Haikou weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Fair
Best time to visit: October – April
What is the weather like in Haikou in September?
In September, Haikou is hot: daytime highs average 29 °C, and even at night it stays warm at around 26 °C. The sea averages 28.3 °C – lovely and warm for swimming. Expect around 6 hours of sunshine a day. It rains often – on about 19 days, adding up to 229 mm. On about 10 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, September is a so-so month for a holiday in Haikou.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 41 | 45 | 62 |
| Day | 31° | 29° | 27° |
| Night | 27° | 26° | 25° |
| Sea | 29° | 28° | 27° |
| Sun | 7 h | 6 h | 5 h |
| Rain days | 21 | 19 | 15 |
More details for September
- Daylight
- 12 h 17 min06:26 – 18:42
- UV index
- 11 · extremeclear sky, noon (estimate)All months
- Muggy days
- 30 daysdew point 18 °C or moreAll months
- Wind
- 20 km/haverage daily peakAll months
- Cloud cover
- 68 %on averageAll months
- Hot days
- 10 days30 °C or moreAll months
- Time zone
- UTC+8Asia/Shanghai
How the score comes together
- Temperatureweight 50 %71 %
- Sunshineweight 20 %47 %
- Few rainy daysweight 30 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Insect repellent
- Rain jacket or umbrella
Haikou in September: quick answers
Is Haikou hot in September?
Yes. In September, Haikou is hot: daytime highs average 29 °C and nights stay around 26 °C. On about 10 days the thermometer climbs to 30 °C or more.
Can you swim in Haikou in September?
Yes. In September the sea averages 28.3 °C – lovely and warm for swimming.
Does it rain much in Haikou in September?
It rains often – on about 19 days, adding up to 229 mm.
Haikou month by month
The whole year in HaikouAll destinations: ChinaWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences