Last updated: August 28, 2025
September in Mong Cai, Vietnam offers a warm tropical climate, with maximum temperatures reaching up to 33°C (92°F) and an average of 28°C (83°F). As the month unfolds, visitors can expect a minimum temperature of around 24°C (75°F), making it a comfortable time for outdoor exploration. However, prepare for a significant amount of rainfall, with total precipitation amounting to 256 mm (10.1 in) over about 21 days. The humidity level sits at a high 78%, contributing to the lush, vibrant surroundings typical of this coastal region. Ideal for those who enjoy a mix of sunshine and occasional showers, September presents an enticing glimpse into Mong Cai’s unique climatic charm.
In September, Mong Cai experiences a warm embrace as temperatures start to stabilize, showcasing a notable dip from the peak summer heat. With a minimum of 24°C (75°F) and reaching a comfortable average of 28°C (83°F), the coastal city remains nicely temperate. The maximum temperature can soar up to 33°C (92°F), making it one of the warmer months of the year. This trend of warm yet bearable temperatures leads into the autumn, offering a pleasant climate that encourages outdoor exploration and vibrant local festivals. As humidity begins to ease, September serves as a delightful transition into the cooler months, inviting travelers to experience the unique charm of Mong Cai.
In September, Mong Cai experiences a notable shift in precipitation dynamics, receiving 256 mm (10.1 in) of rain over 21 days. This amount marks a substantial decrease from the deluge of 469 mm in August, yet it remains significant compared to earlier months like June and July. This trend highlights September as a transitional period, where the heavy monsoon rains begin to taper off, paving the way for the forthcoming drier months. As the region moves into October, a further reduction to 206 mm is expected, signaling the gradual retreat of the annual rainfall peak. Observing this pattern unveils Mong Cai's unique climate rhythm, oscillating between intense rainfall and refreshing reprieve.
In September, Mong Cai, Vietnam experiences a noticeable dip in humidity, averaging 78%, compared to the peak levels of 86% seen in July and August. Following the summer months, where humidity consistently rises, this slight decrease signals a transition towards the drier autumn months ahead. Despite this reduction, the humidity remains relatively high, reflecting the region's tropical climate that keeps the air moist throughout the year. This trend illustrates the characteristic ebb and flow of humidity in Mong Cai, reinforcing the lushness of the landscape and the vibrancy of the local ecosystem, while also hinting at the more comfortable conditions that October will bring with its lower average of 72%.
In September, Mong Cai experiences a notable UV Index of 13, classified as extreme, with a burn time of just 10 minutes. This trend continues the pattern established in the preceding months, where the UV levels have consistently hovered at extreme levels, particularly peaking in July and August at 14. Following the intense summer months, September remains a challenging time for sun exposure, urging residents and visitors alike to take precautions to protect their skin. As the year progresses into October, the UV Index slightly lowers to 11, but anyone venturing outdoors should remain vigilant. For additional details on UV levels and their implications, explore the comprehensive guide at Mong Cai UV Index.
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In September, Mong Cai, Vietnam, basks in the warm embrace of approximately 287 hours of sunshine, creating a perfect backdrop for outdoor adventures and exploration. This month continues the trend of abundant sunshine set by the summer months, notably peaking in May with 305 hours. The sun-drenched days gradually taper off as the year progresses, with October bringing 265 hours and a notable decline through the subsequent months. However, September still captures the essence of late summer warmth, encouraging locals and visitors alike to take advantage of the lingering bright days before the cooler months set in.
In Mong Cai, Vietnam, the likelihood of sunny weather in September shows a modest 32% chance, marking a slight improvement from the preceding months. This trend is particularly noteworthy as the summer months of June and August experience the lowest probabilities of sunshine, plummeting to 13% and 11%, respectively. As the region transitions into autumn, September offers a refreshing uptick compared to the summer lull, signaling an inviting opportunity for outdoor activities. Following September, the chances of sun gradually increase again in October and November, with percentages rising to 35% and 51%. Overall, while September may not guarantee bright blue skies, it certainly offers a more promising outlook as the sweltering heat gives way to cooler, sunnier days.
