Last updated: August 28, 2025
In September, Lao Cai, Vietnam experiences a warm and humid climate, with temperatures peaking at a maximum of 34°C (93°F) and averaging around 25°C (77°F). The weather cools down to a minimum of 18°C (64°F) during the evenings, providing a pleasant respite from the day's heat. With an impressive 193 mm (7.6 in) of rainfall spread across 20 days, the month is characterized by frequent showers, contributing to the lush, scenic beauty of the region. Humidity levels hover around 81%, creating a tropical atmosphere that is both vibrant and refreshing. Travelers to Lao Cai in September should be prepared for the warmth and occasional rain, making it a dynamic time to experience the area's natural allure.
September in Lao Cai, Vietnam brings a gentle transition as summer winds down, with temperatures featuring a pleasant average of 25°C (77°F). As the month progresses, early mornings start off cool with lows around 18°C (64°F), while daytime highs reach a comfortable 34°C (93°F), making it ideal for outdoor explorations. This month marks a noticeable drop from the sweltering summer heat, represented by the consistent temperatures in July and August, which hovered around 35°C (96°F). Consequently, visitors can enjoy the fresh, crisp air and vibrant landscapes, perfect for trekking through this picturesque region while reaping the benefits of milder weather.
In September, Lao Cai experiences significant rainfall, with an average precipitation of 193 mm (7.6 in) spread over approximately 20 days. This marks a slight decline from the record-breaking 313 mm (12.3 in) in August, yet it still contributes to the overall rainy season characterized by substantial moisture. The month transitions gradually towards drier conditions, as hinted by the rising levels noted in October. Interestingly, after the intense summer months where precipitation peaked, September often serves as a bridge, maintaining ample rainfall while hinting at the approaching cooler, drier months ahead. This pattern illustrates the region's dynamic climate, showcasing Lao Cai's lush landscapes shaped by its seasonal rains.
In Lao Cai, Vietnam, September marks a notable transition in humidity levels, with 81% relative humidity. This month follows the peak of the wet season, where July and August recorded a staggering 90% humidity, creating an oppressively humid atmosphere. As we move from the monsoon months, the humidity begins to taper off, offering slight relief while still remaining significantly higher than the drier months earlier in the year. From the dry season's average of 53% in April, the climb to September's levels reflects the region's lush, tropical climate, paving the way for vibrant landscapes. Despite this notable decrease from summer's highs, September retains a notable stickiness that reminds visitors of the enchanting, yet humid, charm of Lao Cai's late summer.
In September, Lao Cai experiences an UV Index of 13, maintaining its status within the extreme exposure category. The burn time drops to a swift 10 minutes, reminding residents and visitors alike to take necessary precautions against harmful UV rays. This month continues a trend observed since March, where the UV Index has remained notably high, fluctuating between 12 and 14 throughout the summer. As the year progresses into autumn, the UV levels begin to gradually decrease, yet the intensity remains significant compared to earlier months. It's essential to stay vigilant and protect your skin during this time. For more detailed insights, check out the comprehensive guide on the Lao Cai UV Index.
UV Risk Categories
As September unfolds in Lao Cai, Vietnam, the region enjoys an impressive 288 hours of sunshine, continuing a trend of abundant sunlight that has characterized the summer months. This peak in bright days follows a vibrant sequence, rising from 173 hours in January to a luminous 313 hours in May, showcasing a consistent increase as the year progresses. The warmth of summer yields to the gentle transition of autumn, with September maintaining high sunlight levels, only slightly lower than the sunnier summer months of June through August. This trend highlights the region's ideal climate for outdoor exploration and scenic adventures, as the days grow shorter yet still bathed in radiant sunlight, making it a perfect time to experience the beauty of Lao Cai.
September in Lao Cai, Vietnam, offers a refreshing respite from the summer months, with a notable 37% chance of sunny weather. This marks an increase from the notably lower percentages experienced during the peak rainy season in June (14%) and July (15%). Interestingly, September's sunny potential is on par with May's 37%, suggesting a favorable transition into autumn. As the year progresses, the likelihood of sunny days tends to taper off into the cooler months, making September a prime opportunity for outdoor adventures and exploration in this picturesque region.
