Hanoi in September

In September, Hanoi averages 31°C (88°F) during the day and 24°C (75°F) at night, with around 13 days of rain (230 mm total).

Off-peak

Conditions are warm and beach-friendly. Plan for unsettled weather and bring rain gear.

It's peak typhoon season in Hanoi during September. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

31°C
Avg high
24°C
Avg low
13
Rain days
230 mm
Rainfall

How September compares to the rest of the year in Hanoi

5th
warmest month of the 12
7th
wettest month of the 12
14%
of yearly rainfall falls in September
12 h 17 min
daylight on the 15th

September is in the middle of the year for warmth in Hanoi (5th of 12) and moderately rainy compared to the rest of the year (7th of 12). Daytime temperature runs 4°C above the annual average (28°C). September runs 1°C cooler than August (32°C) and cools 2°C in October (29°C).

September sunrise & sunset in Hanoi

🌅
Sunrise (15th)
5:43 AM
🌇
Sunset (15th)
6:00 PM
Day length
12 h 17 min

Times shown for Hanoi local time (Asia/Ho_Chi_Minh), calculated for the 15th of September. They shift by a few minutes day to day across the month.

Photography light in Hanoi — September

Golden-hour and blue-hour windows for the 15th of September, in Hanoi's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:43 AM – 5:23 AM
🌄 Golden hour (AM)
5:23 AM – 6:23 AM
🌇 Golden hour (PM)
5:20 PM – 6:20 PM
🌆 Blue hour (PM)
6:20 PM – 7:00 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Hanoi.

📅 When to book — Hanoi in September

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (Off-peak) and Hanoi's popularity.

✈ Flights — lead time
3-6 weeks
Cheapest flights of the year. Last-minute deals are real if you can be flexible. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
2-4 weeks
Last-minute bookings work fine. Some seasonal properties close — call ahead if it's a small boutique or beach resort.

Crowds & pricing — September in Hanoi

Off-peak

This is off-peak for Hanoi — the lowest prices of the year and the fewest crowds, but with real trade-offs: some restaurants, hotels, and beach businesses may close for the season; weather conditions can make outdoor activities unpredictable; and a handful of seasonal sights run reduced hours or close entirely. Great if you prefer a quiet local rhythm and don't mind the climate giving you reasons to choose indoor activities.

Why this tier: peak hazard season (1 active)

Sun & mosquito risk — September in Hanoi

☀️ UV Index (noon, 15th)
12.1
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Hanoi in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 20°C / 68°F 14°C / 57°F 20 mm 8 0
February 21°C / 70°F 15°C / 59°F 30 mm 12 0
March 23°C / 73°F 18°C / 64°F 45 mm 15 0
April 28°C / 82°F 21°C / 70°F 95 mm 13 0
May 32°C / 90°F 24°C / 75°F 195 mm 14 0
June 33°C / 91°F 26°C / 79°F 240 mm 14 0
July 33°C / 91°F 26°C / 79°F 290 mm 15 0
August 32°C / 90°F 26°C / 79°F 320 mm 16 0
September 31°C / 88°F 24°C / 75°F 230 mm 13 0
October 29°C / 84°F 22°C / 72°F 130 mm 9 0
November 26°C / 79°F 18°C / 64°F 45 mm 6 0
December 22°C / 72°F 15°C / 59°F 25 mm 6 0

Other cities with similar September weather

🌍 See the full ranked list of climate twins for Hanoi in September →

Frequently asked questions

How hot is Hanoi in September?

In September, Hanoi averages a high of 31°C (88°F) and a low of 24°C (75°F) — generally hot.

Does it rain a lot in Hanoi in September?

September can be fairly wet in Hanoi, with about 13 rainy days on average.

Is September a good time to visit Hanoi?

September is hot. It suits travelers who are comfortable with hot weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Hanoi in September?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full September packing list for Hanoi for a complete, climate-based checklist.

Open Hanoi on the interactive map

Check the live 10-day forecast and sunrise/sunset.