September Weather in Suwon, South Korea

Last updated: October 30, 2025

September in Suwon, South Korea is characterized by a delightful blend of warmth and moisture, with average temperatures hovering around 22°C (71°F). The month can peak at a balmy 31°C (88°F), making it ideal for outdoor exploration, while nights may cool down to a refreshing low of 9°C (48°F). Rain is a frequent companion during this time, with 136 mm (5.4 in) of precipitation spread over 9 days, contributing to a humidity level of 77%, which adds a lush ambiance to the scenery. Visitors can expect a vibrant atmosphere filled with both sunshine and occasional showers, perfect for experiencing the charm of Suwon.

September Temperature in Suwon

As September unfolds in Suwon, South Korea, the city transitions into a delightful autumn atmosphere. The temperatures begin to cool, with minimums dropping to around 9°C (48°F), providing a refreshing respite from the sweltering summer heat. Daytime averages hover at a comfortable 22°C (71°F), inviting outdoor explorations through the vibrant foliage. Peaks reach a pleasant 31°C (88°F), allowing for warm afternoons that still encourage people to enjoy the outdoors before the chill of fall sets in. This month marks a significant shift in the climate, setting the stage for cozy sweater weather and picturesque seasonal changes.

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

The chart illustrates September temperature patterns in Suwon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Suwon, September typically has an average temperature of 22°C (71°F), with highs reaching up to 31°C (88°F) and lows dropping to around 9°C (48°F).
JanFebMarAprMayJunJulAugSepOctNovDec293244546472798071594632
Data source: Temperature data for Suwon 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 Suwon

In September, Suwon experiences a notable shift in weather as rainfall peaks during the transition from summer to autumn. With a total precipitation of 136 mm (5.4 in) spread across 9 days, the month sees a substantial drop from the intense summer rains of July and August, which recorded 235 mm and 255 mm, respectively. This marked decrease signals a gradual shift, as September's rainfall is less than half of that from the previous two months, yet it remains significant compared to the drier months that follow. As the season progresses, the skies begin to clear, with October typically bringing just 62 mm (2.5 in) of rain over only 5 days. The varying precipitation patterns highlight the initial lingering effects of summer's moisture before autumn ushers in crisp, drier air.

September Precipitation Trends in Suwon

The chart displays monthly precipitation patterns in Suwon, 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 Suwon, September typically receives around 136 mm (5.4 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec212347549880235256136625426
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Suwon

In September, Suwon experiences a notable shift in humidity, averaging 77%. This marks a decline from the intense high of 91% seen in both July and August, as the summer heat starts to wane. While the humidity remains relatively high compared to the winter months, it reflects a transitional phase where the balmy summer air gradually gives way to cooler autumn breezes. Following September, humidity levels will fluctuate slightly, with October seeing a slight rise to 79%. Overall, the month serves as a bridge between the oppressive dampness of summer and the more moderate conditions that define the later fall season, illustrating the region's evolving climate patterns.

September Average Humidity in Suwon

This chart illustrates the average monthly humidity levels in Suwon, 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 Suwon is approximately 77%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec71%65%65%75%81%85%91%91%77%79%80%74%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Suwon

As September rolls into Suwon, South Korea, residents and visitors alike should prepare for a very high UV Index of 9, indicative of the lingering summer sun. This month follows the intense heat of July and August, both carrying an extreme UV index of 11, but now with a slight reprieve in burn time—only 15 minutes of unprotected sun exposure is enough to cause skin damage. Looking back at the trends from earlier months, there’s a clear escalation in UV levels as the year progresses, peaking during the peak summer months before tapering in October. As always, taking precautions against UV exposure remains essential; for more insights, visit Suwon UV Index.

Maximum UV Index Levels in Suwon for September

The chart shows the monthly maximum UV Index (UVI) for Suwon 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 Suwon typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec346891011119643
Data source: Suwon 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 Suwon

As September unfolds in Suwon, South Korea, residents enjoy an impressive 261 hours of sunshine, making it a delightful transition from the radiant summer months. Following a peak in May and June, where the city basked in 315 and 318 hours respectively, September showcases a gentle decline in sunlight, yet still outshines the earlier months of the year. This trend highlights a favorable stretch of sunny days, continuing the momentum of the summer while hinting at the cooler embrace of autumn. With the sun gradually waning, September offers a golden opportunity to savor the warmth before the shorter days set in, inviting both locals and visitors to revel in the lingering brilliance of the season.