In September, Lao Cai, Vietnam, enjoys a balanced 12 hours of daylight, maintaining the same light as in the previous month, August. This consistency marks a transition from the longer days of summer, peaking at 13 hours in May, June, and July. As the year progresses into October, daylight begins to taper off again, following a gentle decline from the extended hours of spring and summer. The trend of gradually shortening days reflects the rhythmic change in seasons, inviting both locals and travelers to savor the abundant daylight offered in early autumn before the days shorten further into the cooler months ahead.
As September settles in Lao Cai, the wind seems to whisper a gentle lullaby, with an average speed of 1.0 m/s (2 mph), making it the calmest month of the year for breezes. This subtle shift follows a slow decline that began in June, where the winds began their retreat towards tranquility, echoing the warmer days of summer. Despite this newfound stillness, the consistent 1.0 m/s reflects a serenity that characterizes the transition from the bustling heat of summer to the crispness of autumn. As October approaches, the winds are anticipated to pick up slightly, hinting at the return of refreshingly brisk gusts, yet September’s gentle air invites a peaceful pause in the vibrant landscapes of Lao Cai.
Weather in Lao Cai varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Lao Cai, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly different weather conditions. In September, temperatures range from a minimum of 18°C (64°F) to a maximum of 34°C (93°F), with an average of 25°C (77°F). This month sees significant rainfall, totaling 193 mm (7.6 in) across 20 days and high humidity levels at 81%. In contrast, January experiences much cooler temperatures, with a minimum of 4°C (39°F), averaging 15°C (59°F), and peaking at 26°C (78°F). The precipitation decreases to 109 mm (4.3 in) over 18 days, accompanied by lower humidity at 57%. To explore more about the January weather specifics, visit Lao Cai weather in January.
September and February showcase distinct weather patterns. In September, temperatures are noticeably warmer, with minimums around 18°C (64°F) and averages reaching up to 25°C (77°F), peaking at a high of 34°C (93°F). This month also experiences significant rainfall, with 193 mm (7.6 in) over about 20 days, and high humidity levels at 81%. In contrast, February brings cooler and milder conditions, with minimum temperatures dropping to 6°C (42°F) and an average of 16°C (60°F), peaking at 31°C (87°F). February sees less precipitation, totaling 105 mm (4.1 in) across 18 days, along with reduced humidity at 67%. For a detailed look at February weather, check out Lao Cai weather in February.
In September, the weather tends to be hotter and more humid, with average temperatures reaching 25°C (77°F) and maximums peaking at 34°C (93°F). The month experiences significant rainfall, totaling 193 mm (7.6 in) over approximately 20 days, resulting in an average humidity of 81%. In contrast, March offers cooler temperatures, averaging around 19°C (67°F), with a minimum of 11°C (52°F) and maximums slightly lower at 33°C (91°F). Although March has slightly less rainfall at 167 mm (6.6 in) and more rainy days (23), the overall humidity is considerably lower at 58%. For more specific details about climate in March, you can visit Lao Cai weather in March.
When comparing the weather in September and April, we see notable differences in temperature and humidity. September tends to be warmer overall, with average temperatures ranging from a minimum of 18°C (64°F) to a maximum of 34°C (93°F), while April has cooler temperatures, featuring a minimum of 11°C (52°F) and an average high of 36°C (98°F). Both months experience considerable precipitation, with September receiving 193 mm (7.6 in) over 20 days and April recording 195 mm (7.7 in) across 19 days. However, humidity levels are significantly higher in September at 81%, compared to a much drier 53% in April. For more details on the specific conditions in April, you can visit Lao Cai weather in April.
In comparing the weather of September and May, we see some notable differences despite their similar average temperatures of 25°C (77°F). September experiences a slightly higher minimum temperature of 18°C (64°F) compared to May's 15°C (60°F) but has a lower maximum temperature of 34°C (93°F) versus May's peak of 37°C (99°F). Precipitation is more significant in September, with 193 mm (7.6 in) over 20 days, whereas May sees 160 mm (6.3 in) spread across 19 days. Humidity is also higher in September at 81% compared to May's 69%, making September feel a bit more muggy. For a closer look at the conditions in May, check out Lao Cai weather in May.
