Last updated: August 28, 2025
September brings a warm and humid atmosphere to Ly Son, Vietnam, with maximum temperatures reaching up to 34°C (93°F) and an average of 29°C (84°F). Visitors can expect minimum nighttime lows around 25°C (78°F), perfect for tropical evenings. However, this month also marks a significant period of rainfall, accumulating around 239 mm (9.4 in) over 22 days, contributing to the rich greenery of the island. With humidity levels soaring at 88%, it's advisable to stay hydrated and embrace the vibrant yet wet nature of Ly Son's September weather.
In September, Ly Son, Vietnam, experiences a warm transition into autumn, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 34°C (93°F). The average temperature settles at a comfortable 29°C (84°F), providing a pleasant climate ideal for outdoor exploration. This month marks a subtle shift from the hotter summer months, as the generally steady warmth gives way to slightly cooler evenings. The patterns observed in September mirror the gradual decline in maximum temperatures that begins to unfold as the region moves toward October, inviting visitors to enjoy the laid-back charm of this beautiful island.
September marks a notable increase in precipitation for Ly Son, Vietnam, with an impressive 239 mm (9.4 in) of rainfall recorded over 22 days. This surge contrasts sharply with the drier months preceding it; for example, August had 124 mm across 18 days. As the region transitions into the more humid autumn months, September signals the beginning of the wetter season, leading into even heavier rains in October and November, which each average over 400 mm. This trend illustrates how September serves as a pivotal point in the annual rainfall cycle for Ly Son, setting the stage for the region’s lush landscapes and vibrant ecosystems as they awaken from the summer heat.
In September, Ly Son, Vietnam experiences a spike in humidity, reaching 88%, marking the transition into the fall season. This increase is part of a broader trend observed throughout the year, where humidity levels gradually rise from the relatively drier months of April and May. Following the peak summer months of August—which sees humidity at 87%—September signals a shift towards the wetter months, with levels continuing to climb to 90% in October. Overall, the year unfolds a humid pattern, peaking in the autumn and winter months, reflecting the island's tropical climate. As the humidity rises, so does the lush beauty of the island, making Ly Son even more captivating to visitors.
In September, travelers to Ly Son, Vietnam, should be prepared for a UV Index of 13, categorizing exposure as extreme. This reflects a slight decrease from the peak levels seen in the summer months, yet the danger of skin damage remains significant, with a burn time of just 10 minutes. Notably, the UV Index during this month maintains a high standard typical of April through July, suggesting a trend of consistently elevated UV levels throughout the year. As such, sun protection remains essential for both locals and visitors. For more detailed information, check the comprehensive guide on the Ly Son UV Index.
UV Risk Categories
As September unfolds in Ly Son, Vietnam, locals and visitors alike bask in the warm embrace of sunshine, enjoying an impressive 303 hours of sunlight. This month's tally reflects a slight decline from the sun-soaked summer months of August, which boasted 321 hours, yet remains robust compared to the earlier part of the year. The trend showcases a gradual increase in daylight hours as the year progresses, peaking in the vibrant month of May with 334 hours, before transitioning back into the lush greens of fall. With September still basking in abundant sunlight, it stands as a perfect bridge between the lively summer and the more temperate autumn, inviting everyone to relish in the radiant beauty of this coastal paradise.
In September, the likelihood of sunny weather in Ly Son, Vietnam, takes a noticeable dip, with only 22% chance of sunshine. This marks a decline from the slightly more promising summer months of July and August, which hover around 31% and 24% respectively. As the season transitions towards fall, the sun becomes increasingly shy, with September boasting one of the lowest probabilities of clear skies throughout the year. It's a stark contrast to the earlier months, such as March with a 64% chance, highlighting a clear trend of diminishing sunshine as autumn approaches. This drop suggests that visitors should prepare for cloudier days if they plan to explore Ly Son in September.
