Bangkok Weather in September
Thailand · Tropical Savanna climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Bangkok sees average temperatures ranging from a low of 25.1°C (77.2°F) to a high of 30.9°C (87.6°F), with a mean of 27.5°C (81.5°F). Compared to the annual average of 28.1°C (82.6°F), this month is 0.6°C cooler than the yearly norm. Precipitation averages 336.3mm, making it approximately 195.0mm wetter than the monthly average of 141.0mm. This is the wettest month of the year, with 336.3mm of precipitation and around 29.8 rainy days. The city receives an average of 7.6 hours of sunshine per day during September, with relative humidity averaging 84.0%. Wind speeds reach an average maximum of 14.3 km/h. For travelers, this month offers a temperature experience in Bangkok, with wetter-than-average conditions compared to the rest of the year.
Bangkok taught me that 'too hot' is a real concept. I arrived in April thinking I could handle it — 36°C with 70% humidity is genuinely dangerous if you're not acclimated. Pack moisture-wicking everything, plan indoor activities for 11am-3pm, and embrace the night markets. November-February is the survival window. The data backs this up: those months drop to a manageable 30°C with lower humidity and almost no rain.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 28.1°C (82.6°F) | 27.5°C (81.5°F) | 26.9°C (80.4°F) |
| Rainfall | 216.9mm | 336.3mm | 289.9mm |
| Sunshine | 8.2 hrs | 7.6 hrs | 8.3 hrs |
| Humidity | 81.0% | 84.0% | 83.1% |
| Wind | 16.1 km/h | 14.3 km/h | 12.7 km/h |
| Rainy Days | 29.8 | 29.8 | 25.8 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Bangkok in September, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Bangkok in September?
The average temperature in Bangkok during September ranges from 25.1°C (77.2°F) to 30.9°C (87.6°F), with a mean of 27.5°C (81.5°F).
How much does it rain in Bangkok in September?
Bangkok receives an average of 336.3mm of precipitation in September, spread across approximately 29.8 rainy days. This is the wettest month of the year.
What should I pack for Bangkok in September?
Based on September weather data, pack lightweight, breathable clothing, sunscreen, and a hat. Rain gear is essential — this month averages 336.3mm of precipitation.
Is September a good time to visit Bangkok?
September is a month with challenging conditions. Plan activities carefully and stay hydrated.
Other Months for Bangkok
Cities with Similar September Climate (Tropical Savanna)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 13.76°, 100.5°. Timezone: Asia/Bangkok. Last updated: 2026-07-30.