Vietnam Hoi An Weather in September (Monsoon Begins) — Climate Guide
September (Monsoon Begins) in Hoi An is moderate
September (Monsoon Begins) is moderate for Hoi An.
Monsoon begins in earnest — 250mm rain + Hoi An flood risk. Hotels drop 30-50%. Korean Chuseok creates a brief travel window.
Travel score
Monsoon begins — value travelers + Chuseok travelers welcome
September (Monsoon Begins) Weather at a Glance
September is the wet season's onset. 31/24°C with humidity climbing to 82%. 250mm rain across 12 days = frequent heavy showers + occasional flooding. Hoi An Old Town can flood 1-2 times per month with knee-deep water in streets (locals use sampan boats). Mid-Autumn Festival (varies by year, often Sep 25-27 in 2026) brings traditional children's lantern parades.
September (Monsoon Begins) Travel Advice
Korean Chuseok (Sep 24-27 in 2026) creates a brief premium window — book 2+ months ahead. Best value weeks: Sep 1-23 + Sep 28-30. Bring serious rain gear. Cham Islands largely canceled. Focus on Old Town + tailors + cooking class + indoor activities. The Mid-Autumn Festival full moon + monthly Lantern Festival are special.
Flying In from Overseas
Korean Chuseok (Sep 25, 2026) brings brief Korean family surge. Western backpackers seeking value visit. Direct DAD flights $300-500 (50% below summer peak).
September (Monsoon Begins) Pricing Trends
Anantara Hoi An $200-350/night (40% off peak), boutique $80-180/night, hostels $8-25/night. Chuseok (Sep 24-27) adds 30% premium.
Hoi An September (Monsoon Begins) Weather Stats
Avg High
31°C
Avg Low
24°C
Rainy Days
12
250mm total
Sunshine
6h
Daily avg
Humidity
82%
high
UV Index
8
Very high
Wind
10 km/h
Gusts 30
Sea Temp
28°C
swimming rough
Crowds
Quiet
At attractions
September (Monsoon Begins) Sunrise & Sunset
Air Quality
PM2.5
15 μg/m³
PM10
25 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
35°C
Nighttime
25°C
Humidity and wind affect how the actual temperature feels.
Wind
10 km/h
Max gust 30 km/h
Activities Recommended for September (Monsoon Begins)
September (Monsoon Begins) Travel Pros & Cons
Pros
- Hotels 30-50% cheaper
- Lowest crowds of year (outside Chuseok)
- Mid-Autumn Festival adds special lantern magic
- 31°C cooler than peak summer
Cons
- **250mm rain across 12 days**
- **Hoi An flooding becomes likely**
- Cham Islands tours mostly canceled
- Storm risk from typhoons
September (Monsoon Begins) Events & Festivals
- Vietnam National Day Sep 2 (long weekend)
- Mid-Autumn Festival (varies, often late Sep)
- Korean Chuseok holiday (Sep 25 in 2026)
Hoi An in September (Monsoon Begins) — Full Picture
Monsoon begins in earnest — 250mm rain + Hoi An flood risk. Hotels drop 30-50%. Korean Chuseok creates a brief travel window.
What to Wear & What to Pack
Hot + heavy rain — light long sleeves + waterproof everything.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
30°C
23°C
4.3/mo
Summer (Jun·Jul·Aug)
33.7°C
25.3°C
8.7/mo
Autumn (Sep·Oct·Nov)
Current28.3°C
22.3°C
13.3/mo
Winter (Dec·Jan·Feb)
25.3°C
19.7°C
7.7/mo
Hoi An Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 25° | 19° | 8d·100mm | 5h | 82% | 6 | Moderate | Shoulder | |
| 26° | 20° | 4d·30mm | 6h | 80% | 7 | Busy | Peak | |
| March (Peak Dry Season) (Best) | 28° | 21° | 4d·25mm | 7h | 80% | 8 | Busy | Peak |
| 30° | 23° | 4d·30mm | 8h | 80% | 10 | Very busy | Peak | |
| 32° | 25° | 5d·50mm | 8h | 80% | 11 | Very busy | Peak | |
| 34° | 26° | 7d·80mm | 8h | 78% | 11 | Very busy | Peak | |
| 34° | 25° | 8d·90mm | 8h | 78% | 11 | Very busy | Peak | |
| 33° | 25° | 11d·130mm | 7h | 80% | 10 | Busy | Shoulder | |
| 31° | 24° | 12d·250mm | 6h | 82% | 8 | Quiet | Low season | |
| 28° | 22° | 15d·530mm | 5h | 85% | 6 | Quiet | Low season | |
| 26° | 21° | 13d·360mm | 5h | 84% | 6 | Quiet | Low season | |
| 25° | 20° | 11d·220mm | 5h | 82% | 5 | Moderate | Shoulder |
View Other Months
Hoi An September (Monsoon Begins) Hotel Picks
Frequently Asked Questions
Is September (Monsoon Begins) a good time to visit Hoi An?
Hoi An in September (Monsoon Begins) is moderate. Tourist crowds are quiet and flight/hotel prices are low season.
What's the average temperature in Hoi An in September (Monsoon Begins)?
Hoi An September (Monsoon Begins) averages a high of 31°C and a low of 24°C.
Does it rain much in Hoi An in September (Monsoon Begins)?
Hoi An September (Monsoon Begins) averages 250mm of rainfall over about 12 rainy days.
What should I wear in Hoi An in September (Monsoon Begins)?
Hot + heavy rain — light long sleeves + waterproof everything.
What time are sunrise and sunset in Hoi An in September (Monsoon Begins)?
Hoi An September (Monsoon Begins) sunrise is 05:45 and sunset is 17:55, with 12h 10min of daylight.
What's the air quality like in Hoi An in September (Monsoon Begins)?
Hoi An September (Monsoon Begins) air quality (AQI) averages 42, rated Good. PM2.5 averages 15μg/m³.
What activities are recommended in Hoi An in September (Monsoon Begins)?
In September (Monsoon Begins), Hoi An is great for Old Town between rain, Mid-Autumn Lantern Festival, Tailors (indoor).
Is September (Monsoon Begins) peak season in Hoi An?
Hoi An September (Monsoon Begins) crowds are quiet and prices are low season. You can travel relatively comfortably without long queues.
Best Months to Visit Hoi An
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.