September Weather in Si Mueang Mai, Thailand

Last updated: August 27, 2025

September in Si Mueang Mai, Thailand offers a warm embrace with maximum temperatures reaching 35°C (95°F) and an average of 28°C (82°F). As the monsoon season unfolds, residents and visitors may experience significant rainfall, totaling 334 mm (13.1 in) over approximately 25 days. The lush, tropical landscape flourishes under the persistent drizzle, while humidity levels soar to a steaming 91%. This combination of warmth and wetness creates a vibrant atmosphere, perfect for exploring the rich culture and natural beauty of the region.

September Temperature in Si Mueang Mai

In September, Si Mueang Mai experiences a transitional warmth, with temperatures reflecting the tail end of the monsoon season. The minimum temperature hovers at a comfortable 23°C (73°F), while daily averages settle around 28°C (82°F), making it a pleasant time for outdoor activities. The maximum temperature peaks at 35°C (95°F), similar to the hotter months prior, indicating lingering summer heat. Compared to earlier months, there is a slight reduction in extremes, with both maximum and average temperatures gently declining towards the cooler autumn months. This trend presents a perfect opportunity for visitors to explore the rich culture and stunning landscapes of Thailand without the sweltering heat of peak summer.

September Weather in Si Mueang Mai: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Si Mueang Mai, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Si Mueang Mai, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec777884858484828282817976
Data source: Temperature data for Si Mueang Mai generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Si Mueang Mai

In September, Si Mueang Mai experiences a peak in precipitation, with 334 mm (13.1 in) of rain falling over approximately 25 days. This marks a continuation of the monsoon season, characterized by intense rainfall that begins to ramp up in July and August. Notably, September's precipitation is slightly higher than that of the preceding months, highlighting a consistent upward trend in rainfall as the year progresses. This month often sees lush landscapes and a vibrant atmosphere as the region welcomes the nourishing rains, vital for agriculture and local ecosystems. As October approaches, the precipitation begins to taper off, signaling the transition into a drier period.

September Precipitation Trends in Si Mueang Mai

The chart displays monthly precipitation patterns in Si Mueang Mai, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Si Mueang Mai, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec482974160197324321334193456
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Si Mueang Mai

In September, Si Mueang Mai, Thailand, experiences a notable decline in humidity compared to the preceding months of peak moisture, with levels settling at 91%. This slight decrease from the sweltering 93% recorded in August marks the end of the region's most humid period, which typically spans from June to August. Following the heat of summer, the humidity begins a slow descent, paving the way for the transition into the cooler months. With levels remaining high into October at 88%, the September climate continues to offer that characteristic tropical mugginess, but hints at a gradual relief for residents and visitors alike, as the region prepares for the dryer, cooler air of autumn.

September Average Humidity in Si Mueang Mai

This chart illustrates the average monthly humidity levels in Si Mueang Mai, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Si Mueang Mai is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec74%65%53%49%73%86%91%93%91%88%85%82%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Si Mueang Mai

In September, Si Mueang Mai, Thailand, continues to experience extreme UV levels, with a UV Index of 14 and a quick burn time of just 10 minutes. This trend of high UV intensity is consistent throughout the summer months, peaking in May and July at a particularly intense 15. As the rainy season approaches, although the UV Index dips slightly in October, it remains notably high, marking a prevalent pattern of extreme exposure from February through September. Awareness of these conditions is crucial for locals and visitors alike to protect their skin. Plan your outdoor activities with caution and stay informed by checking the latest updates on the Si Mueang Mai UV Index.

Maximum UV Index Levels in Si Mueang Mai for September

The chart shows the monthly maximum UV Index (UVI) for Si Mueang Mai in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Si Mueang Mai typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec10131414151315141412109
Data source: Si Mueang Mai September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Si Mueang Mai

As September unfolds in Si Mueang Mai, Thailand, the sun shines for 273 hours, marking a slight dip from the vibrant summer months yet still basking in a generous amount of daylight. This month serves as a transition, bridging the end of the rainy season and the burgeoning coolness of autumn. While hours of sunshine decrease compared to the peak of spring, when March dazzles with 324 hours of sunshine, September's brightness maintains a warm glow, more than enough to entice visitors and locals alike. The gradual decline in daylight hours begins to set the stage for the crispness of October, which enjoys 281 hours of sun, hinting at the seasonal shifts that will soon envelop this enchanting region.

Monthly Sunshine Duration in Si Mueang Mai: September Highlighted

The September sunshine duration represents the total number of hours Si Mueang Mai experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec261h298h324h314h318h300h270h256h273h281h296h314h
Data source: Si Mueang Mai September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Si Mueang Mai During September

In Si Mueang Mai, Thailand, September marks a notable dip in the likelihood of sunny weather, with only a 14% chance of encountering clear skies. This trend is part of a broader pattern through the monsoon season, where the chances of sunshine plummet from the preceding months; for comparison, June and July see just 21% and 15% likelihoods, respectively. After a relatively bright start to the year, with February shining at an impressive 83%, the drop in sunlit days through the summer into September suggests it's time to prepare for rain rather than rays. As October approaches, there is a slight uptick in sun chances to 18%, but for those seeking sunny escapades, September’s overcast skies may necessitate a shift in travel plans.

