September Weather in Haikou, China

Last updated: August 21, 2025

In September, Haikou, China experiences a warm and humid climate, with temperatures ranging from a minimum of 20°C (68°F) to a maximum of 35°C (96°F), leading to an average temperature of 27°C (81°F). This vibrant month sees about 105 mm (4.1 in) of rainfall spread over 15 days, contributing to the lush scenery and keeping the humidity around a sticky 70%. Visitors can expect a tropical atmosphere, perfect for those who enjoy warm weather, but should also be prepared for intermittent showers throughout the month.

September Temperature in Haikou

In September, Haikou, China, experiences a warm transition towards the autumn months with temperatures that reflect the lingering summer heat. The minimum temperature hovers around a comfortable 20°C (68°F), while the average ramps up to a balmy 27°C (81°F), peaking at a sizzling 35°C (96°F). This month marks a gradual decline from the stifling July and August heat, yet remains pleasantly warm, inviting outdoor activities. As the temperatures begin to cool slightly, the shift hints at the approaching fall, making September an ideal time to enjoy the beautiful coastal city before the cooler days of October set in.

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

The chart illustrates September temperature patterns in Haikou, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Haikou, 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).
JanFebMarAprMayJunJulAugSepOctNovDec545459667480848481746658
Data source: Temperature data for Haikou 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 Haikou

September in Haikou, China, experiences a moderate increase in precipitation, with 105 mm (4.1 in) of rain falling over 15 days. This marks a notable transition from the intense rainfall of August, which peaked at 260 mm (10.2 in), signaling the tail end of the wet season. Compared to earlier months, September's rainfall is substantial yet less extreme, making it a significant month for moisture accumulation without overwhelming downpours. As the region moves into October, a slight decline in precipitation is expected, reflecting the gradual shift towards drier autumn months. Overall, September strikes a balance, ensuring the landscape remains lush while paving the way for a change in weather patterns.

September Precipitation Trends in Haikou

The chart displays monthly precipitation patterns in Haikou, 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 Haikou, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec45701238815526983260105716549
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Haikou

In September, Haikou experiences a dip in humidity, averaging 70%, which marks the end of its typically wet summer months. This slight decrease is notable after a peak of 85% in May and consistent levels ranging from 81% to 84% during the summer. As the year progresses, humidity begins to rise again, reaching 73% in October. Overall, Haikou's climate demonstrates a distinctive trend where humidity levels climb in the spring, peak in the summer, and taper off in early autumn, reflecting the region's tropical characteristics. This fluctuation not only influences the weather but also adds a dynamic quality to life in this vibrant coastal city throughout the year.

September Average Humidity in Haikou

This chart illustrates the average monthly humidity levels in Haikou, 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 Haikou is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec73%73%80%81%85%81%84%83%70%73%77%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Haikou

In September, Haikou experiences a high UV Index of 11, which falls into the extreme exposure category, requiring a burn time of just 10 minutes. As the summer months wane, the UV levels begin to taper from the peak of 13 seen in July and August, yet they remain significantly elevated, emphasizing the need for sun protection. This trend of extreme UV exposure from April through September underscores the importance of cautious sun practices to safeguard against potential skin damage. To learn more about the UV Index and protect yourself effectively, visit Haikou UV Index.

Maximum UV Index Levels in Haikou for September

The chart shows the monthly maximum UV Index (UVI) for Haikou 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 Haikou typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec7911121213131311986
Data source: Haikou 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 Haikou

September in Haikou, China, shines brightly with 294 hours of sunlight, marking a delightful transition from the peak summer months. Following July's impressive 331 hours and August's 312 hours, the sun continues to grace the city with generous rays as it shifts into autumn. This month not only retains a high sunshine count but also showcases a gradual decline compared to the summer months, hinting at the seasonal changes ahead. As the days shorten, the warmth of September remains inviting, creating a perfect backdrop for outdoor adventures and seaside relaxation before the cooler months set in.

Monthly Sunshine Duration in Haikou: September Highlighted

The September sunshine duration represents the total number of hours Haikou 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.
JanFebMarAprMayJunJulAugSepOctNovDec188h232h272h274h297h260h331h312h294h265h228h215h
Data source: Haikou September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Haikou During September

In Haikou, China, September offers a notable revival of sunny weather, with a chance of sunshine reaching 52%, closely mirroring the sunlit days of January. Following the damp and less sunny months of summer, September marks a shift towards clearer skies, providing a refreshing respite for outdoor activities. As the year progresses, the likelihood of sunny days fluctuates, peaking in the winter months and dipping significantly in the height of summer. This makes September a sweet spot for those seeking to enjoy the warmth and light before the cooler months set in.

