yearsofweather

Hoi An in September:
seriously hot, frequent rain

Hoi An, Vietnam · Records from 2006 to 2025. Not a forecast.

Mean high33°Hottest day 37.2° (2024)
Mean low25°Coldest night 22.6° (2012)
Rain days13 days4-18 by year
Rainfall404mmDaylight 12.4 → 12.0 h
Hoi An's 12 months iBest: January to March
Trip types Beach Finewarm sea, frequent rain and storm riskSightseeing on foot Poorhot, frequent rain, muggy and storm risk
Humidity82%30 muggy days
Clear days3 days19 overcast days
Mean wind8 km/hRarely windy
Sea temperature30.1°29.6-30.8° by year (last 6)
Sunrise / sunset (15th)05:35 / 17:49Daylight 12.4 → 12.0 h

Hoi An in September

The wet season starts and rainy days climb noticeably. Typhoon and big-wave risk rises and flood risk reaches a moderate level, so if the river swells water can reach the Old Town edges first. Check your hotel's location in advance.

Days averaged 33°C and nights 25°C. Midday was for air conditioning, a cold drink or a long lunch out of the sun. Rain fell on 13 days of the month on average. The average is 13, but individual years ran from 4 (2017) to 18 (2011).

With 27 days above 30°C on average, most of the month felt like high summer. Each rainy day brought about 32 mm, closer to downpours than drizzle.

Typhoons i

10 of the last 20 years had a tropical storm pass within 300 km this month.

  • Noru (2022), 9 km away typhoon strength
  • Noul (2020), 47 km away tropical storm
  • Ketsana (2009), 67 km away typhoon strength
1 2 3 4 5 6 27 38 109 1010 411 112

Date by date i

‹ August September 2027 October ›
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
1-4rain on 34% of days34° 25°
5-11rain on 40% of days33° 25°
12-18rain on 44% of days32° 25°
19-25rain on 46% of days32° 25°
26-30rain on 43% of days32° 24°

0-5/206-8/209-11/2012-20/20

1-4rain on 34% of days34° 25°
5-11rain on 40% of days33° 25°
12-18rain on 44% of days32° 25°
19-25rain on 46% of days32° 25°
26-30rain on 43% of days32° 24°
Tap another date to change

20064mm
2007none
200810mm
2009none
2010none
201111mm
201226mm
201327mm
2014none
2015186mm
2016none
2017118mm
20182mm
2019none
2020none
20214mm
2022none
202359mm
202430mm
2025none
Holidays in September (2027)
  • September 2 to September 5 National Day break, proposed 4-day plan *
  • September 6 Labor Day

* Provisional: not yet officially announced.

1 Local public holiday or break (busier, pricier)1 US holidays (flights fill up)

Day by day temperature i

23°28°34°39° 1815222930

Mean high Mean low Coldest to warmest high in 20 years

Your trip dates, the past 20 years

Trip dates ~

You can also click two dates on the axis. Hover a cell to see that day's rain.
Trip rain days Month rain days
2006
2 d 13 d
2007
4 d 13 d
2008
4 d 17 d
2009
5 d 17 d
2010
1 d 8 d
2011
7 d 18 d
2012
1 d 13 d
2013
4 d 18 d
2014
0 d 6 d
2015
2 d 6 d
2016
5 d 16 d
2017
1 d 4 d
2018
2 d 7 d
2019
1 d 13 d
2020
1 d 6 d
2021
5 d 17 d
2022
4 d 15 d
2023
5 d 16 d
2024
1 d 15 d
2025
1 d 14 d
Years with rain
Tap a date to start, tap another to end. Each cell is that date in one year.
'06'07'08'09'10'11'12'13'14'15'16'17'18'19'20'21'22'23'24'25
of 20
8
5
6
8
8
8
8
4
9
10
9
10
10
11
8
7
8
8
8
8
9
11
8
11
9
8
9
8
9
9
Rain days on trip
24451714025121154511

No rain1-9 mm10 mm or more Dates outside your trip are dimmed.

One row per year, one cell per day. 2017 had 4 rain days, 2011 had 18.

Hoi An through the year

MonthHighLowRain daysRainfallSea
JanuaryGood 25°19°9 days85mm 24°
FebruaryGood 26°20°4 days24mm 23°
MarchGood 29°22°3 days27mm 24°
April 31°24°4 days64mm 26°
May 34°26°4 days86mm 28°
June 35°27°5 days61mm 30°
July 35°26°8 days105mm 30°
August 35°26°9 days142mm 30°
September 33°25°13 days404mm 30°
October 30°24°18 days760mm 29°
November 28°23°17 days460mm 27°
December 26°21°15 days246mm 26°

Common questions

Does it rain a lot in Hoi An in September?

Over the past 20 years September averaged 13 rain days (1 mm or more) out of 30. Individual years ran from 4 in the driest to 18 in the wettest.

What should I wear in Hoi An in September?

Days averaged 33°C and nights 25°C. Pack an umbrella, sandals that can get wet, T-shirts, sunscreen plus a hat, a swimsuit, and insect repellent.

Can you swim in Hoi An in September?

Sea surface temperature averaged 30.1°C in September, warm enough to stay in for a long swim. Year to year it ranged 29.6-30.8°C. Check local flags for waves and jellyfish on the day.

Is September a good time to visit Hoi An?

On warmth and rain days alone, Hoi An's easiest months were January to March. September ranked 12 of 12.

Is Hoi An humid in September?

Mean relative humidity was 82%, with about 30 muggy days (dew point of 20°C or more) in the month.