Hainan weather in September
September is one of the least pleasant months in Hainan: highs of 29°C (85°F) and about 293 mm (11.5 in) of rain on average. Nights average 26°C (79°F) and cloud cover 64% (NASA POWER, 2001–2025 averages). It is the 2nd wettest month of the year and the 5th warmest. Compared with August, it is cooler and about as wet; October brings highs of 28°C (82°F) and 278 mm (10.9 in) of rain.
Figures are long-term averages for Haikou, the largest city in Hainan. See below for other places.
Is September a good time to visit Hainan?
least pleasant month Weather score 38/100.
September is one of the least pleasant months for weather in Hainan. For better conditions, consider Nov–Apr.
Does it rain a lot in Hainan in September?
Yes, it is one of the rainy months: about 293 mm (11.5 in) falls in an average September. It is the 2nd wettest month of the year.
How warm is Hainan in September?
Days average 29°C (85°F) and nights 26°C (79°F).
Hainan weather by month
| Month | High | Low | Rain | Cloud | Weather |
|---|---|---|---|---|---|
| January | 21°C (70°F) | 17°C (62°F) | 33 mm | 70% | best |
| February | 23°C (73°F) | 17°C (63°F) | 28 mm | 71% | best |
| March | 25°C (77°F) | 20°C (67°F) | 47 mm | 68% | best |
| April | 28°C (83°F) | 23°C (73°F) | 88 mm | 61% | best |
| May | 30°C (86°F) | 25°C (78°F) | 190 mm | 64% | fair |
| June | 30°C (87°F) | 27°C (80°F) | 205 mm | 74% | fair |
| July | 30°C (87°F) | 26°C (80°F) | 236 mm | 68% | least pleasant |
| August | 30°C (86°F) | 27°C (80°F) | 313 mm | 68% | least pleasant |
| September | 29°C (85°F) | 26°C (79°F) | 293 mm | 64% | least pleasant |
| October | 28°C (82°F) | 24°C (76°F) | 278 mm | 54% | least pleasant |
| November | 25°C (77°F) | 22°C (71°F) | 81 mm | 59% | best |
| December | 22°C (71°F) | 18°C (65°F) | 49 mm | 66% | best |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis). Page updated . How we rate months
Weather across Hainan in September
Weather can differ a lot within Hainan: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Haikou | 29°C (85°F) | 26°C (79°F) | 293 mm | least pleasant |
| Sanya | 29°C (85°F) | 23°C (74°F) | 329 mm | least pleasant |
| Wenchang | 30°C (86°F) | 25°C (77°F) | 309 mm | least pleasant |
| Wanning | 30°C (85°F) | 26°C (79°F) | 287 mm | least pleasant |
| Qionghai | 30°C (85°F) | 26°C (79°F) | 287 mm | least pleasant |
| Basuo | 30°C (85°F) | 24°C (76°F) | 285 mm | least pleasant |
| Xiuying | 30°C (85°F) | 26°C (79°F) | 276 mm | least pleasant |
| Nada | 30°C (85°F) | 23°C (74°F) | 304 mm | least pleasant |
| Wuzhishan | 29°C (83°F) | 21°C (70°F) | 331 mm | least pleasant |
| Qiongshan | 29°C (85°F) | 26°C (79°F) | 293 mm | least pleasant |
| Dacheng | 30°C (85°F) | 23°C (74°F) | 304 mm | least pleasant |
| Sandu | 29°C (85°F) | 27°C (80°F) | 263 mm | least pleasant |