Bangkok has three seasons — cool & dry, hot, and rainy — and a fourth thing newcomers need to know about: the burning-season haze. Here's the month-by-month picture, with temperatures, rainfall, the best time to move, and what to pack.
Bangkok sits in the tropics, so it's warm to hot every single day of the year — there is no real winter. What changes is the humidity, the rain and the air. The cool, dry season (November–February) is the most comfortable and the best time to move or visit; the hot season (March–May) peaks in a sweltering April; and the rainy season (May–October) brings dramatic but usually short afternoon downpours and the year's lowest prices. Layered on top, a regional crop-burning haze pushes PM2.5 up from roughly January to April. For live rent by neighbourhood and tower, use the BAANLYY area scores and Bangkok hub.
Typical average daytime high, night-time low and monthly rainfall for Bangkok. Figures are long-term guide averages — any given year varies.
| Month | Avg high | Avg low | Rainfall | Season | What to expect |
|---|---|---|---|---|---|
| January | 33°C | 22°C | ~10 mm | Cool / dry | Peak season — warm days, cooler nights, low rain. Haze can start to build inland. |
| February | 34°C | 24°C | ~20 mm | Cool → hot | Still dry and pleasant early on; heat and PM2.5 haze ramp up by month's end. |
| March | 35°C | 26°C | ~30 mm | Hot / hazy | Heat builds and burning-season smog is often at its worst across the wider region. |
| April | 36°C | 27°C | ~70 mm | Hot (peak) | The hottest, most humid month. Songkran (Thai New Year, ~13–15 Apr) brings city-wide water fights. |
| May | 35°C | 26°C | ~190 mm | Rainy (start) | The southwest monsoon arrives; afternoon downpours break the heat but humidity stays high. |
| June | 34°C | 26°C | ~150 mm | Rainy | Short, heavy afternoon storms most days, then clear again. Still plenty of usable daylight. |
| July | 33°C | 25°C | ~160 mm | Rainy | Warm and wet with a brief mid-monsoon lull in some years. Greenery at its lushest. |
| August | 33°C | 25°C | ~190 mm | Rainy | One of the wetter months; rain is frequent but rarely all-day. Low-season prices. |
| September | 32°C | 25°C | ~320 mm | Rainy (peak) | The wettest month — heaviest rainfall and the highest risk of localised street flooding. |
| October | 32°C | 25°C | ~280 mm | Rainy (end) | Monsoon tails off; still wet and flood-prone early, drying out toward month's end. |
| November | 32°C | 23°C | ~50 mm | Cool (start) | The turn of the season — rain eases, humidity drops, skies clear. A superb month to arrive. |
| December | 31°C | 21°C | ~10 mm | Cool / dry | The most comfortable month: warm, dry, sunny days and the coolest nights of the year. |
Bangkok's best stretch and its high tourist season. 'Cool' is relative — daytime highs still sit around 31–34°C — but humidity falls, rain is rare, skies are clear and nights can dip to a genuinely pleasant 21–24°C. This is the easiest time to move, house-hunt and settle in. The trade-off is peak demand: flights, hotels and short-term rentals are at their priciest, and the best condos lease quickly.
The thermometer climbs steadily, peaking in April with highs of 35–40°C and oppressive humidity that makes it feel hotter still. Air-conditioning becomes non-negotiable and electricity bills jump. Songkran, the Thai New Year water festival around 13–15 April, turns whole districts into joyful water fights. March and early April also coincide with the worst of the regional burning-season haze (see below).
The southwest monsoon brings Bangkok's rain — but not the all-day greyness many newcomers expect. Most days deliver a heavy, dramatic downpour for an hour or two (often late afternoon), then clear up. September and October are the wettest and the months when low-lying streets can flood after a sustained storm. Upsides: lush greenery, cleaner air, fewer crowds and the lowest accommodation prices of the year.
The one weather factor that surprises new arrivals isn't heat or rain — it's air quality. From roughly January to April, agricultural crop-residue burning across Thailand and neighbouring countries combines with still, dry, hot-season air to trap fine particulate matter (PM2.5) over the city. On the worst days a grey haze settles over the skyline and the air-quality index tips into the unhealthy range, with February and March often the peak. It eases as the rains arrive and clear the air. Practical responses are simple: track a daily AQI app, run an air purifier at home (most modern condos already have or allow one), keep windows shut on bad days, and wear an N95/KN95 mask outdoors when readings spike. Anyone with asthma or young children should weigh this season when timing a move.
Humidity in Bangkok is high year-round and highest in the rainy season, which is why air-conditioning and good airflow matter when choosing a condo. During heavy monsoon downpours — especially in September and October — low-lying streets and some districts can flood for a few hours until the drains catch up. Serious, prolonged city-wide flooding (as in 2011) is rare, but it's worth asking about local drainage and whether the immediate streets are flood-prone before you commit to an area or building. Higher floors, well-managed buildings and better-drained districts all help.
For comfort, November and December are the sweet spot: warm, dry, sunny and clear, before the haze builds. They're also peak season, so rentals and flights cost more and the best condos lease fast. For value, the rainy months of June to August bring lower prices, lush surroundings and cleaner air, at the cost of daily afternoon storms. The two windows to plan around are April (peak heat plus Songkran) and the January–April haze. If you're house-hunting, arriving in the cool season lets you view buildings comfortably; if you're optimising budget, a rainy-season move can save meaningfully on rent and moving costs.
November to February — the cool, dry season — is the most comfortable time, with lower humidity, clear skies and very little rain. It is the easiest window to house-hunt and settle in, though it is also peak season for prices and rental demand. If you want lower costs and don't mind daily afternoon storms, the rainy months of June to August offer real value.
Bangkok is hot all year. Daytime highs sit around 31–33°C even in the 'cool' season and climb to 35–40°C at the April peak, with high humidity making it feel hotter. Nights are mildest from December to January (lows of 21–23°C). Air-conditioning is standard in condos, malls, offices and transport.
The southwest monsoon runs roughly from May to October, with September the wettest month. Rain usually comes as a heavy afternoon or evening downpour lasting an hour or two rather than all-day drizzle, so it rarely ruins a full day. September and October carry the highest risk of localised street flooding after sustained storms.
Yes, seasonally. From roughly January to April, agricultural crop burning across the region combines with still, dry air to push PM2.5 levels into the unhealthy range on the worst days, creating a visible haze. Air quality is much better during the rainy season, when rain washes the air clean. Many residents track a daily air-quality index, run air purifiers indoors and wear N95 masks on bad days.
Localised flooding is common during heavy monsoon downpours, especially in September and October, when low-lying streets and some districts can hold water for a few hours until drains catch up. Serious city-wide flooding (like 2011) is rare. When choosing an area and a condo, it's worth asking about drainage and whether the immediate streets are flood-prone.
Lightweight, breathable clothing year-round; a compact umbrella or packable rain jacket for the May–October monsoon; a light layer for fiercely air-conditioned malls, offices and transit; strong sunscreen and a hat for the hot season; and an N95 mask for the worst burning-season haze days. Modest clothing that covers shoulders and knees is needed for temple visits.
Primary and official sources are cited above. Government rules, fees and procedures in Thailand change over time and vary by office; always confirm current requirements with the relevant authority before relying on them. BAANLYY never takes paid placement in editorial content.
Match the season to your plans, then match your budget to the right Bangkok area and condo tower.
Hero photo by Follow Fauzia on Pexels.