepared for sudden downpours that can transform the landscape. For a more detailed understanding of what to expect, be sure to check out Hoi An Climate.