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The weather in Vientiane in September is very hot. The average temperatures are between 24°C and 32°C, drinking water regularly is advisable.
There’s going to be many days of rain during the month of September in Vientiane.
Vientiane should expect an average of 15 to 22 days of rain, so be sure to bring along a waterproof jacket to stay dry this month!
Our weather forecast can give you a great sense of what weather to expect in Vientiane in September 2025.
If you’re planning to visit Vientiane in the near future, we highly recommend that you review the 14 day weather forecast for Vientiane before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 30° / 17° | 1 | 30 | 0 | 21 mm | Good | Vientiane in January |
| February | 34° / 21° | 0 | 28 | 0 | 11 mm | Ok | Vientiane in February |
| March | 36° / 24° | 2 | 29 | 0 | 39 mm | Ok | Vientiane in March |
| April | 38° / 26° | 4 | 26 | 0 | 91 mm | Bad | Vientiane in April |
| May | 36° / 26° | 10 | 22 | 0 | 282 mm | Bad | Vientiane in May |
| June | 33° / 25° | 13 | 17 | 0 | 352 mm | Ok | Vientiane in June |
| July | 31° / 24° | 18 | 13 | 0 | 476 mm | Ok | Vientiane in July |
| August | 31° / 24° | 17 | 14 | 0 | 515 mm | Ok | Vientiane in August |
| September | 32° / 24° | 15 | 15 | 0 | 362 mm | Ok | Vientiane in September |
| October | 31° / 22° | 6 | 25 | 0 | 141 mm | Good | Vientiane in October |
| November | 31° / 20° | 1 | 29 | 0 | 33 mm | Good | Vientiane in November |
| December | 29° / 18° | 0 | 31 | 0 | 12 mm | Good | Vientiane in December |