September · Laos
Best time to visit Si Phan Don in September Weather, crowds & prices
Weather in Si Phan Don in September
Average temperature 27°C, 260 mm of rain, about 14 days with 6+ hours of sunshine and 80% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
5.2/10
Ranked #9 of 12 months
- Avg temp
- 27°C
- Rainfall
- 260 mm
- Humidity
- 80%
- Days with 6h+ sun
- 14
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Si Phan Don scores 5.2/10 for nature and wildlife travel - ranked #9 of 12. Expect around 27°C, 260 mm of rain, and roughly 14 days with 6+ hours of sunshine this month.
A tranquil archipelago of river islands on the Mekong in southern Laos, perfect during the dry season.
September in Si Phan Don — middling scores, decent value
September averages 27°C (81°F) and humidity near 80%, so the practical pattern is early mornings, a long midday break, and evenings back outside.
260 mm of rain puts this in monsoon territory — about 14 days with 6+ hours of sunshine across the whole month, and multi-day washouts are normal.
It scores 5.2/10 here, 9th of 12 months, against 9.6/10 in the destination's best month.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella, footwear you can get muddy.
Figure on low-season pricing, with crowds are light for this destination.
Flexible dates? January scores 4.4 points higher here — enough to change the trip.
Frequently asked
- What is the weather like in Si Phan Don in September?
- In September, Si Phan Don averages 27°C, 260 mm of rain, and about 14 days with 6+ hours of sunshine. Its climate-comfort score is 5.2/10.
- Is September a good time to visit Si Phan Don?
- September earns a 5.2/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Si Phan Don in September?
- Expect about 260 mm of rain in September. Average humidity is 80% and there are about 14 days with 6+ hours of sunshine.
Curated in Si Phan Don
Tickets & experiences
Things to do in Si Phan Don
Si Phan Don, Laos. Live activities and tours from GetYourGuide, matched to this destination.