September Weather in Ratchaburi, Thailand

Last updated: August 27, 2025

In September, Ratchaburi, Thailand experiences a tropical climate marked by high temperatures and considerable precipitation. The month sees a maximum temperature soaring to 37°C (100°F), while the average hovers around 29°C (84°F), and nights cool down to around 24°C (76°F). With humidity levels reaching 87%, the air feels particularly muggy. Rain is a frequent visitor, with 209 mm (8.2 in) of precipitation spread over 24 days, transforming the landscape and offering a lush green backdrop to the vibrant local scenery.

September Temperature in Ratchaburi

In September, Ratchaburi, Thailand, experiences a warm embrace of temperatures, with minimums hovering around 24°C (76°F) and averages steady at 29°C (84°F). The mercury can peak at 37°C (100°F), keeping the month in line with the preceding hot summer months. This consistency in warmth marks September as a transitional period, where the lingering heat of late summer begins to gradually soften as the region approaches the cooler months of October and November. Notably, the temperatures this month closely mirror those of August, suggesting that the tropical climate remains steadfast before the onset of the slightly cooler autumn. Travelers should prepare for balmy days, making September a vibrant time to explore the lush landscapes of Ratchaburi.

September Weather in Ratchaburi: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Ratchaburi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ratchaburi, 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).
JanFebMarAprMayJunJulAugSepOctNovDec798185878685848483828179
Data source: Temperature data for Ratchaburi 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 Ratchaburi

September marks a significant peak in precipitation for Ratchaburi, Thailand, as the region receives 209 mm (8.2 in) of rain over 24 days. This intense rainfall follows a progressive buildup throughout the monsoon season, starting from a modest 21 mm in January and escalating to a striking 167 mm in August. The trend illustrates how the rainy season reaches its zenith in September, reflecting the region's reliance on monsoonal patterns for water resources. This deluge not only nourishes the lush landscapes but also sets the stage for a gentle decline in precipitation as the year draws to a close, with October following closely behind at 202 mm.

September Precipitation Trends in Ratchaburi

The chart displays monthly precipitation patterns in Ratchaburi, 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 Ratchaburi, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec211230881411251201672092028317
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Ratchaburi

In September, Ratchaburi, Thailand experiences a notable humidity level of 87%, which marks a slight decrease from the peak humidity of 90% observed in August. This month is part of a trend where humidity steadily rises from a moderate 58% in January to a summer high in the earlier months, reaching 89% by July. As the region transitions into October, there’s a gradual dip, signaling the approach of drier months. Overall, September is characterized by a lingering moisture that reflects the city's tropical climate, while hinting at the impending relief of lower humidity in the months to follow.

September Average Humidity in Ratchaburi

This chart illustrates the average monthly humidity levels in Ratchaburi, 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 Ratchaburi is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec58%59%62%69%79%87%89%90%87%83%77%66%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Ratchaburi

In September, Ratchaburi, Thailand, continues to experience extreme UV levels, with an average UV Index of 13 and a consistent burn time of just 10 minutes. This trend reflects the intense solar exposure that characterizes much of the year, particularly from March to August, when the UV Index reached as high as 14. As the transition to October occurs, the UV Index remains steadfast at 13, suggesting that sun safety measures are still critical during this month. With such high UV ratings throughout much of the year, residents and visitors alike should remain vigilant about sun protection. For more detailed information on the UV Index in Ratchaburi, visit Ratchaburi UV Index.

Maximum UV Index Levels in Ratchaburi for September

The chart shows the monthly maximum UV Index (UVI) for Ratchaburi 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 Ratchaburi typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec11121414141314141313109
Data source: Ratchaburi 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 Ratchaburi

In September, Ratchaburi, Thailand, basks in approximately 260 hours of sunshine, marking a slight dip compared to the preceding months. This decline follows the region's vibrant peak in March with an impressive 333 hours, creating a noticeable transition as the rainy season approaches. While July and August showcase a gradual decrease in sunlight, September continues this trend, hinting at the upcoming rainy months. Nonetheless, the sunlight remains abundant enough to enjoy outdoor activities, offering a perfect balance between warmth and the refreshing onset of the monsoon. As autumn begins, Ratchaburi's enchanting landscapes thrive under a canopy of golden rays, making September a delightful time to explore the region's natural beauty.

Monthly Sunshine Duration in Ratchaburi: September Highlighted

The September sunshine duration represents the total number of hours Ratchaburi 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.
JanFebMarAprMayJunJulAugSepOctNovDec251h299h333h319h317h300h280h267h260h283h293h315h
Data source: Ratchaburi September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Ratchaburi During September

September in Ratchaburi, Thailand, sees a marked decline in sunny weather, with just an 8% chance of sunshine. This trend aligns with the region's rainy season, which typically peaks during the monsoon months of July and August, resulting in consistently low sun exposure. Following this pattern, the likelihood of sunny days gradually begins to rise again in October, reaching 14%, suggesting that while September may be dreary, the promise of clearer skies is just around the corner. So, if you're planning a visit, be prepared for overcast skies and occasional rain, as the sun remains elusive this time of year.

