Hoi An weather in September
Hoi An averages 31°C by day and 25°C at night in September, with the sea at 31°C and about 285 mm of rain in the month. It cools by about 3°C into October.
Day
31°C
Night
25°C
Sea
31°C
Rain
285 mm
Flight from London
12h
What September feels like
September is hot but wet in Hoi An: rainy season, so pack for showers.
The sea is warm at 31°C: comfortable for long swims.
It is rainy season: about 285 mm of rain falls in the month.
That is 11°C warmer than an average September day in London.
Of the 56 sun destinations we track, Hoi An is the #13 warmest in September.
Going to Hoi An in September?
Share the TikToks and Instagram Reels you've saved for Hoi An to Dream Trip. It finds the places, pins them on a map and builds your days around them.
Want it warmer in September?
These are hotter than Hoi An this month for at most an hour and a half more flying:
Hoi An weather by month
September is highlighted. Compare with August and October, or see the full year in Hoi An.
| Month | Day | Night | Sea | Rain |
|---|---|---|---|---|
| January | 24°C | 20°C | 24°C | 167 mm |
| February | 25°C | 20°C | 24°C | 85 mm |
| March | 27°C | 22°C | 25°C | 67 mm |
| April | 30°C | 24°C | 26°C | 65 mm |
| May | 32°C | 26°C | 28°C | 89 mm |
| June | 34°C | 27°C | 30°C | 103 mm |
| July | 33°C | 27°C | 30°C | 153 mm |
| August | 34°C | 27°C | 31°C | 154 mm |
| September | 31°C | 25°C | 31°C | 285 mm |
| October | 28°C | 24°C | 29°C | 506 mm |
| November | 27°C | 23°C | 27°C | 432 mm |
| December | 25°C | 21°C | 25°C | 376 mm |
Hoi An in September: quick answers
Is Hoi An hot in September?
September is hot but wet in Hoi An: rainy season, so pack for showers. Average highs are 31°C and lows 25°C.
Can you swim in Hoi An in September?
The sea is warm at 31°C: comfortable for long swims.
Does it rain in Hoi An in September?
It is rainy season: about 285 mm of rain falls in the month.
What is the warmest month in Hoi An?
June, at an average high of 34°C. The coolest is January at 24°C.
How long is the flight to Hoi An from the UK?
About 12h direct from London, estimated from the 9,873 km distance. Check your airline for exact times.
Still choosing? See where is hot in September for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in September from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. Rain is the average monthly total. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning Hoi An in September?
Save the restaurants, beaches and views you find on TikTok and Instagram for Hoi An straight to a map, then let Dream Trip turn them into a day-by-day plan.