As September unfolds in Mong Cai, Vietnam, the daylight duration stabilizes at 12 hours, mirroring the sunny allure of the preceding months. This trend follows a summer peak in May through July, where residents bask in an abundance of 13 hours of sunlight each day. As autumn approaches, daylight gradually diminishes, setting the stage for shorter days ahead in October and November. The pattern reflects the region's transition from the vibrant summer to a more subdued autumn, inviting a seasonal shift in both activity and ambiance. The steady rhythm of daylight duration not only shapes daily life but also underscores the inherent beauty of Mong Cai's changing seasons.
As September rolls into Mong Cai, the gentle caress of the wind becomes notably softer, with an average speed dipping to 2.3 m/s (5 mph). This marks a contrast to the preceding summer months when winds danced more briskly at speeds around 4.3 to 4.6 m/s (10 mph). The transition into autumn heralds a tranquil atmosphere, inviting locals and visitors alike to embrace the calmness that accompanies the change of seasons. Notably, as October approaches, a swift turnaround is on the horizon, with wind speeds projected to jump significantly to 6.0 m/s (13 mph), hinting at the dynamic shifts that characterize Mong Cai's climate throughout the year.
Weather in Mong Cai varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Mong Cai, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly different weather patterns. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 33°C (92°F), with an average of 28°C (83°F), creating a warm and humid atmosphere with 78% humidity. This month also experiences substantial rainfall, totaling 256 mm (10.1 in) over 21 days. In contrast, January offers a cooler climate, with temperatures starting at a minimum of 7°C (45°F), averaging 16°C (61°F), and peaking at 23°C (73°F). Rainfall is considerably reduced in January, totaling just 62 mm (2.4 in) over 10 days, accompanied by lower humidity at 66%. For more details about January weather, you can refer to Mong Cai weather in January.
September and February present contrasting weather patterns. In September, temperatures are significantly warmer, with a minimum of 24°C (75°F) and an average of 28°C (83°F), reaching highs of 33°C (92°F). Additionally, this month is characterized by heavy rainfall, accumulating 256 mm (10.1 in) over 21 days, and high humidity levels at 78%. In contrast, February offers a much cooler climate, with temperatures ranging from a low of 8°C (47°F) to a pleasant average of 17°C (63°F), peaking at 24°C (75°F). Rainfall is also considerably lighter in February, totaling 62 mm (2.5 in) across 11 days, and humidity is lower at 71%. For more detailed information on February weather, visit Mong Cai weather in February.
The weather in September is significantly warmer and more humid than in March. With average temperatures around 28°C (83°F) and maximums reaching up to 33°C (92°F), September experiences a higher minimum temperature of 24°C (75°F). In contrast, March sees cooler temperatures, with averages of 21°C (69°F) and maximums of 26°C (80°F), alongside a more comfortable minimum of 14°C (57°F). Additionally, September has considerably more precipitation, with 256 mm (10.1 in) spread over 21 days, compared to March's 84 mm (3.3 in) over 15 days. Despite having slightly lower humidity levels at 73%, March offers a more pleasant climate overall. For more details, you can check out Mong Cai weather in March.
When comparing the weather in September and April, it’s evident that September is typically warmer and wetter. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 33°C (92°F), with an average temperature of 28°C (83°F). The month experiences high precipitation levels, totaling 256 mm (10.1 in), and rain occurs on about 21 days, contributing to the humidity of 78%. In contrast, April features milder temperatures, with a minimum of 16°C (61°F) and a maximum of 29°C (85°F), averaging 23°C (74°F). Precipitation is significantly lower at 86 mm (3.4 in) over 14 days, leading to a slightly lower humidity of 71%. For more details on April weather, you can visit Mong Cai weather in April.
September and May offer contrasting weather experiences. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 33°C (92°F), with an average of 28°C (83°F). This month also sees significant rainfall, averaging 256 mm (10.1 in) over 21 days, coupled with high humidity levels at 78%. In contrast, May is slightly cooler, with temperatures varying from 19°C (67°F) to 32°C (90°F) and an average of 27°C (81°F). Precipitation is less intense in May, totaling 190 mm (7.5 in) over 19 days, and humidity is slightly lower at 76%. For more detailed insights about May weather, you can check Mong Cai weather in May.