When comparing the weather in September and June, both months exhibit warm temperatures and high humidity levels, but there are some notable differences. In June, the temperatures range from a minimum of 20°C (68°F) to a maximum of 36°C (97°F), with an average of 27°C (81°F). This month sees slightly more precipitation at 202 mm (7.9 in) over 20 days, resulting in a humidity level of 83%. Conversely, September presents a slightly cooler climate with minimum temperatures of 18°C (64°F) and maximums reaching 34°C (93°F), averaging 25°C (77°F). The precipitation for September is 193 mm (7.6 in), also spread across 20 days, and has a humidity level of 81%. For more insights on the climate during this period, check Lao Cai weather in June.
When comparing the weather in September and July, notable differences in temperature, precipitation, and humidity emerge. In July, temperatures are generally warmer, with a minimum of 22°C (72°F), an average of 26°C (80°F), and a maximum of 35°C (96°F). This month also experiences higher humidity at 90% and more precipitation, totaling 225 mm (8.8 in) over 24 days. In contrast, September has a slightly cooler climate with a minimum temperature of 18°C (64°F), an average of 25°C (77°F), and a maximum of 34°C (93°F). Although September is somewhat less humid at 81%, it still sees significant rainfall with 193 mm (7.6 in) spread across 20 days. For a detailed look at the weather in July, you can visit Lao Cai weather in July.
In comparing the weather between September and August, September experiences slightly cooler temperatures, with a minimum of 18°C (64°F) and an average of 25°C (77°F), whereas August boasts a minimum of 21°C (71°F) and an average of 26°C (80°F). Although September has a max temperature of 34°C (93°F), August reaches higher with a maximum of 35°C (96°F). Precipitation is significantly lower in September, totaling 193 mm (7.6 in) over 20 days, compared to August's 313 mm (12.3 in) over 22 days. Additionally, humidity levels in September are a bit lower at 81%, compared to August's higher 90%. For more detailed insights, you can check Lao Cai weather in August.
September and October exhibit noticeable changes in weather patterns. In September, temperatures range from a mild 18°C (64°F) to a hot 34°C (93°F), with an average of 25°C (77°F). The month is characterized by high humidity at 81% and substantial rainfall, totaling 193 mm (7.6 in) over 20 days. In contrast, October sees cooler temperatures, with a minimum of 14°C (57°F) and a maximum of 31°C (88°F), yielding an average temperature of 22°C (72°F). While precipitation increases to 217 mm (8.6 in) over 22 days, humidity drops to 75%. For more details on the weather in October, check out Lao Cai weather in October.
September experiences warmer temperatures, with minimums around 18°C (64°F) and averages peaking at approximately 25°C (77°F), while November sees cooler conditions, dropping to a minimum of 10°C (51°F) and an average of 19°C (66°F). Rainfall is significantly higher in September, with 193 mm (7.6 in) over 20 days, compared to November's 100 mm (3.9 in) over 18 days. Humidity also slightly decreases from September's 81% to November's 74%, making November feel more comfortable despite the cooler temperatures. For more detailed insights, check out Lao Cai weather in November.
In September, the weather is distinctly warmer with average temperatures ranging from a minimum of 18°C (64°F) to a maximum of 34°C (93°F), while December experiences much cooler conditions, with temperatures spanning from a low of 3°C (38°F) to a high of 26°C (80°F). September also sees significantly higher precipitation, totaling 193 mm (7.6 in) over 20 days, compared to December's 97 mm (3.8 in) over 15 days. Additionally, humidity levels are higher in September at 81%, whereas December's humidity drops to 69%. For more details about December weather, you can visit Lao Cai weather in December.
As September unfolds in Lao Cai, the weather showcases a distinct transformation compared to the hotter summer months. With a balanced average temperature that hovers around a comfortable 25°C (77°F), it becomes a refreshing respite from the soaring highs of preceding weeks. However, this month also brings increased precipitation, casting a veil of lush greenery over the landscape, as rain falls on about 20 days, resulting in a notable 193 mm (7.6 in). This combination of warmth and humidity, reaching 81%, makes for a unique atmospheric experience. For more insights into the region's climate variations, explore Lao Cai Climate.