Bangkok records about 1648mm of rain across roughly 132 wet days a year, which is a 36% chance on an average day. September is the wettest month at 344mm (21% of the annual total) and January the driest at 9mm. Local rain type: monsoon. Critical from May through October. Bangkok monsoon rain is intense but usually short-lived — carry a compact umbrella and waterproof phone pouch at all times.
Chance of rain on an average day: 36%
Rainfall climatology for Bangkok. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1648mm |
| Rain days per year | 132 |
| Odds on an average day | 36% |
| Wettest month | September — 344mm over 30 days |
| Driest month | January — 9mm over 1 days |
| Rain type | monsoon |
| Best dry window | November through February offers dry, cooler weather — the ideal Bangkok experience. |
| Worst rain window | September and October bring the heaviest monsoon rainfall with potential flooding. |
September delivers 3722% more rain than January (344mm vs 9mm). That gap is the difference between planning around showers and ignoring them.
21% of the year's rain falls in September alone, so Bangkok has a genuine wet season rather than evenly spread showers.
Bangkok rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 30 days in September against 1 in January — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 9mm | 1 | 3% | 32°C |
| February | 30mm | 3 | 10% | 32°C |
| March | 29mm | 3 | 10% | 32°C |
| April | 65mm | 6 | 20% | 33°C |
| May | 220mm | 19 | 63% | 34°C |
| June | 149mm | 13 | 43% | 35°C |
| July | 155mm | 14 | 47% | 35°C |
| August | 197mm | 17 | 57% | 35°C |
| September | 344mm | 30 | 100% | 35°C |
| October | 242mm | 21 | 70% | 34°C |
| November | 48mm | 4 | 13% | 33°C |
| December | 10mm | 1 | 3% | 32°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Bangkok we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Bangkok records rain on roughly 132 days a year — about a 36% chance on any given day — totalling around 1648mm.
September, with about 344mm over 30 rain days. That is 21% of the entire year's rainfall in a single month.
January is the driest month at 9mm across roughly 1 days. November through February offers dry, cooler weather — the ideal Bangkok experience.
Critical from May through October. Bangkok monsoon rain is intense but usually short-lived — carry a compact umbrella and waterproof phone pouch at all times.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.