Percentage of Sunny Days in September in Ratchaburi

The chart illustrates the percentage of sunny days in Ratchaburi 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 Ratchaburi experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec62%77%59%18%31%16%11%8%8%14%26%62%
Data source: Ratchaburi September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Ratchaburi in September

In Ratchaburi, Thailand, September marks a continuation of a steady trend in daylight duration, offering a consistent 12 hours of sunlight each day. This extended daylight period persists from March through September, allowing residents and visitors alike to enjoy vibrant outdoor activities. As the year progresses, the daylight starts to taper off in October, where it drops back to 11 hours, echoing the patterns seen in the initial months of the year. This rhythm of light and dark highlights the region's tropical climate, where prolonged daytime promotes a lively atmosphere, particularly during the lush rainy season leading into autumn.

Average Daylight Hours in Ratchaburi for September

The chart illustrates the variation in daylight duration in Ratchaburi throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 24m11h 41m12h 2m12h 25m12h 44m12h 53m12h 49m12h 32m12h 10m11h 48m11h 29m11h 19m
Data source: Ratchaburi daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Ratchaburi

In September, Ratchaburi, Thailand experiences a subtle decline in wind activity, with an average speed of just 1.5 m/s (3 mph). This marks the lowest wind speed of the year, contrasting sharply with the more breezy months preceding it, where averages hovered around 2.0 to 2.2 m/s (4 to 5 mph). Following the monsoon season, September often brings a sense of tranquility, as the wind calms, creating a serene atmosphere in this vibrant region. As the year progresses into October, a slight uptick in wind speed to 1.7 m/s (4 mph) hints at the return of gentle breezes, sweetening the air as the landscape prepares for the cooler months ahead. Overall, September serves as a mellow transition, where the serene winds reflect the changing seasons in Ratchaburi.

Average September Wind Speed in Ratchaburi

The chart displays monthly wind speed patterns in Ratchaburi, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.12.02.21.61.82.22.22.01.5 m/s1.72.12.4
Data source: Ratchaburi September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Ratchaburi Compares to Other Months

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

September and January present contrasting weather patterns. In September, temperatures range from a minimum of 24°C (76°F) to a maximum of 37°C (100°F), with an average of 29°C (84°F). This month is characterized by high humidity at 87% and a significant amount of rainfall, totaling 209 mm (8.2 in) over 24 days. In stark contrast, January experiences milder weather with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 34°C (94°F), averaging 26°C (80°F). Rainfall is minimal in January, with only 21 mm (0.8 in) over 3 days and a lower humidity level of 58%. For more detailed information on January weather, you can refer to Ratchaburi weather in January.

September and February present contrasting weather conditions. In September, temperatures typically range from a minimum of 24°C (76°F) to a maximum of 37°C (100°F), with an average of 29°C (84°F). This month is characterized by high humidity at 87% and significant rainfall, with precipitation recorded on 24 days totaling 209 mm (8.2 inches). In contrast, February experiences milder temperatures, with a minimum of 19°C (67°F) and a maximum of 36°C (97°F), averaging 27°C (82°F). The humidity drops notably to 59%, and rainfall is scarce, with only 12 mm (0.5 inches) falling over just 2 days. For more detailed information about February weather, you can check Ratchaburi weather in February.

In comparing the weather of September and March, one can observe notable differences. September experiences higher humidity at 87% and a substantial amount of rainfall, with a total of 209 mm spread over 24 days, making it one of the wettest months. The temperatures range from a minimum of 24°C (76°F) to a maximum of 37°C (100°F), resulting in an average of 29°C (84°F). In contrast, March boasts a drier climate, with only 30 mm of precipitation over 4 days and significantly lower humidity at 62%. The temperature range is similar, with a minimum of 21°C (70°F) and a maximum of 38°C (102°F), yielding an average of 30°C (86°F). For more specific weather information in March, you can check Ratchaburi weather in March.

When comparing the weather in September and April, a few notable differences emerge. September typically experiences a higher average humidity of 87%, paired with a significant amount of rainfall, totaling 209 mm over approximately 24 days. In contrast, April tends to be drier with only 88 mm of precipitation over 11 days and a lower humidity level of 69%. Temperature-wise, while both months can feel quite warm, April sees higher maximum temperatures reaching up to 40°C (104°F), compared to September’s maximum of 37°C (100°F). For more specifics on April weather, you can check this link: Ratchaburi weather in April.

