| Month | Mean, °C | Mean max, °C | Mean min, °C | Rain, mm | Rain days | Humidity, % | Sunshine, h |
|---|---|---|---|---|---|---|---|
| January | 27.4 | 32.7 | 23.4 | 23.6 | 2.6 | 68 | 216.0 |
| February | 28.6 | 33.7 | 24.8 | 21.4 | 2.5 | 71 | 215.8 |
| March | 29.7 | 34.7 | 26.4 | 51.0 | 4.1 | 73 | 234.2 |
| April | 30.7 | 35.7 | 27.2 | 93.3 | 6.5 | 72 | 226.6 |
| May | 30.3 | 35.1 | 26.9 | 216.8 | 15.0 | 74 | 196.2 |
| June | 29.7 | 34.1 | 26.4 | 198.5 | 16.4 | 75 | 158.4 |
| July | 29.2 | 33.5 | 26.1 | 189.7 | 17.2 | 76 | 140.7 |
| August | 29.0 | 33.3 | 25.9 | 227.1 | 19.1 | 76 | 128.9 |
| September | 28.6 | 33.2 | 25.4 | 335.9 | 21.4 | 79 | 129.6 |
| October | 28.4 | 33.0 | 25.2 | 288.7 | 17.0 | 78 | 157.5 |
| November | 28.4 | 33.1 | 24.7 | 44.6 | 5.0 | 69 | 194.8 |
| December | 27.3 | 32.3 | 23.2 | 11.6 | 1.5 | 66 | 213.5 |
| Year | 28.9 | 33.7 | 25.5 | 1,702.2 | 128.3 | 73 | 2,212.2 |
The table above is a climate normal: averages over 30 years, not a forecast for any given year. A single year can be drier or wetter. For planning a trip, the normal is more useful than last year’s weather: it shows what to expect in a typical month.
What the numbers show
Two seasons by rain. From November to February 11.6-44.6 mm falls each month, from May to October 189.7-335.9 mm. In September it rains on 21 days out of 30 on average. Mind the method: TMD counts a rain day whenever at least 0.1 mm falls, so short showers count too.
Heat peaks before the rain. March and April are the hottest months, with highs of 34.7 and 35.7 °C and nights of 26.4 and 27.2 °C. From August to October highs are about 33 °C.
The cool season is mild. December and January have means of 27.3 and 27.4 °C and nights of 23.2 and 23.4 °C, while daytime highs stay above 32 °C. Humidity is lowest then too: 66% in December.
Sunshine drops in the rainy months. The station records 2,212.2 hours a year: 234.2 in March and 128.9 in August, the dullest month.
Bangkok weather by season
Our grouping of the monthly TMD figures in the table above (Bangkok Metropolis station, 1991-2020).
| Period | Months | Mean max, °C | Rain a month, mm | Rain days a month | Humidity, % |
|---|---|---|---|---|---|
| Dry, least hot | November-February | 32.3-33.7 | 11.6-44.6 | 1.5-5.0 | 66-71 |
| Hottest | March-April | 34.7-35.7 | 51.0-93.3 | 4.1-6.5 | 72-73 |
| Rainy | May-October | 33.0-35.1 | 189.7-335.9 | 15.0-21.4 | 74-79 |
For the same month in other parts of the country, see Thailand in November and Thailand in December.
Seasons according to TMD
TMD describes three seasons for the country as a whole:
| Season | Months per TMD | What happens |
|---|---|---|
| Cool | October-February | north-east monsoon, generally cool and dry weather |
| Hot | February-May | transition, variable winds, hot and dry |
| Rainy | May-October | south-west monsoon brings moisture from the ocean, heaviest rain on windward coasts |
Bangkok’s figures follow this pattern closely. For the central plain TMD adds that the low-lying land floods easily in the rainy season, and that the cool season is not very cold and the hot season not extremely hot because the sea is close.
City and airports: three stations
The TMD report has normals for the city station and both airports. For Suvarnabhumi (BKK) the report gives a normal for 2008-2020, a shorter period than for the other two.
| Annual figure | Bangkok Metropolis (48 455) | Don Muang Airport (48 456) | Suvarnabhumi Airport (48 429) |
|---|---|---|---|
| Period | 1991-2020 | 1991-2020 | 2008-2020 |
| Mean temperature | 28.9 °C | 28.9 °C | 28.7 °C |
| Mean maximum | 33.7 °C | 33.5 °C | 33.1 °C |
| Mean minimum | 25.5 °C | 25.3 °C | 25.3 °C |
| Rainfall | 1,702.2 mm | 1,474.3 mm | 1,150.4 mm |
| Rain days | 128.3 | 119.2 | 138.9 |
| Humidity | 73% | 72% | 68% |
| Wettest month | September, 335.9 mm | September, 300.0 mm | September, 220.3 mm |
| Driest month | December, 11.6 mm | February, 11.5 mm | December, 6.3 mm |
| Sunshine | 2,212.2 h | no observations | no observations |
Mean temperatures at the three stations differ by no more than 0.6 °C, and all three have their wettest month in September. Rainfall differs more: 1,702 mm in the city, 1,474 mm at Don Muang and 1,150 mm at Suvarnabhumi. Part of the Suvarnabhumi gap may come from the different period, so compare it with care. Both airports are about 23-24 km from the city station in a straight line (our calculation from the station coordinates in the TMD report).
