September Weather in Hong Kong, Hong Kong

Last updated: August 21, 2025

September in Hong Kong is marked by warm temperatures and high humidity, making it an intriguing time to experience the city. With daytime highs reaching a maximum of 32°C (91°F) and an average of 28°C (83°F), the warmth lingers, while the nights cool down to a minimum of 24°C (76°F). However, the month is also known for its frequent rains, accumulating approximately 223 mm (8.8 in) over 22 days, creating a lush, vibrant atmosphere. Travelers can expect typical tropical conditions, with humidity levels averaging around 75%, enhancing the city's vibrant energy but necessitating preparation for the occasional downpour.

September Temperature in Hong Kong

September in Hong Kong marks the tail end of summer, with temperatures ranging from a comfortable 24°C (76°F) to a warm 32°C (91°F). The average temperature settles at 28°C (83°F), reflecting a slight dip compared to the sweltering peak of summer months like August, which often sees highs of 34°C (93°F). As the month progresses, residents and visitors enjoy gradually cooler evenings, reminiscent of the delightful transition into autumn. This blend of warmth, coupled with relatively high humidity, creates an atmosphere that is both lively and inviting, perfect for exploring the city's vibrant street life and stunning outdoor attractions.

September Weather in Hong Kong: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Hong Kong, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hong Kong, 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).
JanFebMarAprMayJunJulAugSepOctNovDec636369737983848382787265
Data source: Temperature data for Hong Kong generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Hong Kong

In September, Hong Kong experiences a significant shift in precipitation, with 223 mm (8.8 in) of rain recorded over 22 days. This marks a notable decrease from the hefty 384 mm (15.1 in) seen in August, yet the rainfall remains substantial as the city transitions into autumn. September's weather continues the trend of the summer months, characterized by frequent, albeit lighter, showers compared to the heavy downpours of the preceding months. The combination of humidity and intermittent rainfall creates a lush, vibrant environment, making it clear that while the monsoon season is tapering off, the city's rich greenery benefits greatly from this continued precipitation. Overall, September serves as a reminder of Hong Kong's dynamic climate, bridging the gap from the torrid summer to the more tempered autumn.

September Precipitation Trends in Hong Kong

The chart displays monthly precipitation patterns in Hong Kong, 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 Hong Kong, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec215260931713252193842231893631
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hong Kong

As summer fades, September's humidity in Hong Kong settles at a comfortable 75%, marking a noticeable decline from the oppressive 88% levels of July and August. This reduction signals the transition to a more bearable autumn, with humidity beginning to mirror the drier conditions typical of the upcoming months. Interestingly, September's moisture levels are a touch lower than the spring months, where humidity reached 73% in March and hovered around the 71% in April. As the year progresses, it becomes evident that both October and November will offer even drier air, often appreciated by locals and visitors alike. Such seasonal fluctuations enhance the unique charm of Hong Kong's climate, making each month a distinct experience.

September Average Humidity in Hong Kong

This chart illustrates the average monthly humidity levels in Hong Kong, 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 Hong Kong is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec64%68%73%71%79%77%88%88%75%65%64%69%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hong Kong

September in Hong Kong sees a UV Index of 12, maintaining an extreme exposure category that has characterized the summer months. With a burn time of just 10 minutes, it's crucial for residents and visitors alike to take sun safety seriously, as the high levels of UV radiation persist. This trend of elevated UV levels continues from the peak summer months, reflecting a consistent pattern of extreme conditions from May through September. As the sun begins to lower in October, there is a slight reprieve with an index of 11, though vigilance is still essential. For more detailed insights, you can explore the Hong Kong UV Index. Stay protected and enjoy the vibrant energy of the city!

Maximum UV Index Levels in Hong Kong for September

The chart shows the monthly maximum UV Index (UVI) for Hong Kong 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 Hong Kong typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec710121214131313121197
Data source: Hong Kong 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 Hong Kong

As summer gives way to autumn, September in Hong Kong shines with a glorious 288 hours of sunshine, making it one of the sunniest months of the year. Following a vibrant July, which boasted the highest at 323 hours, September maintains a strong position while showing a notable decrease compared to its peak. The month continues to capture the warmth of the summer, with longer days and bright skies that invite outdoor exploration. This trend highlights a gradual shift from the intense summer sun to the softer golden hues of autumn, as the city's vibrant lifestyle thrives under the radiant skies. Overall, September stands out as a perfect transition period, balancing the lingering summer heat with the promise of the cooler months approaching.

