Monthly weather averages & travel planning

Asia › 🇻🇳 Vietnam › Nha Trang
Updated: March 2026
September is a avoid time to visit Nha Trang (3/10). Average highs of 30°C and 4 sunshine hours daily make conditions workable, though not exceptional. September suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 12 potential rain days. October offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Nha Trang's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.
Step off the plane in Nha Trang in September and the air meets you at around 30°C, carrying the kind of warmth that makes you reach for sunglasses before your bag is off the belt. By the time evening arrives and temperatures settle near 23°C, the city takes on a different character entirely. With 4 hours of daylight sun on offer, September gives you the raw material for a genuinely memorable trip.
30°C
86°F
Avg High
23°C
73°F
Avg Low
12 days
140 mm total
Rain Days
4h
per day avg
Sunshine
82%
Humid
Humidity
The 7°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. At 82% humidity, the 30°C daytime high feels 2-4°C warmer in practice: quick-dry fabrics and shade-seeking between noon and 3pm are the sensible response. UV index averages 6 this month, classed as moderate. Sunscreen is a sensible precaution for extended outdoor time, particularly at midday. Wind averages 15 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 86°F average high, 73°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for Nha Trang in September means dressing for 30°C days and 23°C evenings. A lightweight linen or cotton shirt with loose-fit trousers or a sundress handles the 30°C daytime heat. Evening temperatures settle at 23°C, a modest 7°C drop that a light cardigan or denim jacket covers. For footwear, breathable walking sandals work for casual exploration, but closed-toe trainers are better for uneven surfaces in the historic centre. A compact foldable umbrella weighs almost nothing and earns its keep across 12 potential rainy days. For temple and religious site visits, carry a lightweight scarf or sarong to cover shoulders and knees, required at most major sites across the region. At 82% average humidity, quick-dry synthetic or bamboo fabrics dry overnight and stay comfortable longer than cotton.
Local tip: Loose-weave linen and moisture-wicking fabrics are the practical choice in Nha Trang's heat and humidity. Many shopping centres run air conditioning at near-arctic levels, so a thin layer in your bag prevents discomfort indoors.
September has no major festivals or public holidays in Nha Trang, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
Based on 30°C average highs and 12 rainy days
Nha Trang's September climate is governed by the Inter-Tropical Convergence Zone (ITCZ), which draws moisture-laden trade winds across the region, producing the characteristic wet season rainfall of steamy tropical cities. Daytime heat peaks around 30°C, moderated slightly by afternoon convective showers. Overnight temperatures remain warm at 23°C because the humid air retains heat effectively. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Nha Trang in September
September ranks 7th sunniest of the year in Nha Trang, with an average 4 daily sunshine hours. The driest months are December, January, and November. May is the hottest month (32°C avg high); January is the coolest (28°C). From here, temperatures fall 1°C into October. Compared to last month (August: 31°C high, 15 rain days), September is cooler and drier. September sits in the middle of the annual sunshine ranking for Nha Trang, offering a reasonable balance of good weather and manageable crowds.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 28°C | 21°C | 7 | 1h | View |
| February | 29°C | 22°C | 9 | 3h | View |
| March | 30°C | 23°C | 12 | 4h | View |
| April | 31°C | 24°C | 15 | 6h | View |
| May | 32°C | 25°C | 17 | 7h | View |
| June | 32°C | 25°C | 18 | 7h | View |
| July | 32°C | 25°C | 17 | 7h | View |
| August | 31°C | 24°C | 15 | 6h | View |
| September | 30°C | 23°C | 12 | 4h | View |
| October | 29°C | 22°C | 9 | 3h | View |
| November | 28°C | 21°C | 7 | 1h | View |
| December | 28°C | 21°C | 6 | 1h | View |
January
7 rain days, 1h sun
February
9 rain days, 3h sun
March
12 rain days, 4h sun
April
15 rain days, 6h sun
May
17 rain days, 7h sun
June
18 rain days, 7h sun
July
17 rain days, 7h sun
August
15 rain days, 6h sun
September
12 rain days, 4h sun
October
9 rain days, 3h sun
November
7 rain days, 1h sun
December
6 rain days, 1h sun
Cities within 500 km with comparable weather conditions
Data Sources for Nha Trang
Climate normals represent 30-year averages (1991-2020). Individual years may vary.