In September, Ly Son, Vietnam enjoys a delightful 12 hours of daylight, reflecting a consistent trend throughout the year. Following the peak of 13 hours in June, daylight duration gently recedes back to 12 hours during the late summer months of July and August, creating a balanced rhythm as the seasons shift. As the year progresses towards its end, daylight hours gradually diminish again to 11 hours in October, establishing a cyclical pattern that characterizes this stunning coastal locale. This steady interplay of light not only marks the passage of time but also enhances the vibrant scenery and daily life that thrives in Ly Son.
As September rolls in on the picturesque shores of Ly Son, Vietnam, the average wind speed settles at a gentle 3.4 m/s (8 mph), a subtle breeze that invites locals and visitors alike to bask in the island's tranquil beauty. The wind patterns reveal a notable trend; following a brief dip during the summer months, September's winds begin to pick up slightly, hinting at the shift towards a more invigorating autumn. This smooth transition leads into the robust gusts of November and December, where speeds noticeably increase, reaching 5.0 m/s (11 mph) and 5.7 m/s (13 mph) respectively. In contrast, the summer months display a lull, with July and August recording the lowest speeds, emphasizing September's role as a bridge to the more dynamic winds of the coming months. In essence, this serene breeze in September offers not just a moment of stillness, but also a promise of the lively autumn days ahead.
Weather in Ly Son varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Ly Son, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present contrasting weather patterns. In September, temperatures are significantly warmer, with a minimum of 25°C (78°F) and an average of 29°C (84°F), peaking at 34°C (93°F). This warm weather is accompanied by high humidity at 88% and considerable rainfall, totaling 239 mm (9.4 in) over 22 days. Conversely, January offers a cooler climate, featuring a minimum of 18°C (65°F) and an average temperature of 23°C (75°F), with a maximum of 27°C (81°F). Precipitation is lighter in January, with 139 mm (5.5 in) across 19 days, and slightly lower humidity at 86%. For more detailed information on January weather, visit Ly Son weather in January.
September and February present distinct contrasts in weather. In September, temperatures are generally warmer, with a minimum of 25°C (78°F) and an average high reaching up to 34°C (93°F). It is also a notably wet month, with a hefty precipitation of 239 mm (9.4 in) occurring over 22 days and humidity levels peaking at 88%. In contrast, February features milder weather, with temperatures ranging from a minimum of 18°C (64°F) to a maximum of 28°C (83°F). Precipitation is significantly lower at 67 mm (2.6 in), over just 12 days, and humidity is slightly reduced at 83%. This makes February a more comfortable time for outdoor activities compared to the steamy and rainy days of September. For more detailed information, you can check the Ly Son weather in February.
In September, the weather is significantly warmer and more humid compared to March, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 34°C (93°F) and an average of 29°C (84°F). This month also experiences heavy rainfall, with 239 mm (9.4 in) of precipitation over 22 days, leading to a humidity level of 88%. In contrast, March has milder temperatures that range from a minimum of 21°C (70°F) to a maximum of 30°C (87°F), averaging 26°C (78°F). Rainfall is considerably less in March, totaling only 48 mm (1.9 in) across 10 days, with lower humidity at 78%. For more details about weather specifics, you can refer to this link: Ly Son weather in March.
In September, the weather tends to be warmer and more humid compared to April, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 34°C (93°F), and an average of 29°C (84°F). The month experiences significant rainfall, with 239 mm (9.4 in) of precipitation spread over 22 days, leading to high humidity levels of around 88%. In contrast, April is generally cooler, with temperatures varying from a minimum of 21°C (71°F) to a maximum of 32°C (91°F) and an average of 27°C (81°F). Precipitation in April is much lighter, totaling only 56 mm (2.2 in) over 9 days, and the humidity is lower at 75%. For more detailed weather information, you can check out Ly Son weather in April.
