Bangkok in September
In September, Bangkok has a daily high of 32.1 °C (89.8 °F) and a daily low of 25.2 °C (77.4 °F), as 1991-2020 model estimates; figures in brackets are converted. The daily high is a model estimate, adjusted against station records. There is no data for rain: Not published: the model failed our station test in tropical cities.
Last updated : back, with ERA5-Land model estimates.
Best time to visit Bangkok: September misses our rule: days are 4.1 °C over our 28 °C (model estimates). Expect days that shorten by 22 min.
What September is like in Bangkok
- Passage migrants such as the Yellow-rumped Flycatcher and Forest Wagtail stop to feed in Suan Rot Fai, mostly in September and October. Source: thaibirding.com, Suan Rot Fai, checked .
- Every September, on Silpa Bhirasri Day, students sing "Santa Lucia" in front of his statue at Silpakorn University's Tha Phra campus. It was his favourite song. Source: The Nation (Thailand), checked .
- Every 24 September, on Prince Mahidol Day, people give money at Siriraj Hospital to treat the poor. In thanks, they get a small three-cornered flag. Source: Royal Thai Consulate-General, Hong Kong, checked .
Key figures
Weather in September, 1991-2020 model estimates
- Daily high
- 32.1 °C (89.8 °F)
- Daily low
- 25.2 °C (77.4 °F)
- Rain
- no data
- Sunshine
- no data
Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Daily high: model estimate, adjusted against station records. Licence: CC BY 4.0. Checked . How we make and test model estimates
Model estimate for the ERA5-Land grid cell at 13.7° N, 100.5° E, 6 km from the city centre point.
How we define and convert these figures
Notes. Rain: Not published: the model failed our station test in tropical cities. Sunshine: Not in our ERA5-Land estimates.
Daylight on 15 September 2026
- Sunrise
- 06:07 local time
- Sunset
- 18:19 local time
- Day length
- 12 h 13 min
Day length 1-30 September: 12 h 23 min to 12 h 01 min, -22 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high in °C, 1991-2020 model estimates. Rain: no data.
ERA5-Land model estimates 1991-2020, as above, checked .
This month against the year
| Measure | September | Rank |
|---|---|---|
| Daily high | 32.1 °C | 5th coldest |
| Daily low | 25.2 °C | 6th coldest |
| Rain | no data | no data |
| Sunshine | no data | no data |
| Day length | 12 h 13 min | 6th longest |
Equal values share a rank. How we rank months
ERA5-Land model estimates 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
| Date | Holiday |
|---|---|
| Monday | Special public holiday (One-off, for flooding. Government offices in Bangkok, Nonthaburi, Pathum Thani and Samut Prakan only) consular.mfa.go.th |
| Tuesday | Special public holiday (One-off, for flooding. Government offices in Bangkok, Nonthaburi, Pathum Thani and Samut Prakan only) consular.mfa.go.th |
Typed from the official list and re-checked, .
September 2027: no data. No government list for 2027 yet.
Source: Official public holiday list (soc.go.th), checked ; holidays Python library, checked . Library: holidays 0.105.
Same month in 8 model-estimate cities
Bangkok is warmer than 6 of our 8 model-estimate cities in September by mean daily high. How we rank cities
Closest high and low in September: Delhi (1.3 °C apart, equal), Mumbai (1.3, equal), Lisbon (6.5).
| City | Gap from Bangkok, °C | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|---|
| Bangkok (this page) | — | 32.1 | 25.2 | no data | no data |
| Delhi (closest) | 1.3 | 33.7 | 24.2 | no data | no data |
| Mumbai (closest) | 1.3 | 29.8 | 24.9 | no data | no data |
| Lisbon (closest) | 6.5 | 26.1 | 18.2 | 31.2 | no data |
| Istanbul | 7.0 | 25.2 | 18.2 | 49.0 | no data |
| Porto | 7.9 | 25.6 | 15.9 | 59.5 | no data |
| Sydney | 12.2 | 21.1 | 11.9 | 49.1 | no data |
| Melbourne | 16.0 | 17.4 | 7.9 | 67.4 | no data |
Sources (1991-2020): ERA5-Land model estimates, checked . Each city's page names its grid cell. All sources in full on Methodology.
Sources
- Attribution: Copernicus Climate Change Service (2025): ERA5 Land hourly time-series data from 1950 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/ee82e357. Accessed on the check date shown. Generated using or contains modified Copernicus Climate Change Service information 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Licence: CC BY 4.0. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
- holidays Python library, run locally. Attribution: holidays library, Vacanza team. Licence: MIT. Checked .
Official sources
- Official public holiday list (soc.go.th). Checked .
Cite this page: City by Month. "Bangkok in September: weather, daylight, holidays". https://citybymonth.com/cities/thailand/bangkok/september/. Last updated 8 November 2026.