Percentage of Sunny Days in September in Si Mueang Mai

The chart illustrates the percentage of sunny days in Si Mueang Mai throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Si Mueang Mai experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec74%83%66%36%39%21%15%11%14%18%46%56%
Data source: Si Mueang Mai September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Si Mueang Mai in September

In Si Mueang Mai, Thailand, September experiences a consistent 12 hours of daylight, mirroring the preceding months of April, May, July, and August. This stability reflects a gentle transition as the region shifts from the longer days of late summer into the shorter days of autumn. Interestingly, the daylight duration peaks in June with 13 hours, creating a bright backdrop for outdoor activities during the peak of the rainy season. As autumn approaches, October brings a slight decrease in daylight to 11 hours, hinting at the natural cycle of change ahead. Overall, September’s equal split of day and night exemplifies the region's pleasant climate, making it an ideal time for exploration and enjoyment.

Average Daylight Hours in Si Mueang Mai for September

The chart illustrates the variation in daylight duration in Si Mueang Mai throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 18m11h 37m12h 2m12h 28m12h 50m13h 1m12h 55m12h 36m12h 11m11h 45m11h 23m11h 12m
Data source: Si Mueang Mai daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Si Mueang Mai

In September, Si Mueang Mai, Thailand, experiences a gentle breeze with an average wind speed of 1.8 m/s (4 mph), making it one of the calmest months of the year. This lull follows a gradual decrease in wind speeds during the pre-monsoon summer months, reaching their lowest point just as the rainy season begins to settle in. The tranquility of September is contrasted with the more vigorous winds of January and November, both boasting averages of 4.2 m/s (9 mph) or higher. As the seasons shift, wind speeds will start to rise again in October, hinting at the dynamic climatic patterns that characterize this vibrant region. Overall, September’s subdued breezes offer a serene escape, ideal for immersing oneself in the lush landscapes and cultural richness of northern Thailand.

Average September Wind Speed in Si Mueang Mai

The chart displays monthly wind speed patterns in Si Mueang Mai, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.22.92.31.91.92.92.72.51.8 m/s2.84.24.8
Data source: Si Mueang Mai September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Si Mueang Mai Compares to Other Months

Weather in Si Mueang Mai varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Si Mueang Mai, focusing on differences in temperature, rainfall, humidity, and UV levels.

September and January present stark contrasts in weather. In September, temperatures range from a minimum of 23°C (73°F) to a maximum of 35°C (95°F), averaging 28°C (82°F). The month is also characterized by high humidity at 91% and significant precipitation, with 334 mm (13.1 in) falling over 25 days. In contrast, January features a cooler climate, with minimum temperatures dropping to 12°C (53°F) and an average of 25°C (77°F), reaching similar highs of 35°C (96°F) on warmer days. Precipitation is minimal in January, with only 4 mm (0.2 in) over just 1 day, and humidity levels decrease to 74%. For more detailed insights into the weather in January, you can visit Si Mueang Mai weather in January.

September and February present contrasting weather patterns. In September, temperatures range from a minimum of 23°C (73°F) to a maximum of 35°C (95°F), with an average of 28°C (82°F). This month is characterized by high humidity at 91% and significant rainfall, totaling 334 mm (13.1 in) over 25 days. In stark contrast, February experiences milder temperatures, with a minimum of 13°C (56°F) and a maximum of 37°C (98°F), averaging 26°C (79°F). Rainfall is minimal during this month, with only 8 mm (0.3 in) occurring on just 1 day, and the humidity drops to a comfortable 65%. For more detailed information, visit Si Mueang Mai weather in February.

When comparing the weather in September and March, there are notable differences in temperature and humidity. September typically sees higher humidity at 91%, with average temperatures ranging from a minimum of 23°C (73°F) to a maximum of 35°C (95°F) and significant rainfall of 334 mm (13.1 in) over 25 days. In contrast, March offers warmer temperatures, with averages from a minimum of 17°C (63°F) to a peak of 39°C (102°F), but is much drier, receiving only 29 mm (1.1 in) of rain over just 6 days and a lower humidity level of 53%. For a closer look at the weather specifics in March, you can visit Si Mueang Mai weather in March.

When comparing the weather in September and April, notable differences emerge. September experiences a warmer average temperature of 28°C (82°F) with maximum highs reaching up to 35°C (95°F), while April boasts an even higher maximum of 40°C (103°F), despite having a similar average of 29°C (85°F). However, September is characterized by significantly higher precipitation, with 334 mm (13.1 in) falling over 25 days, leading to a humid environment with 91% humidity. In contrast, April has a much drier climate, with only 74 mm (2.9 in) of rain over 12 days and considerably lower humidity at 49%. For more detailed information, you can check Si Mueang Mai weather in April.

