Click on a day for an hourly weather forecast
The weather in Hainan in September is very hot. The average temperatures are between 24°C and 31°C, drinking water regularly is advisable.
You can expect rain for roughly half of the month of September in Hainan. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Hainan in September 2025.
If you’re planning to visit Hainan in the near future, we highly recommend that you review the 14 day weather forecast for Hainan before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 22° / 15° | 5 | 26 | 0 | 48 mm | Good | Hainan in January |
| February | 26° / 17° | 3 | 26 | 0 | 33 mm | Perfect | Hainan in February |
| March | 30° / 20° | 6 | 25 | 0 | 77 mm | Good | Hainan in March |
| April | 32° / 22° | 12 | 18 | 0 | 178 mm | Ok | Hainan in April |
| May | 33° / 24° | 17 | 14 | 0 | 266 mm | Ok | Hainan in May |
| June | 34° / 25° | 16 | 14 | 0 | 214 mm | Bad | Hainan in June |
| July | 33° / 24° | 16 | 15 | 0 | 237 mm | Ok | Hainan in July |
| August | 32° / 24° | 17 | 14 | 0 | 334 mm | Ok | Hainan in August |
| September | 31° / 24° | 14 | 16 | 0 | 248 mm | Ok | Hainan in September |
| October | 28° / 21° | 10 | 21 | 0 | 225 mm | Good | Hainan in October |
| November | 26° / 19° | 6 | 24 | 0 | 98 mm | Perfect | Hainan in November |
| December | 23° / 16° | 4 | 27 | 0 | 54 mm | Perfect | Hainan in December |