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Climate · Vientiane

Vientiane in September

Hot and wet, as the days shorten.

Typical weather, averaged over 30 years

September in Vientiane is hot: highs near 89°F, lows near 75°F. Rain falls on about six days a week, less often as the month goes on, and the days shorten by 22 minutes from the first week to the last.September in Vientiane is hot: highs near 32°C, lows near 24°C. Rain falls on about six days a week, less often as the month goes on, and the days shorten by 22 minutes from the first week to the last.

High
89°F32°Caverage
Low
75°F24°Caverage
Wet days
6a week · 84% of days
Daylight
12h 12mon average

Is September a good time to visit Vientiane?

September sits outside Vientiane's best months, which run from December to January. Expect hot days and rain on about six days a week.

How we judge it: every month is scored on how close its typical high comes to the range from 70°F to 80°F, how mild its nights are, and how rarely it rains. The best months are the run of months that scores best.How we judge it: every month is scored on how close its typical high comes to the range from 21°C to 27°C, how mild its nights are, and how rarely it rains. The best months are the run of months that scores best.

How September sits in the year

week by week

Temperature

Highs near 89°F in September, against 84°F to 96°F through the year.Highs near 32°C in September, against 29°C to 36°C through the year.

Chance of a wet day

84% of days in September, against 4% to 89% through the year.

Cloud cover

79% cover in September, against 41% to 84% through the year.

Daylight

12h 12m in September, against 11h 04m to 13h 11m through the year.

Week by week, lightly smoothed, with September shaded. The olive line marks the best months. Hover or tap a week for its figures.

Either side

  1. August89°32°low 76°low 24°6 wet days a weekRain on about six days a week.
  2. September89°32°low 75°low 24°6 wet days a weekRain on about six days a week.
  3. October88°31°low 74°low 23°3 wet days a weekRain on about three days a week.

Where Vientiane sits, in September

Asia/Vientiane
this place
typical high in September 40°F4°C95°F35°C
Sunrise, mid-September
5:57 AMsets 6:13 PM
Above the sea
160 mlow-lying
Latitude
18.0°Nnorthern hemisphere
Nearest of ours
Luang Prabang220 km north

The land around Vientiane, shaded by its typical high in September, the planning map's own layer. Hover the map for the figure at that spot; tap it on a phone. Clock times are local, for the 15th.

Elsewhere in Laos in September

high · low · wet days
See September on the planning mapThe whole year in Vientiane

Typical weather, averaged over 30 years (1995–2024), from the 11 km grid square nearest Vientiane. Temperatures are adjusted against 66 weather stations: daytime highs read about 3.1°F cold in the source data and are raised to match.Temperatures are adjusted against 66 weather stations: daytime highs read about 1.7°C cold in the source data and are raised to match. Daylight is calculated from latitude. Charts are lightly smoothed week to week; the figures in the table are not. Source: Copernicus ERA5-Land reanalysis; cloud cover from NASA's MERRA-2 reanalysis, on a coarser grid of about 50 km. Contains modified Copernicus Climate Change Service information 2026; neither the European Commission nor ECMWF is responsible for any use of it. These are averages, not a forecast.

Daylight is calculated from latitude. Charts are lightly smoothed week to week; the figures in the table are not.

Source: Copernicus ERA5-Land reanalysis; cloud cover from NASA's MERRA-2 reanalysis, on a coarser grid of about 50 km. Contains modified Copernicus Climate Change Service information 2026; neither the European Commission nor ECMWF is responsible for any use of it. These are averages, not a forecast.