When comparing the weather in September and May, September tends to be warmer and more humid. September features minimum temperatures around 23°C (73°F) and averages 28°C (82°F), peaking at 35°C (95°F). The month is characterized by high humidity at 91% and significant precipitation, with 334 mm (13.1 in) falling over 25 days. In contrast, May starts off with slightly cooler minimum temperatures of 20°C (67°F) and an average of 29°C (85°F), reaching a maximum of 40°C (104°F). While May still experiences some rainfall, totaling 160 mm (6.3 in) over 21 days, the humidity is notably lower at 72%, making it feel less oppressive compared to September. For more detailed insights into the weather conditions, check Si Mueang Mai weather in May.

When comparing the weather in September to that of June, we notice some distinct differences. In September, temperatures range from a minimum of 23°C (73°F) to a maximum of 35°C (95°F), with an average temperature of 28°C (82°F). This month also experiences significant rainfall, totaling 334 mm (13.1 in) over 25 days, contributing to a higher humidity level of 91%. In contrast, June sees slightly warmer temperatures, with a minimum of 24°C (75°F) and a maximum of 36°C (97°F), averaging 29°C (84°F). However, June has less rainfall, with 197 mm (7.8 in) over 24 days, resulting in a lower humidity of 86%. For more detailed insights, refer to Si Mueang Mai weather in June.

In both September and July, the weather displays similar temperature patterns, with minimums around 23°C (73°F), averages of 28°C (82°F), and maximums reaching 35°C (95°F). However, September experiences slightly more precipitation, totaling 334 mm (13.1 in) over 25 rainy days, compared to July's 324 mm (12.8 in) spread across 27 days. This indicates that while both months are quite humid at 91%, September tends to be wetter, which can impact outdoor activities. For a closer look at July weather specifics, you can check out Si Mueang Mai weather in July.

In comparing the weather of September to August, both months exhibit similar temperature ranges, with September featuring a minimum of 23°C (73°F), an average of 28°C (82°F), and a maximum of 35°C (95°F). In August, the temperatures are slightly lower, with a maximum of 34°C (94°F). Notably, September experiences slightly more rainfall, totaling 334 mm (13.1 in) over 25 days compared to August's 321 mm (12.6 in) across 29 days. Additionally, humidity levels are marginally lower in September at 91%, compared to 93% in August. For more information on weather conditions during August, you can check Si Mueang Mai weather in August.

In September, temperatures remain warm with a minimum of 23°C (73°F) and an average of 28°C (82°F), peaking at a maximum of 35°C (95°F). However, this month is characterized by heavy rainfall, totaling 334 mm (13.1 in) over 25 days, and high humidity levels averaging 91%. In contrast, October shows a slight drop in temperature, with minimums at 20°C (68°F) and an average of 27°C (81°F), while still reaching a maximum of 35°C (95°F). Rainfall decreases significantly to 193 mm (7.6 in) over 17 days, contributing to somewhat lower humidity at 88%. For more detailed weather information, check out Si Mueang Mai weather in October.

In comparing the weather between September and November, September displays a warmer and wetter climate. Average temperatures in September range from a minimum of 23°C (73°F) to a maximum of 35°C (95°F), while November experiences slightly cooler conditions with temperatures ranging from a minimum of 18°C (66°F) to a maximum of 35°C (96°F). Moreover, September receives significantly higher precipitation, totaling 334 mm (13.1 in) over 25 days, compared to November's modest 45 mm (1.8 in) across just 5 days. Humidity levels also differ slightly, with September boasting a higher humidity of 91%, while November sits at 85%. For a more detailed look at November's conditions, you can visit Si Mueang Mai weather in November.

In September, the weather is markedly warmer and more humid, with temperatures ranging from a minimum of 23°C (73°F) to a maximum of 35°C (95°F) and an average of 28°C (82°F). This month experiences significant rainfall, with precipitation totaling 334 mm (13.1 in) over approximately 25 days, leading to a humidity level of 91%. In contrast, December presents a cooler and drier climate, with temperatures ranging from a minimum of 14°C (57°F) to a maximum of 34°C (94°F) and an average of 24°C (76°F). Precipitation is minimal during this month, with only 6 mm (0.2 in) recorded over just 1 day, resulting in lower humidity levels at 82%. For those interested in more details, visit Si Mueang Mai weather in December.

Compare Si Mueang Mai's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Si Mueang Mai

In September, Si Mueang Mai experiences a notable shift in weather, characterized by warm temperatures and high humidity levels that create a tropical atmosphere. As the region endures frequent rainfall, typically over twenty-five days of precipitation, the landscape flourishes into vibrant hues of green, contrasting with the drier months preceding it. This month’s average temperature hovers around a balmy 28°C, making it one of the warmest yet wettest periods of the year. The heavy rain enriches the air, bringing a refreshing coolness that provides relief at the end of hot days, distinguishing September’s climate from the surrounding months. For more insights on how weather patterns evolve throughout the year, explore Si Mueang Mai Climate.