Percentage of Sunny Days in September in Haikou

The chart illustrates the percentage of sunny days in Haikou 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 Haikou experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec53%46%39%30%15%5%27%22%52%27%34%34%
Data source: Haikou September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Haikou in September

September marks a gentle transition in Haikou, China, as daylight hours begin to wane from the summer peak. With 12 hours of daylight, this month mirrors April and March, signaling a gradual shift from the prolonged brightness of summer. As daylight duration transitions from the highs of 13 hours in June through August, the days still retain warmth and a vibrant atmosphere before dipping to 11 hours in October. This pattern underscores a rhythmic ebb and flow of daylight that characterizes Haikou's tropical climate, inviting residents and visitors alike to savor the lingering daylight before the cooler months set in.

Average Daylight Hours in Haikou for September

The chart illustrates the variation in daylight duration in Haikou throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 43m11h 16m12h12h 45m13h 23m13h 41m13h 32m12h 59m12h 16m11h 31m10h 53m10h 33m
Data source: Haikou daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Haikou

In September, Haikou experiences a gentle shift in its winds, with an average speed of 3.5 m/s (8 mph), marking the year's calmest month. This subtle decline follows a more mild summer, where wind speeds hovered between 4.1 m/s and 4.7 m/s from June to August. As the month unfolds, residents and visitors alike enjoy peaceful breezes that contrast sharply with the stronger gusts typical of October, which surges to 6.5 m/s (14 mph). This trend highlights a transitional phase in Haikou's climatic rhythm, as nature prepares for the more robust winds of autumn, offering a serene yet captivating atmosphere perfect for leisurely outdoor activities.

Average September Wind Speed in Haikou

The chart displays monthly wind speed patterns in Haikou, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.34.64.14.83.94.24.74.13.5 m/s6.55.15.7
Data source: Haikou September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Haikou Compares to Other Months

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

September and January show distinct differences in weather patterns. In September, temperatures range from a minimum of 20°C (68°F) to a maximum of 35°C (96°F), with an average temperature of 27°C (81°F). This month also experiences considerable rainfall, with 105 mm (4.1 in) of precipitation over about 15 days and a humidity level around 70%. Conversely, January brings much cooler temperatures, with a minimum of 3°C (38°F) and a maximum of 24°C (76°F), averaging at 12°C (55°F). The precipitation is significantly lower at 45 mm (1.8 in) over just 6 days, while humidity remains fairly high at 73%. For more details on January weather specifics, visit Haikou weather in January.

In September, the weather is notably warm, with temperatures ranging from a minimum of 20°C (68°F) to a maximum of 35°C (96°F), and an average of 27°C (81°F). This month also sees significant rainfall, with precipitation of 105 mm (4.1 in) over approximately 15 days, leading to a humidity level of 70%. In contrast, February experiences much cooler temperatures, with a minimum of 4°C (40°F), an average of 12°C (54°F), and a maximum of 24°C (76°F). February also has less rainfall, totaling 70 mm (2.8 in) over 9 days, and a slightly higher humidity of 73%. For more detailed information about February weather, you can visit Haikou weather in February.

September and March present distinct weather patterns that reflect the transition from summer to spring. In September, temperatures typically range from a comfortable 20°C (68°F) to a hot 35°C (96°F), with an average of 27°C (81°F). The month also experiences significant rainfall, totaling 105 mm (4.1 in) over 15 days, accompanied by a humidity level of 70%. In contrast, March features cooler temperatures, with a minimum of 7°C (46°F) and a maximum of 26°C (80°F), averaging just 15°C (60°F). Although March receives slightly more precipitation at 123 mm (4.8 in) over 14 days, the humidity is higher at 80%. For more detailed insights, you can check Haikou weather in March.

In September, the weather is significantly warmer than in April, with average temperatures reaching 27°C (81°F) and maximums hitting 35°C (96°F), compared to April's average of 19°C (66°F) and a maximum of 29°C (84°F). Additionally, September experiences more humidity at 70%, while April's humidity is slightly higher at 81%. Precipitation is also a factor, with September receiving 105 mm (4.1 in) over approximately 15 days, whereas April sees a total of 88 mm (3.5 in) across about 11 days. For more specific details on April weather, you can check Haikou weather in April.

