Bangkok is warmest in March, averaging 38° by day and 25° at night. The wettest month is September with 336 mm, and the year brings about 1523 mm in total.
Month by month
| Month | High | Low | Rain | Sea | Daylight | Good for |
|---|---|---|---|---|---|---|
| January | 34° | 21° | 6 mm | 27° | 11.3 h | Beach weather |
| February | 36° | 23° | 25 mm | 28° | 11.5 h | Beach weather |
| March | 38° | 25° | 31 mm | 30° | 11.9 h | Very hot |
| April | 37° | 26° | 72 mm | 31° | 12.3 h | Very hot |
| May | 35° | 26° | 152 mm | 31° | 12.6 h | Mild |
| June | 33° | 25° | 144 mm | 31° | 12.8 h | Mild |
| July | 32° | 25° | 229 mm | 30° | 12.7 h | Rainy season |
| August | 32° | 24° | 229 mm | 30° | 12.5 h | Rainy season |
| September | 31° | 24° | 336 mm | 30° | 12.1 h | Rainy season |
| October | 30° | 24° | 248 mm | 30° | 11.7 h | Rainy season |
| November | 30° | 23° | 48 mm | 29° | 11.3 h | Beach weather |
| December | 30° | 20° | 3 mm | 28° | 11.2 h | Beach weather |
High and low are average daily maximum and minimum, rain is typical monthly total, sea is the average surface temperature, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER and NOAA MUR — averages, not promises.
When to go
Beach weather: January, February, November and December — highs around 33°, nights no colder than 20°, and at most 48 mm of rain in a month. The sea sits at 27–29° then.
Wet season: July, August, September and October — up to 336 mm in a single month.
Serious heat: In March and April the average high reaches 38°.