September · Thailand
Best time to visit Chiang Rai in September Weather, crowds & prices
Weather in Chiang Rai in September
Average temperature 26°C, 245 mm of rain, about 15 days with 6+ hours of sunshine and 83% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
3.6/10
Ranked #12 of 12 months
- Avg temp
- 26°C
- Rainfall
- 245 mm
- Humidity
- 83%
- Days with 6h+ sun
- 15
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Chiang Rai scores 3.6/10 for sightseeing and cultural travel - ranked #12 of 12. Expect around 26°C, 245 mm of rain, and roughly 15 days with 6+ hours of sunshine this month.
Chiang Rai's white temple, golden clock tower and hill villages fill Thailand's far north.
September in Chiang Rai — the hardest end of the year
Days in September average 26°C (79°F) and humidity near 83% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 245 mm: only about 15 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 3.6/10 on the same scale — 12th of 12 months, versus 9.8/10 for the best month here.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella.
Expect low-season pricing, and crowds are light for this destination.
If your dates are flexible, February is materially better in Chiang Rai — 6.2 points higher on the same scale.
Frequently asked
- What is the weather like in Chiang Rai in September?
- In September, Chiang Rai averages 26°C, 245 mm of rain, and about 15 days with 6+ hours of sunshine. Its climate-comfort score is 3.6/10.
- Is September a good time to visit Chiang Rai?
- September earns a 3.6/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Chiang Rai in September?
- Expect about 245 mm of rain in September. Average humidity is 83% and there are about 15 days with 6+ hours of sunshine.
Curated in Chiang Rai
Tickets & experiences
Things to do in Chiang Rai
Chiang Rai, Thailand. Live activities and tours from GetYourGuide, matched to this destination.