Monthly Sunshine Duration in Hong Kong: September Highlighted

The September sunshine duration represents the total number of hours Hong Kong 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.
JanFebMarAprMayJunJulAugSepOctNovDec216h251h274h263h301h274h323h280h288h280h262h264h
Data source: Hong Kong September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Hong Kong During September

In Hong Kong, September presents a refreshing shift in the weather patterns, boasting a 45% likelihood of sunny days. This improvement contrasts sharply with the overcast months of June and August, where the chances of sunshine plummet to a mere 12% and 15% respectively. As the summer heat wanes, September offers a welcome balance, drawing closer to the sunnier winter months of November (62%) and December (50%). While not as bright as January or February, where the sun shines about 61% and 60% of the time, September stands out as a promising transitional month, inviting both locals and tourists to enjoy the lingering warmth under clearer skies.

Percentage of Sunny Days in September in Hong Kong

The chart illustrates the percentage of sunny days in Hong Kong 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 Hong Kong experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec61%60%43%42%30%12%31%15%45%36%62%50%
Data source: Hong Kong September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Hong Kong in September

As summer fades into autumn, September in Hong Kong experiences a transition in daylight duration, offering approximately 12 hours of sunlight. This mirrors the longer days of March to August, where an abundance of daylight reaches a peak in the summer months, showcasing 13 hours during June and July. Following September, daylight begins its gradual decline into the shorter days of October and November, where 11 hours of sunlight becomes the norm. Overall, September reflects a balance, capturing the last vestiges of summer's radiance while hinting at the cozy embrace of autumn.

Average Daylight Hours in Hong Kong for September

The chart illustrates the variation in daylight duration in Hong Kong throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 55m11h 23m12h 1m12h 39m13h 11m13h 27m13h 19m12h 51m12h 14m11h 36m11h 3m10h 46m
Data source: Hong Kong daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Hong Kong

As September rolls into Hong Kong, the average wind speed dips to a gentle 3.2 m/s (7 mph), marking the city's calmest month of the year. This decline follows a gradual decrease from the breezier spring days, reflecting the transition into the warmer autumn season. From January to September, the wind has consistently softened, peaking in October with a notable rebound to 6.4 m/s (14 mph). This predictable rhythm of wind patterns not only shapes the city's climate but also influences the vibrant atmosphere, inviting residents and visitors alike to enjoy the serene beauty of Hong Kong's landscapes. As the urban hum settles into a more tranquil cadence, the embracing warmth of September welcomes leisurely strolls and tranquil moments.

Average September Wind Speed in Hong Kong

The chart displays monthly wind speed patterns in Hong Kong, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.14.44.74.63.74.23.83.43.2 m/s6.44.95.6
Data source: Hong Kong September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Hong Kong Compares to Other Months

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

September and January present a striking contrast in weather conditions. In September, temperatures range from a minimum of 24°C (76°F) to a maximum of 32°C (91°F), with an average temperature of 28°C (83°F). This month sees significant rainfall, totaling 223 mm (8.8 inches), and experiences precipitation on about 22 days, accompanied by high humidity at 75%. In stark contrast, January’s temperatures are much cooler, with a minimum of 8°C (46°F), an average of 17°C (63°F), and a maximum of 24°C (75°F). Rainfall is minimal in January, accumulating only 21 mm (0.8 inches) across just 4 days, and humidity levels drop to 64%. For more details on winter weather in Hong Kong, visit Hong Kong weather in January.

In comparing the weather of September and February, September displays a much warmer climate, with average temperatures ranging from a minimum of 24°C (76°F) to a maximum of 32°C (91°F). This month also experiences significant rainfall, totaling 223 mm (8.8 in) over approximately 22 days, and a humidity level of 75%, creating a muggy atmosphere. In contrast, February offers a cooler environment, with temperatures ranging from a low of 7°C (45°F) to a high of 24°C (76°F), and significantly less precipitation at only 52 mm (2.0 in) over 7 days, accompanied by a lower humidity of 68%. For more details on the weather conditions during this month, you can explore Hong Kong weather in February.

When comparing the weather between September and March, it's clear that September is significantly warmer and wetter. In September, temperatures range from a minimum of 24°C (76°F) to a maximum of 32°C (91°F), with an average temperature of 28°C (83°F). This month also sees high humidity at 75% and substantial rainfall, totaling 223 mm (8.8 in) over 22 days. In contrast, March offers a much cooler climate, with temperatures ranging from a low of 12°C (54°F) to a high of 27°C (80°F) and an average of 21°C (70°F). The precipitation during this month is considerably less, at 60 mm (2.4 in) over just 10 days, accompanied by slightly lower humidity at 73%. For more detailed insights on the weather patterns in March, you can check Hong Kong weather in March.

September weather is characterized by warmer temperatures, with a minimum of 24°C (76°F) and an average of 28°C (83°F), peaking at a high of 32°C (91°F). In contrast, April experiences milder conditions, with temperatures ranging from a minimum of 14°C (58°F) to a maximum of 29°C (85°F) and an average of 23°C (73°F). Additionally, September is more humid with an average humidity of 75% and significantly higher precipitation, totaling 223 mm (8.8 in) across 22 days, compared to April's 93 mm (3.7 in) over 12 days. For more details, you can visit Hong Kong weather in April.