In September, the weather typically features warmer temperatures, with a minimum of 20°C (68°F) and an average high of 35°C (96°F), while May boasts cooler temperatures, such as a minimum of 14°C (57°F) and an average maximum of 32°C (90°F). Both months experience similar levels of precipitation, with September receiving about 105 mm (4.1 in) and May seeing a higher total of 155 mm (6.1 in), yet they share a commonality with precipitation occurring on around 15 days. Additionally, humidity levels in May are higher, averaging 85% compared to September's 70%. For more detailed insights, check out Haikou weather in May.

When comparing the weather in September and June, we note that both months feature a similar temperature range, with minimums around 20°C (68°F) and average highs of 27°C (81°F). However, September tends to be slightly warmer, with maximum temperatures reaching up to 35°C (96°F) compared to June's maximum of 33°C (92°F). September also experiences less rainfall, accumulating 105 mm (4.1 in) over 15 days, whereas June sees a much higher precipitation of 269 mm (10.6 in) across 18 days. Additionally, humidity is slightly lower in September at 70%, while June's humidity is higher at 81%. For more detailed information, you can check out Haikou weather in June.

In comparing the weather of September and July, September shows slightly cooler temperatures, with averages around 27°C (81°F) compared to July's 29°C (84°F). Both months peak at a maximum of 35°C (95-96°F); however, September tends to have more rainfall, with 105 mm (4.1 in) over 15 days, whereas July receives 83 mm (3.3 in) over just 13 days. Humidity levels are also higher in July at 84%, compared to September's 70%. For a more detailed look at July's weather patterns, check out Haikou weather in July.

In comparison to August, September experiences a slightly cooler temperature range, with minimums of 20°C (68°F) and an average of 27°C (81°F), compared to August's minimum of 25°C (76°F) and average of 29°C (84°F). While both months reach a maximum temperature of around 35°C (95°F to 96°F), September is generally more comfortable due to lower humidity levels—70% compared to August's 82%. Additionally, September sees less rainfall, with 105 mm (4.1 in) over 15 days, in contrast to August’s substantial 260 mm (10.2 in) over 20 days. For more details, you can check Haikou weather in August.

September and October exhibit notable differences in weather patterns. September typically presents warmer temperatures, with a minimum of 20°C (68°F) and an average high reaching 35°C (96°F). In contrast, October sees slightly cooler temperatures, starting at a low of 16°C (60°F) and peaking at 33°C (92°F), with an average of 23°C (74°F). Additionally, September experiences more precipitation, averaging 105 mm (4.1 in) over 15 days, compared to October's reduced rainfall of 71 mm (2.8 in) across 12 days. Humidity levels are relatively similar, hovering around 70% in September and 73% in October. For more details on October weather specifically in Haikou, you can visit Haikou weather in October.

September typically offers a hot and humid climate, with average temperatures reaching 27°C (81°F) and highs peaking at 35°C (96°F). The month is characterized by significant rainfall, totaling 105 mm (4.1 in) over about 15 days, contributing to a humidity level of 70%. In contrast, November presents a cooler and drier atmosphere, with temperatures dropping to an average of 19°C (67°F) and maximums around 28°C (83°F). The precipitation decreases to 65 mm (2.6 in) over approximately 10 days, while humidity rises slightly to 77%. For more details on November's specific conditions, check out Haikou weather in November.

September and December showcase a stark contrast in weather conditions. In September, temperatures range from a minimum of 20°C (68°F) to a maximum of 35°C (96°F), with an average of 27°C (81°F). This month also experiences significant rainfall, with about 105 mm (4.1 in) over 15 days and a humidity level of 70%. In contrast, December features much cooler temperatures, with a minimum of 7°C (45°F) and a maximum of 25°C (77°F), averaging 14°C (58°F). Precipitation decreases to 49 mm (1.9 in) over just 9 days, while humidity rises slightly to 79%. For more details on December weather, you can refer to Haikou weather in December.

Compare Haikou's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Haikou

As September unfolds in Haikou, the weather begins to show a distinct shift from the sweltering heights of summer. With temperatures averaging around 27°C (81°F), it offers a welcome respite from the peak heat, while still allowing for warm days. Rainfall makes its presence felt, with about 15 days of precipitation contributing to a 105 mm (4.1 in) total, creating a more humid atmosphere at around 70%. This blend of warmth and moisture not only enriches the landscape but also signals the gradual transition towards autumn. For more insights on what to expect throughout the year, check out Haikou Climate.