In September, the weather is characterized by a minimum temperature of 24°C (75°F) and an average of 28°C (83°F), mirroring June's similar minimum of 23°C (74°F) and average of 29°C (84°F). Both months experience a maximum temperature of 33°C (92°F), though September sees slightly lower overall rainfall at 256 mm (10.1 in) compared to June's 265 mm (10.4 in). Precipitation occurs on 21 days in September versus 23 days in June, with humidity levels remaining fairly constant at 78% in September and 79% in June. For more detailed information, check out Mong Cai weather in June.
When comparing the weather in September and July, it is clear that both months experience high temperatures with averages around 28°C (83°F) in September and 29°C (84°F) in July. However, September tends to be slightly cooler with minimum temperatures at 24°C (75°F) compared to July's 26°C (78°F). Precipitation levels in July are significantly higher, with 364 mm (14.3 in) falling over 25 days, while September sees 256 mm (10.1 in) of rain over 21 days. Additionally, July has a higher humidity level at 86%, compared to September's 78%. For further details on July's weather, you can check out Mong Cai weather in July.
In comparing the weather between September and August, we see that September presents slightly lower temperatures, with a minimum of 24°C (75°F) and an average of 28°C (83°F), compared to August’s minimum of 25°C (78°F) and average of 29°C (84°F). Both months experience similar maximum temperatures, peaking at 33°C (92°F) in September and 33°C (91°F) in August. However, September is significantly drier, receiving only 256 mm (10.1 in) of precipitation over 21 days, while August is much wetter, with 469 mm (18.5 in) of rain over 26 days. Additionally, humidity levels are slightly lower in September at 78%, compared to a higher 86% in August. For more specific details, you can check this link: Mong Cai weather in August.
September typically experiences warmer temperatures with a minimum of 24°C (75°F) and an average of 28°C (83°F), peaking at 33°C (92°F). This month also sees significant rainfall, averaging 256 mm (10.1 in) over 21 days, coupled with high humidity at 78%. In contrast, October brings a cooler climate with a minimum temperature of 18°C (65°F) and an average of 25°C (77°F), reaching a maximum of 32°C (90°F). The month also features less rainfall, with 206 mm (8.1 in) occurring over just 14 days, and a slight decrease in humidity to 72%. For more detailed information, you can check Mong Cai weather in October.
September and November showcase a striking contrast in weather. In September, temperatures remain warm, with minimums averaging around 24°C (75°F) and highs reaching up to 33°C (92°F). The month experiences significant rainfall, totaling 256 mm (10.1 in) over 21 days, contributing to a high humidity level of 78%. In contrast, November brings a cooler climate, with temperatures dropping to a minimum of 12°C (54°F) and an average of 22°C (71°F), peaking at 28°C (82°F). Rainfall drastically decreases to 47 mm (1.8 in) over just 8 days, and humidity also lowers to 69%. For more details on the weather in this month, you can explore Mong Cai weather in November.
In September, the weather is characterized by warm temperatures, with daily averages around 28°C (83°F) and highs reaching up to 33°C (92°F). The humidity is relatively high at 78%, accompanied by significant rainfall of 256 mm (10.1 in) spread over 21 days, making it a rather wet month. In contrast, December brings a substantial drop in temperatures, with daily averages declining to 17°C (63°F) and maximums of 25°C (78°F). Precipitation is also much lower, with only 55 mm (2.2 in) over about 10 days, and humidity decreases to 70%. For more detailed information, you can check Mong Cai weather in December.
As September unfolds in Mong Cai, the weather presents a notable shift compared to the preceding months. With temperatures averaging a comfortable 28°C, this month brings a refreshing coolness, especially in contrast to the summer heat. However, it also welcomes significant rainfall, accumulating around 256 mm over 21 days, fostering a lush, vibrant environment. The humidity can feel quite palpable as it hovers around 78%, adding to the tropical allure of the region. This combination of warmth and wetness makes September a unique time to experience the beauty of Mong Cai. For a more detailed insight on this enchanting climate, visit Mong Cai Climate.