When comparing the weather in September and May, we can see some notable differences. September tends to be warmer with average temperatures reaching 28°C (83°F) and maximums hitting 32°C (91°F), while May has a slightly cooler average temperature of 26°C (79°F) and can peak at 33°C (92°F). However, September experiences higher humidity at 75% compared to May's 79%. Additionally, September receives more rainfall, with a total of 223 mm (8.8 in) over 22 days, whereas May sees 171 mm (6.7 in) of precipitation across 18 days. For more specific details about May's weather conditions, check out Hong Kong weather in May.

When comparing the weather in September and June, both months share similar temperature ranges, with minimums around 24°C (76°F) and average temperatures hovering around 28°C (83°F). However, June tends to be slightly warmer, reaching a maximum of 33°C (91°F), compared to September's maximum of 32°C (91°F). In terms of precipitation, June is notably wetter, receiving 325 mm (12.8 in) of rain over 24 days, while September sees 223 mm (8.8 in) across 22 days. The humidity levels are also comparable, with September at 75% and June at 77%. For a detailed look at the weather specifics in June, you can visit Hong Kong weather in June.

In comparing the weather in July and September, we find that July typically experiences slightly warmer temperatures, with average highs reaching 33°C (92°F) compared to September's max of 32°C (91°F). The minimum temperature in July is also marginally higher at 25°C (78°F) versus September's 24°C (76°F). In terms of precipitation, both months are quite wet, with September seeing 223 mm (8.8 in) of rain over 22 days, while July has slightly less at 219 mm (8.6 in) over 24 days. Additionally, July boasts higher humidity levels at 88% compared to September's 75%. For a more detailed look at July weather, you can visit Hong Kong weather in July.

In comparing the weather of September and August, both months reveal warm temperatures, but September is slightly cooler. The minimum temperature in September is 24°C (76°F) compared to August's 26°C (78°F), while the average remains the same at 28°C (83°F). However, August experiences higher maximum temperatures of 34°C (93°F) versus September's 32°C (91°F). Additionally, September sees less precipitation at 223 mm (8.8 in) over 22 days, compared to August's significantly higher 384 mm (15.1 in) over 25 days, indicating a drier month. Humidity levels also decrease in September to 75%, down from August's higher 88%. For more detailed information, you can visit Hong Kong weather in August.

In comparing the weather between September and October, notable changes emerge. September experiences warmer conditions with minimum temperatures around 24°C (76°F) and an average of 28°C (83°F), while October sees a cooler dip, featuring minimum temperatures of 17°C (64°F) and an average of 26°C (78°F). Despite both months reaching a maximum of 32°C (91°F), October generally has lower humidity at 65% compared to September's 75%. Additionally, October has less precipitation, totaling 189 mm (7.4 in) over just 10 days, in contrast to September's 223 mm (8.8 in) spread across 22 days. For more detailed insights, visit Hong Kong weather in October.

September and November present markedly different weather patterns. In September, temperatures are notably warmer, with a minimum of 24°C (76°F) and an average of 28°C (83°F), peaking at 32°C (91°F). This month also experiences high humidity at 75% and significant rainfall, with 223 mm (8.8 in) spread over 22 days. In contrast, November sees cooler conditions, with temperatures ranging from a minimum of 16°C (60°F) to an average of 22°C (72°F), and a maximum of 28°C (82°F). Rainfall diminishes significantly to just 36 mm (1.4 in) over 4 days, and humidity drops to 64%. For more details on November weather in Hong Kong, check out Hong Kong weather in November.

September tends to be quite warm and humid, with average temperatures hovering around 28°C (83°F) and peaks reaching up to 32°C (91°F). The month is characterized by high humidity levels of 75% and significant rainfall, averaging 223 mm (8.8 in) over 22 days. In contrast, December brings a much cooler climate, with temperatures ranging from a minimum of 10°C (49°F) to a maximum of 26°C (78°F), resulting in an average temperature of 18°C (65°F). Precipitation drops drastically to just 31 mm (1.2 in) over only 4 days, and humidity levels decrease slightly to 69%. For more detailed information, you can visit Hong Kong weather in December.

Compare Hong Kong's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Hong Kong

As summer begins to wane, September in Hong Kong presents a unique weather experience, marked by warm temperatures and noticeable humidity. With an average warmth that hovers around a comfortable 28°C, the city often feels vibrant and lively, though it also sees a significant amount of rainfall, leading to a surprisingly wet month. This atmospheric shift contrasts sharply with the drier, more stable conditions typical of the winter months, offering a taste of the region's tropical climate. While the heat remains comparable to the peak summer months, the increased likelihood of rain and higher humidity can create a more unpredictable and dynamic environment. For more insights on what to expect throughout the year, check out the detailed Hong Kong Climate.