When comparing the weather in September and May, both months share a warm minimum temperature of around 24°C (75-76°F). However, May typically has a higher average temperature of 30°C (87°F) compared to September's 29°C (84°F), with May reaching a maximum of 40°C (105°F), which is notably warmer than September's peak of 37°C (100°F). Precipitation levels also differ, with September receiving more rain at 209 mm (8.2 in) over 24 days, while May experiences less, totaling 141 mm (5.5 in) over 20 days. Furthermore, September's humidity is higher at 87% compared to May's 79%. To explore more about May weather in Ratchaburi, you can check Ratchaburi weather in May.

In comparing the weather of September and June, we observe some notable similarities and differences. September has slightly lower average temperatures, with a minimum of 24°C (76°F) and an average of 29°C (84°F), compared to June's minimum of 25°C (77°F) and average of 30°C (85°F). Both months can reach high temperatures, with June peaking at 38°C (100°F) and September also maxing out at 37°C (100°F). However, September experiences significantly more precipitation, receiving 209 mm (8.2 in) over 24 days, while June sees 125 mm (4.9 in) over 21 days. Both months maintain high humidity levels of 87%, contributing to the overall tropical feel. For more detailed information, you can check out Ratchaburi weather in June.

In comparing the weather between September and July, we see some notable similarities and differences. Both months experience high average temperatures around 29°C (85°F), yet September has slightly cooler minimum temperatures at 24°C (76°F) compared to 25°C (77°F) in July. However, July tends to have marginally less precipitation, with 120 mm (4.7 in) falling over 22 days, while September sees a significant increase in rainfall at 209 mm (8.2 in) over 24 days, contributing to a more humid environment with 87% humidity in September versus 89% in July. For a more detailed look at Ratchaburi's weather during July, you can visit Ratchaburi weather in July.

In comparing the weather conditions of September to August, both months share similar temperature ranges, with minimums at 24°C (76°F) and averages around 29°C (84°F). However, September experiences a slight increase in maximum temperatures reaching up to 37°C (100°F), compared to August’s 37°C (99°F). Precipitation is notably higher in September, with 209 mm (8.2 in) over 24 days, compared to August's 167 mm (6.6 in) across 25 days. Humidity levels also shift slightly, with September sitting at 87% compared to August’s 90%. Overall, September tends to be wetter but slightly less humid than August. For more specifics, you can check out Ratchaburi weather in August.

In September, temperatures in Ratchaburi typically range from a minimum of 24°C (76°F) to a maximum of 37°C (100°F), with an average temperature of 29°C (84°F). The month is characterized by substantial rainfall, accumulating 209 mm (8.2 in) over 24 days, and humidity levels are quite high at 87%. In contrast, October sees slightly cooler temperatures, with a minimum of 23°C (73°F), an average of 28°C (83°F), and a maximum of 35°C (95°F). Precipitation decreases marginally to 202 mm (7.9 in) over 21 days, and humidity also drops to a more comfortable 83%. For more details on weather patterns, you can check out Ratchaburi weather in October.

In comparing the weather patterns of September and November, September is characterized by higher temperatures and more humidity, with a minimum of 24°C (76°F) and an average of 29°C (84°F), peaking at a scorching 37°C (100°F). The month also sees significant rainfall, with 209 mm (8.2 in) distributed over 24 days, contributing to a humidity level of 87%. In contrast, November experiences milder conditions, with a minimum temperature of 21°C (70°F) and an average of 27°C (81°F), reaching a maximum of 34°C (93°F). Rainfall decreases substantially in November to 83 mm (3.3 in) over just 10 days, leading to a more comfortable humidity level of 77%. For more detailed insights on November weather patterns, check out Ratchaburi weather in November.

In September, the weather is significantly warmer and more humid, with average temperatures ranging from a minimum of 24°C (76°F) to a maximum of 37°C (100°F). The month experiences substantial rainfall, totaling 209 mm (8.2 in) over 24 days, leading to a humidity level of 87%. In stark contrast, December sees much cooler and drier conditions, with temperatures ranging from a minimum of 16°C (61°F) to a maximum of 35°C (95°F). Rainfall drops dramatically to just 17 mm (0.7 in) over only 3 days, and humidity decreases to 66%. For more detailed information, you can check Ratchaburi weather in December.

Compare Ratchaburi's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Ratchaburi

As September rolls around in Ratchaburi, the weather transforms into a moist and humid experience, contrasting sharply with the drier months that precede it. With an average temperature hovering around a warm 29°C, the days can feel quite steamy, especially with a high humidity level of 87%. Rainfall becomes a frequent visitor, gracing the region with approximately 24 rainy days and bringing a substantial 209 mm of precipitation. This shift not only adds a refreshing touch to the landscape but also heralds the lush greenery that follows. For a deeper dive into the weather patterns throughout the year, visit Ratchaburi Climate.