Vientiane weather in August
August in Vientiane: sweltering, soaked, with clean air — not the time — 26 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#12 of 12 months in Vientiane · #1309 of 1413 destinations to visit in August · comfort 38/100 (tier F)
- Days
- 32°C
- Nights
- 25°C
- Wet days
- 26
- Sun
- 7.2 h
- Humidity
- 86%
- Daylight
- 13 h

Traveller notes on Vientiane in August
Notes from nearby Vang Vieng (108 km away)
Vientiane doesn't have its own notes for August yet — these are about Vang Vieng, close enough to share the season.
Vang Vieng-forum threads on an August visit describe river conditions as genuinely variable week to week, posters warning tubing can swing between manageable and hazardous depending on recent rain. Regulars call one August notably severe, several posters recalling flooding that halted tubing entirely for weeks that year. Posters call a fast, high river the more typical August experience, several regulars naming a roughly ninety-minute float with no rock-bumping since the water sits well above normal levels. Regulars call tubing on an actively rainy day genuinely worth skipping, several threads warning cold water and poor visibility make conditions considerably less enjoyable and less safe. Posters recommend checking river conditions with an operator before heading out, several regulars calling this standard given how quickly August rain can change things. The record: 29C days, 23.3C nights, an extraordinarily high 547.7mm across nearly 30 days and 92 percent humidity.
Other months in Vientiane
Regulars are specific this month marks the real peak of the region's burning-season haze, crop fires further north sending smoke that gets trapped in valleys under high pressure or cleared out entirely when a low pressure system moves through - genuinely impossible to predict on any given day. Our row backs that hot, genuinely hazy read, 34.1C reading as a scorching 38C, over 21.4C nights, with rain light at 29.1mm across 5.2 days and humidity at 61 percent. Regulars are consistent the rains due to arrive the following month are what actually clears the particulates from the air, so this remains the least favorable month for anyone sensitive to air quality. The record: 10.7 hours of sun, an 11.1 kph wind and AQI 96.
November opens the cool dry season here, which runs to about February, and the board's framing of it is careful: cool by comparison rather than cool in itself. This city gets described as hot in the way Bangkok is hot, and our row agrees - 32.2C reading as 36C at 70.3 percent humidity. What has actually changed is the night, which falls to 20.7C and cools off properly, and the rain, which has stopped: 23.8mm across 3.8 days, after a monsoon that runs through October. The wind is almost nothing at 9.2 kph, so shade does the work that a breeze would do elsewhere. The record: 9.5 hours of sun and AQI 56.
Vientiane-forum threads asking if March-April heat is actually bearable are candid that this is the hottest stretch of the Laotian year, daytime highs regularly in the mid-30s Celsius and climbing higher some afternoons, with humidity building steadily as the month goes on. Posters describe the heat as wet and sauna-like rather than a dry desert heat, physically draining in a way that catches some visitors off guard. Regulars who've pushed through anyway say it's doable with the right pace - take it easy, stay hydrated, treat the hottest hours as downtime. April also carries the region's burning-season haze, another reason posters steer flexible-date visitors toward November through February instead. The one genuine reward: Lao New Year's water festival lands this month, a celebration built around cooling off. The record: a scorching 36C by day feeling like a punishing 41C, 23.8C nights, 47mm across 8.5 days, 60 percent humidity and an unhealthy 110 AQI.
February in Vientiane is pleasant with some genuinely warm days, and regulars point out it never really gets cold here - our row gives 31.4C by day and 18.1C at night, at 61 percent humidity with 21.9mm of rain across 1.7 days. The month's real question in Laos is smoke, and the answer is geographic: the slash-and-burn fires are concentrated from about halfway between Vang Vieng and Luang Prabang northwards, so Vientiane in the south is largely spared while Luang Prabang is not. The burning starts around the end of February and how bad any given day gets depends on how much is alight at once and which way the breeze runs. Our row carries AQI 75. The record: feels-like 34C, 10.4 hours of sun.
Add your own note from Vientiane's card on the map.
Vientiane climate normals — August
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Vientiane in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 4 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Vientiane's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherVientiane's weather peaks December–February.
Best weatherFair weatherToughest weather
What's on in Vientiane in August
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Southwest monsoon
15 May – 15 Oct · usuallyThe rain clears the smoke out and the Mekong comes up from a sandbank to a real river. It falls hard in the late afternoon rather than all day.
- Season
Wet season
MonsoonRisk26 rainy days and about 396 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Vientiane — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Vientiane?
Vientiane in August — FAQ
- Is August a good time to visit Vientiane?
- August in Vientiane: sweltering, soaked, with clean air — not the time — 26 rainy days. It ranks #12 of 12 months for Vientiane on SeasonMap's comfort score (38/100).
- What is the weather like in Vientiane in August?
- In August, Vientiane averages a daily high of 32.4°C and a low of 24.7°C, with about 396.3 mm of rain over roughly 25.6 rainy days.
- What is the air quality in Vientiane in August?
- Vientiane has a mean US Air Quality Index of about 45 in August.
Within 300 km: Luang Prabang's Dawn alms round etiquette on 1 Jan – 31 Dec.