September and May exhibit similar average temperatures, both hovering around 29°C (84°F), with maxima reaching 34°C (93°F). However, September is significantly wetter, receiving 239 mm (9.4 in) of rainfall over 22 days, compared to May's 57 mm (2.2 in) of precipitation over just 10 days. Additionally, the humidity levels are higher in September at 88%, while May experiences a slightly lower humidity of 80%. For a detailed look at weather conditions in Ly Son during this month, visit Ly Son weather in May.
In comparing the weather of September and June, September features slightly lower average temperatures, with a minimum of 25°C (78°F) and an average of 29°C (84°F), while June has a minimum of 26°C (79°F) and an average of 30°C (87°F). Both months experience high humidity levels, with September being a bit more humid at 88% compared to June’s 85%. Rainfall is notably higher in September, accumulating 239 mm (9.4 in) over 22 days, compared to June's 64 mm (2.5 in) across just 9 days. For more details, you can check Ly Son 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 (78°F) to a maximum of 34°C (93°F), while July experiences a warmer range with minimums at 26°C (80°F) and maximums reaching 35°C (95°F). Humidity levels are somewhat similar, with September at 88% and July slightly lower at 85%. However, September sees significantly more rainfall, with a staggering 239 mm (9.4 in) across 22 days, compared to July’s 108 mm (4.2 in) over 17 days. For more detailed insights, you can visit Ly Son weather in July.
In comparing the weather of September to August, we observe that September experiences slightly cooler average temperatures, with a minimum of 25°C (78°F) and an average of 29°C (84°F), compared to August's minimum of 26°C (78°F) and average of 30°C (86°F). While the maximum temperatures remain similar, with September reaching up to 34°C (93°F) and August peaking at 34°C (94°F), September is notable for significantly higher precipitation, totaling 239 mm (9.4 in) over 22 days, versus August's 124 mm (4.9 in) over 18 days. Additionally, humidity levels in September are slightly higher at 88% compared to August's 87%. For more detailed information, you can refer to Ly Son weather in August.
In September, the weather features warmer average temperatures, with a minimum of 25°C (78°F) and a maximum of 34°C (93°F), while October sees slightly cooler temperatures with a minimum of 24°C (75°F) and a maximum of 32°C (90°F). However, October experiences significantly higher precipitation, totaling 435 mm (17.1 in) over 25 days compared to September's 239 mm (9.4 in) over 22 days. The humidity remains relatively high in both months, increasing slightly in October to 90% from September's 88%. For a closer look at the October weather specifics in Ly Son, you can visit Ly Son weather in October.
In September, the weather is characterized by warmer temperatures, with a minimum of 25°C (78°F) and an average high of 34°C (93°F). The month experiences significant rainfall, totaling 239 mm (9.4 in) over 22 days, and relative humidity stands at 88%. In contrast, November brings cooler temperatures, with a minimum of 23°C (73°F) and an average maximum of 29°C (85°F). However, November sees even more precipitation, with 511 mm (20.1 in) spread over 26 days, and humidity increases slightly to 91%. For more details on this month's weather, check out Ly Son weather in November.
In September, the weather is typically warmer, with average temperatures ranging from a minimum of 25°C (78°F) to a maximum of 34°C (93°F), accompanied by high humidity levels of 88%. This month experiences significant rainfall, with a total of 239 mm (9.4 in) spread over 22 days. In contrast, December sees cooler temperatures, with averages between 19°C (67°F) and 29°C (84°F). Although December is still rainy, it has a slightly higher total precipitation of 302 mm (11.9 in) over 26 days, and humidity remains high at 89%. For a closer look at December's weather in this region, you can visit Ly Son weather in December.
September in Ly Son brings a notable shift in weather dynamics, marked by higher humidity levels that approach 88%, creating a tropical feel throughout the month. As the island transitions from the sweltering summer heat, you can expect temperatures averaging around 29°C (84°F), which feels quite warm especially with the frequent rain showers. With 239 mm of precipitation over 22 days, this month clearly stands out as one of the wetter periods of the year, contrasting with the drier months that precede it. For a detailed overview of the weather patterns throughout the year, visit Ly Son Climate.