At Don Muang the report gives the thermometer height as 17.5 m above ground and the rain gauge as 16.5 m, against 1.25 m and 0.87 m at the city station. Keep that in mind when comparing the two.
Today’s forecast from TMD
The normals show a typical month, not the coming week. For the next seven days use the TMD 7-day forecast: Bangkok has its own section there, Bangkok Metropolitan, with daily highs and lows and wind.
Method and limits
- Source: Thai Meteorological Department report Climatological Data of Thailand for 30 Year Period (1991-2020), printed pages 51 (Bangkok Metropolis), 53 (Don Muang Airport) and 47 (Suvarnabhumi Airport); Phuket figures from page 82. The report is published on a TMD subdomain.
- Period: 30 years, 1991-2020, the latest 30-year period for which TMD has published normals; 2008-2020 for Suvarnabhumi
- How we compiled it: figures copied from the report without recalculation. We checked monthly totals of rain, rain days and sunshine against the annual values for all three stations and found no discrepancies.
- Rain day: at least 0.1 mm in 24 hours, counted from 07:00 to 07:00
- What is missing: air quality and flooding by district. The report covers weather observations only.
- Next update: when TMD publishes new normals or at our April 2027 review
Onward trips from Bangkok: to Koh Samui, to Hua Hin, to Phuket. Weather at the destination: Hua Hin, Koh Samui, Phuket.
FAQ
What is the best month for weather in Bangkok?
By the TMD normals, December: the driest month (11.6 mm, 1.5 rain days), the least humid (66%) and the coolest, with a mean of 27.3 °C and nights of 23.2 °C. January and February are also dry, with 21-24 mm and about 2.5 rain days. Highs stay above 32 °C even then.
When is the rainy season in Bangkok?
May to October: TMD's 1991-2020 normals give 190-336 mm a month and 15-21 rain days. September is the wettest month (335.9 mm), October follows (288.7 mm). TMD notes that the central plain, where Bangkok lies, floods easily in the rainy season.
When is the dry season in Bangkok?
November to February: 11.6-44.6 mm a month and 1.5-5.0 rain days. March and April are still fairly dry (51 and 93 mm) but are the hottest months. Rain days jump to 15 in May.
What is the hottest month in Bangkok?
April: a mean of 30.7 °C, an average high of 35.7 °C and nights of 27.2 °C. The highest temperature at the station in 1991-2020 was 40.1 °C, in March; April and May reached 40.0 °C.
What is the weather like in Bangkok in November?
November is when the dry season starts: rainfall drops from 288.7 mm in October to 44.6 mm, with 5.0 rain days. Highs are still 33.1 °C, but humidity falls to 69%.
What is the weather like in Bangkok in December?
December is the driest and coolest month: 11.6 mm of rain, 1.5 rain days, a mean of 27.3 °C and nights of 23.2 °C. Days are still hot, with highs of 32.3 °C. The lowest temperature at the station in 1991-2020, 13.2 °C, was recorded in December.
Is Bangkok hotter than Phuket?
In the daytime, yes: the average high over the year is 33.7 °C in Bangkok and 32.8 °C in Phuket town, and in April 35.7 °C against 34.2 °C. Nights in the cool season are cooler in Bangkok: 23.2 °C in December against 25.0 °C. Bangkok gets less rain: 1,702.2 mm a year against 2,271.5 mm.
Does it rain all day in Bangkok in the rainy season?
The normals cannot tell you that. TMD counts any day with at least 0.1 mm as a rain day, so the 21.4 rain days in September include short showers. The report does not publish how many hours it rains, but it does count thunderstorm days: 10.6 in September.
Sources
- Thai Meteorological Department. Climatological Data of Thailand for 30 Year Period (1991-2020), printed pages 51 (Bangkok Metropolis), 47 (Suvarnabhumi Airport), 53 (Don Muang Airport) and 82 (Phuket)
- Thai Meteorological Department. Natural hazards in Thailand: climate and seasons, pages 2-4 (Thai)
- Thai Meteorological Department. 7-day weather forecast (regions)
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