Nong Khiaw weather in September

September in Nong Khiaw: sweltering, soaked, with clean air — a gamble, with 20 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Nong Khiaw🇱🇦 Laos · Northern Thailand & Laos · Trekking59
  1. 87Jan
  2. 84Feb
  3. 66Mar
  4. 49Apr
  5. 54May
  6. 56Jun
  7. 51Jul
  8. 44Aug
  9. 59Sep
  10. 72Oct
  11. 80Nov
  12. 89Dec

#7 of 12 months in Nong Khiaw · #1157 of 1413 destinations to visit in September · comfort 59/100 (tier D)

Days
30°C
Nights
23°C
Wet days
20
Sun
8.9 h
Humidity
89%
Daylight
12 h
Nong Khiaw, Laos
Photo: Mykhailo Petrushchak · Pexels

Traveller notes on Nong Khiaw in September

Nong Khiaw-forum threads on Laos weather describe September as still within the wetter monsoon stretch running roughly June through October, real flood and landslide risk part of the picture in a heavier year. Posters describe a typical late-September day as generally okay overall, a couple of afternoon thunderstorms common but most heavier rain arriving overnight rather than disrupting sightseeing. Regulars call October through February the more reliably comfortable window, lower humidity and milder temperatures the preferred stretch for river trips and cave exploring around town. Posters recommend flexible plans, a kayak trip along the Nam Ou River easily rescheduled around a passing system. Regulars call the karst scenery worth the trip even during wetter months. Posters recommend real rain gear as standing advice throughout the season. The record: 29.9C days feeling like a punishing 36C, 23.1C nights, an extraordinarily high 204mm across nearly 20 days and 89 percent humidity.
NongKhiawSeptemberRegular · September · 1 month ago · Read more on Tripadvisor ↗

Other months in Nong Khiaw

Nong Khiaw-forum threads on a February visit describe this as genuinely packed with visitors, posters naming this the peak of the dry-season travel window. Regulars call conditions here noticeably colder than Luang Prabang, several posters naming daytime highs around eighteen degrees compared with considerably warmer readings in the city, nights dropping further still. Posters call October through February genuinely the best stretch overall, several regulars naming comfortable temperatures and low humidity as reasons hiking, kayaking and cave exploring all work well. Regulars call real warm layers worth packing for February evenings, several threads naming the daytime-to-night swing more noticeable than visitors expect. Posters recommend booking accommodation ahead given how busy February gets, several regulars calling this standard for the peak of the season. The record: 27.8C days, 15.4C nights, 17.1mm across under 2 days and 71 percent humidity.
NongKhiawFebruaryRegular · February · 1 month ago · Read more on Tripadvisor ↗
Nong Khiaw-forum threads on an August visit describe rain as genuinely concentrated in early mornings, posters naming this pattern as why afternoons often clear into sunny, humid heat even during peak wet season. Regulars call June through August the wettest stretch, several posters naming four to six rainy days a week as standard here. Posters call multi-day treks genuinely discouraged in August, several regulars warning steep trails turn muddy and slippery enough to make longer hikes riskier than in drier months. Regulars call the river and karst scenery still worth the trip despite the rain, several threads naming a long-term Laos resident who prefers August over June for fewer crowds. Posters recommend real flexible plans and waterproof gear, several regulars calling this standard given how quickly conditions shift through the day. The record: 29.6C days, 23.5C nights, an extraordinarily high 344mm across over 25 days and 91 percent humidity.
NongKhiawAugustRegular · August · 1 month ago · Read more on Tripadvisor ↗
Nong Khiaw-forum threads on an April visit describe March through May as genuinely the hottest stretch of the year in Laos, posters naming this real window even though it still falls within the broader November-through-April season most guides recommend. Regulars call real heat a genuine factor for planning outdoor activities, several posters recommending early starts for hiking or riverside walks to avoid the worst midday sun. Posters call the Nam Ou river a real cooling draw regardless of exact April dates, several regulars naming boat trips and riverside stays as a way to escape the heat. Regulars call April genuinely still within the recommended season, several threads distinguishing the heat from the wetter, muddier conditions arriving later in the year. Posters recommend real sun protection and serious hydration, several regulars calling this standard advice for the hottest months here. The record: 33.2C days, 21.8C nights, 63.7mm across nearly 9 days and 71 percent humidity.
NongKhiawAprilRegular · April · 1 month ago · Read more on Tripadvisor ↗
Nong Khiaw-forum threads on a November visit describe this as genuinely just ahead of the main tourist season, posters calling it a real sweet spot for anyone wanting the area's scenery without peak crowds. Regulars call walking out from Muang Ngoi and overnighting in small villages a real independent option, several posters confirming no guide is needed for these informal riverside walks. Posters call Muang Ngoi genuinely the exception to the usual no-solo-trekking advice, several regulars recommending well-trodden paths if going without a guide. Regulars call the viewpoint trek a real standard outing, several threads naming its forty-five to sixty minute length and well-maintained trail accessible for most fitness levels. Posters recommend booking longer treks through a local operator regardless of dates, several regulars calling this standard for reaching remote villages along the Nam Ou. The record: 27.5C days, 17.9C nights, 19.1mm across over 3 days and 80 percent humidity.
NongKhiawNovemberRegular · November · 1 month ago · Read more on Tripadvisor ↗

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Nong Khiaw climate normals — September

Daytime high30°C / 86°F🔥 sweltering
Nighttime low23°C / 74°F
Feels like (high)36°C / 97°F
Rainfall204 mm / 8 in⛈ soaked
Rainy days20 days
Humidity89%💦 very humid
Dew point24°C / 75°F
Sunshine8.9 h/day
Daylight12.3 h
Wind6 km/h / 4 mph
Air quality (US AQI)30🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Nong Khiaw in September

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.

Shoulder seasonschool holidays in 3 of the markets that fill it, an ordinary month(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Nong Khiaw'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).

Fair weatherNong Khiaw's weather peaks December–February.

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Best weatherFair weatherToughest weather

Nearby, and something's on

Within 300 km of Nong Khiaw — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Nong Khiaw?

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Nong Khiaw in September — FAQ

Is September a good time to visit Nong Khiaw?
September in Nong Khiaw: sweltering, soaked, with clean air — a gamble, with 20 rainy days. It ranks #7 of 12 months for Nong Khiaw on SeasonMap's comfort score (59/100).
What is the weather like in Nong Khiaw in September?
In September, Nong Khiaw averages a daily high of 29.9°C and a low of 23.1°C, with about 203.6 mm of rain over roughly 19.8 rainy days.
What is the air quality in Nong Khiaw in September?
Nong Khiaw has a mean US Air Quality Index of about 30 in September.

Within 300 km: Luang Prabang's Dawn alms round etiquette on 1 Jan – 31 Dec, and Vientiane's Southwest monsoon around 15 May – 15 Oct.