Monthly Sunshine Duration in Suwon: September Highlighted

The September sunshine duration represents the total number of hours Suwon 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.
JanFebMarAprMayJunJulAugSepOctNovDec198h242h283h289h315h318h293h290h261h266h231h235h
Data source: Suwon September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Suwon During September

As September rolls around in Suwon, South Korea, the chance of sunny weather hovers at 39%, which is slightly lower than the summer months of July and August, both known for their high humidity and frequent rain. This pattern suggests that while the oppressive heat of summer begins to wane, a fair amount of cloud cover still lingers, leading to a transitional period before the cooler autumn days set in. Interestingly, September's sunlight probability marks an uptick from the preceding months, hinting at a gradual return to clearer skies. In comparison to the winter months, which feature higher chances of sunshine later in the year, September serves as a bridge, where fleeting warm days can still surprise residents amid the shifting seasons.

Percentage of Sunny Days in September in Suwon

The chart illustrates the percentage of sunny days in Suwon 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 Suwon experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec49%53%43%43%39%40%30%31%39%47%57%63%
Data source: Suwon September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Suwon in September

In Suwon, South Korea, September marks a gentle transition from the long, sun-soaked days of summer to the cooler embrace of autumn. With approximately 12 hours of daylight, this month showcases a gradual decrease from the peak summer months of June to August, where sunlight reached 14 hours. As the seasons shift, September’s daylight reflects a delicate balance, offering just enough sunshine to enjoy outdoor activities while hinting at the approaching chill of October, which sees a further dip to 11 hours. This evolving daylight pattern not only highlights nature's rhythm but also sets the stage for the vibrant colors of fall that soon follow.

Average Daylight Hours in Suwon for September

The chart illustrates the variation in daylight duration in Suwon throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 53m10h 48m11h 57m13h 9m14h 9m14h 40m14h 24m13h 32m12h 23m11h 12m10h 9m9h 37m
Data source: Suwon daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Suwon

As September rolls into Suwon, South Korea, the winds begin to whisper a gentle transition from summer’s warmth. With an average wind speed of 2.7 m/s (6 mph), September maintains a delicate balance, slightly stronger than the summer months but still mild compared to the breezier days of early winter and the start of spring. This shift is inviting, creating a refreshing atmosphere perfect for outdoor activities. The steady yet soft winds hint at the changing seasons, echoing nature's subtle call for transformation as Suwon prepares for the vibrant hues and cooler breezes of autumn.

Average September Wind Speed in Suwon

The chart displays monthly wind speed patterns in Suwon, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.42.72.92.92.22.02.32.7 m/s2.42.72.9
Data source: Suwon September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Suwon Compares to Other Months

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

The weather conditions in September and January present a stark contrast. In September, temperatures range from a mild 9°C (48°F) at night to a warm average of 22°C (71°F), peaking at a scorching 31°C (88°F) during the day. This month is also characterized by relatively high humidity at 77%, along with significant rainfall measured at 136 mm (5.4 in) over 9 days. In stark contrast, January brings frigid temperatures, with lows plunging to -17°C (2°F) and an average temperature of -2°C (29°F), reaching a maximum of 13°C (55°F). Precipitation is minimal in January, totaling just 21 mm (0.8 in) over only 2 days, and humidity decreases to 71%. For more detailed information on January weather patterns, you can refer to Suwon weather in January.

September and February present contrasting weather conditions. September enjoys mild temperatures with an average of 22°C (71°F), peaking at a warm 31°C (88°F), while February is significantly colder, with an average of 0°C (33°F) and maximum temperatures reaching only 18°C (65°F). The humidity in September is notably higher at 77%, compared to February's more comfortable 65%. Additionally, September experiences much more precipitation, with 136 mm (5.4 in) over 9 days, whereas February has just 23 mm (0.9 in) spread across only 4 days. For more insights on February weather, visit Suwon weather in February.

September and March exhibit markedly different weather patterns. In September, temperatures range from a mild 9°C (48°F) at night to a warm average of 22°C (71°F) during the day, peaking at a high of 31°C (88°F). This month also experiences significant precipitation, totaling 136 mm (5.4 in) across 9 days, coupled with a higher humidity level of 77%. In contrast, March is much cooler, with nighttime temperatures dipping to -6°C (21°F) and an average of 7°C (44°F), reaching highs of 21°C (70°F). The total precipitation in March is significantly lower at 47 mm (1.9 in) over just 5 days, and humidity is also lower at 65%. For more detailed information, you can visit Suwon weather in March.

September and April present contrasting weather patterns, reflecting the transition between summer and autumn to early spring. In September, temperatures range from a minimum of 9°C (48°F) to a warm average of 22°C (71°F), peaking at 31°C (88°F). The month is also characterized by higher humidity at 77% and significant precipitation, with 136 mm (5.4 in) falling over 9 days. In contrast, April experiences cooler temperatures, with a minimum of -1°C (30°F) and an average of 12°C (54°F), reaching a maximum of 28°C (82°F). Rainfall is considerably lighter in April, totaling 54 mm (2.1 in) over just 5 days, accompanied by slightly lower humidity at 75%. For a more detailed look at the weather specifics in April, check out Suwon weather in April.

