Haikou weather in September
In September, Haikou has an average high of 29 °C85 °F and an average low of 26 °C79 °F, with about 293 mm12 in of precipitation. It is the 4th warmest month of the year and ranks 2nd for precipitation.
How September compares with other months
Compared with August, September is 0.5 °C0.9 °F cooler on average and drier by 20 mm0.8 in. Compared with October, September is 1.8 °C3.2 °F warmer on average and wetter by 16 mm0.6 in. Daylight lasts about 12.2 hours around the middle of the month. Average relative humidity is 85% and the average cloud amount 64%.
Is September a good time to visit Haikou?
September is not among the most comfortable months by our comfort score: it is hot (average high 29 °C85 °F), it is fairly wet (293 mm12 in) and it is humid (85%). The most comfortable months in Haikou are December–March.
What to wear in September
For Haikou in September, pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Haikou | 2985 | 2679 | 29312 |
| Xiuying | 3085 | 2679 | 27611 |
| Wenchang | 3086 | 2577 | 30912 |
| Qionghai | 3085 | 2679 | 28711 |
| Nada | 3085 | 2374 | 30412 |
| Zhanjiang | 2985 | 2780 | 28011 |
| Wanning | 3085 | 2679 | 28711 |
| Wuzhishan | 3085 | 2272 | 33113 |
| Lianjiang | 3086 | 2475 | 2459.6 |
Nearby places that are more than 1 °C1.8 °F cooler: Nada and Wuzhishan.
Other months in Haikou
- January21 °C70 °F / 17 °C62 °F
- February23 °C73 °F / 17 °C63 °F
- March25 °C77 °F / 20 °C67 °F
- April28 °C83 °F / 23 °C73 °F
- May30 °C86 °F / 25 °C77 °F
- June30 °C87 °F / 27 °C80 °F
- July30 °C87 °F / 26 °C80 °F
- August30 °C86 °F / 26 °C80 °F
- September29 °C85 °F / 26 °C79 °F
- October28 °C82 °F / 24 °C76 °F
- November25 °C77 °F / 22 °C71 °F
- December22 °C71 °F / 18 °C65 °F
Frequently asked questions
How warm is Haikou in September?
In September the average high in Haikou is 29 °C (85 °F) and the average low is 26 °C (79 °F).
Does it rain a lot in Haikou in September?
On average about 293 mm (11.5 in) of precipitation falls in September; it ranks 2nd of the 12 months.
Is September the warmest month in Haikou?
No. The warmest month in Haikou is June, with an average high of 30 °C (87 °F). The coldest month is January, with an average low of 17 °C (62 °F).
How long is the day in Haikou in September?
In the middle of September the day in Haikou lasts about 12.2 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Haikou in September?
The average relative humidity in September is about 85%. Combined with warm days, it can feel muggy.
How cloudy is Haikou in September?
On average about 64% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.