September and May present contrasting yet appealing weather conditions. In September, the temperatures range from a cooler minimum of 9°C (48°F) to a warm average of 22°C (71°F), peaking at a maximum of 31°C (88°F). Despite the warmth, the month experiences substantial precipitation, totaling 136 mm (5.4 in) over 9 days, with humidity levels hovering around 77%. In contrast, May has a slightly cooler temperature range, with minimums of 6°C (42°F) and an average of 18°C (64°F), while also reaching a maximum of 31°C (89°F). Rainfall in May is less frequent, amounting to 98 mm (3.9 in) over 8 days, and the humidity is a touch higher at 81%. For more detailed insights, check out Suwon weather in May.

Comparing the weather in September and June reveals some interesting contrasts. In September, temperatures range from a minimum of 9°C (48°F) to a maximum of 31°C (88°F), averaging about 22°C (71°F). This month experiences higher precipitation levels of 136 mm (5.4 inches) over approximately 9 days, making it considerably wetter than June. With a humidity level of 77%, September has a more varied climate, often mixing warm days with rainy spells.

In contrast, June features milder temperatures, with a minimum of 12°C (53°F) and a maximum of 33°C (91°F), also averaging around 22°C (72°F). The rainfall in June is notably less, at 80 mm (3.1 inches) over about 7 days, and the humidity is slightly higher at 85%. For more detailed insights into June weather, you can check Suwon weather in June. Overall, while both months share a similar average temperature, September tends to be wetter and cooler at its lowest point, while June remains drier and warmer.

When comparing the weather in September to that of July, one can see distinct differences. September experiences cooler temperatures, with a minimum of 9°C (48°F) and an average of 22°C (71°F), while July is significantly warmer, featuring a minimum temperature of 18°C (65°F) and an average of 26°C (79°F). Additionally, July tends to be wetter with 235 mm (9.3 in) of precipitation over 14 days, compared to September's 136 mm (5.4 in) spread across 9 days. Humidity levels are also higher in July at 91%, compared to September's 77%, contributing to a more sultry atmosphere. For a closer look at July's conditions, visit Suwon weather in July.

In comparing the weather of September and August, we see a notable shift in temperatures and precipitation. September experiences a cooler range, with minimum temperatures dropping to 9°C (48°F) and maximums reaching 31°C (88°F), whereas August is considerably warmer, with minimums at 16°C (61°F) and highs soaring to 38°C (101°F). Additionally, September has a lower average precipitation of 136 mm (5.4 in) over 9 days, while August is much wetter, accumulating 255 mm (10.1 in) across 14 days. Humidity levels are also higher in August at 91%, compared to September's 77%, contributing to a more uncomfortable feel during the summer's peak. For more detailed information on August weather, visit Suwon weather in August.

In comparing the weather between September and October, one can see notable transitions as autumn sets in. September features warmer temperatures, with a minimum of 9°C and an average of 22°C, peaking at a high of 31°C. This month also experiences significant rainfall, totaling 136 mm over 9 days, coupled with a humidity level of 77%. In contrast, October brings a marked drop in temperature, with a minimum of 1°C and an average of 15°C, while still reaching highs of 29°C. Precipitation is reduced to 62 mm over just 5 days, and humidity slightly increases to 79%. For more detailed insights into October's climate, you can explore Suwon weather in October.

September is characterized by significantly warmer temperatures, with a minimum of 9°C (48°F) and an average high of 31°C (88°F), making it feel much more summery. In contrast, November brings a notable chill, featuring temperatures that can drop to -5°C (23°F) and an average of 8°C (46°F). While September sees more rainfall (136 mm over 9 days) and relatively high humidity at 77%, November experiences much lighter precipitation of 54 mm over just 5 days and slightly higher humidity at 80%. For more detailed insights on November weather, you can visit Suwon weather in November.

In September, the weather is notably warmer and more humid, with average temperatures around 22°C (71°F) and maximums reaching as high as 31°C (88°F). The month also experiences significant rainfall, totaling 136 mm (5.4 in) over approximately 9 days. In contrast, December brings a dramatic shift, characterized by much colder temperatures, with averages plummeting to around 0°C (33°F) and lows dipping down to -14°C (8°F). Precipitation is limited to just 26 mm (1.0 in) over 5 days, and humidity decreases slightly to 74%. For more details on climate conditions during this season, check out Suwon weather in December.

Compare Suwon's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Suwon

As summer transitions to autumn, September in Suwon presents a unique tapestry of weather compared to the other months of the year. The temperatures remain relatively warm, offering a pleasant average that allows for both comfortable days and cool evenings. However, the notable increase in rainfall—along with a higher humidity level—marks a shift from the drier summer months. With precipitation occurring on about nine days, this month serves as a gentle reminder that fall is on the horizon. For a deeper understanding of how Suwon's climate shifts with the seasons, explore more at Suwon Climate.