The weather and climate in Bangkok come in two varieties: hot and dry or hot and wet. The seasons are mostly predictable aside from years when Mother Nature decides to throw a climate curveball, which happens.
The best months to visit Bangkok are typically December and January (holiday escape, anyone?) when rainfall and humidity are at their lowest. Average temperatures are relatively cool until they climb in March and peak in April. By that time, everyone is ready for the rainy season to begin in May.
One thing is certain concerning the weather in Bangkok: unless you’re being slowly frozen by the superpowered air conditioning, you’ll never be cold. High humidity and urban pollution make for three-shower-a-day temperatures in Thailand’s City of Angels.
Fast Climate Facts
- Hottest Month: April (89 F / 31.7 C)
- Coolest Month: January ( 82 F / 27.8 C)
- Wettest Month: September (12.26 inches / 311 mm of rain)
- Sunniest Months: December to March
- Months with the Lowest Humidity: December and January
The Monsoon Season in Bangkok
Monsoon season runs roughly from May until November, plus or minus some weeks on either end.
Fall is a very rainy time to be in Bangkok. As runoff from Ayutthaya and upstream destinations flows into the Chao Phraya River, flooding has become an annual problem.
Many improvements have been made since the catastrophic flooding in October 2011, however, parts of the city still wind up inundated. When this happens, street closures affect transportation. Traffic, already a frustrating challenge, gets rerouted and becomes worse. Plan extra time for delays if you’re heading to either of the airports.
Spring in Bangkok
Spring in Bangkok can be scorchingly hot. Temperatures and humidity hit their highs in March and April until the monsoon season brings rain in May. For a while, heavy showers and sunshine compete for bright afternoons. Torrential squalls may only last an hour before evaporating into high humidity.
Songkran, Thailand’s traditional New Year festival from April 13-15, is the biggest event in the country. Although Chiang Mai is the epicenter, Bangkok will be busy. Fortunately, part of the celebration includes throwing cold water at each other — certainly welcome in April’s heat.
The average humidity for spring months is usually between 70-73 percent.
What to Pack: With excessive sweating pretty well guaranteed, you’ll need more tops and shirts than usual. Plan to do laundry or consider purchasing additional tops from one of Bangkok’s sprawling malls.
- March: 87 F / 30.6 C (1.94 inches / 49 mm of rainfall)
- April: 89 F / 31.7 C (3.40 inches / 86 mm of rainfall)
- May: 88 F / 31.1 C (7.97 inches / 202 mm of rainfall)
Summer in Bangkok
Summer brings the start of the rainy season in Bangkok. Although showers are frequent, they don’t last forever. The rain isn’t yet as intense as the torrential downpours in fall. Afternoon showers help clean dust and pollution particles from the air, making breathing a little easier.
If you don’t mind some rain here and there, the summer months can be a less busy time to visit. Discounts are easier to find during the low season. Many travelers opt for Bali where the dry season runs through summer, so you’ll have a little more room at big attractions in Bangkok.
The average humidity for summer months in Bangkok is usually around 76 percent.
What to Pack: Along with the usual items to bring to Thailand, have a good plan for waterproofing your passport and other valuables that won’t survive a soaking.
- June: 87 F / 30.6 C (7.30 inches / 185 mm of rainfall)
- July: 86 F / 30 C (8.69 inches / 221 mm of rainfall)
- August: 86 F / 30 C (7.30 inches / 185 mm of rainfall)
Fall in Bangkok
With September and October being the rainiest months, fall is a wet time to be in Bangkok. Outside activities will be affected. Flooding may occasionally cause traffic to become an even bigger problem. Fortunately, there are many nice nearby escapes from the big city.
Fall can still be enjoyed in Bangkok, but plan to spend a fair amount of time indoors. September and October feel like the calm before the busy-season storm that hits in late November.
The average humidity for fall in Bangkok is between 70-79 percent.
What to Pack: Consider bringing rain gear, but no need to carry an umbrella around the world. They’ll be for sale everywhere you look!
- September: 85 F / 29.4 C (12.26 inches / 311 mm of rainfall)
- October: 85 F / 29.4 C (9.85 inches / 250 mm of rainfall)
- November: 85 F / 29.4 C (1.92 inches / 49 mm of rainfall)
Winter in Bangkok
Winter is the best time to be in Bangkok. Not only can you escape the cold at home, winter is the driest and most comfortable season to travel in Thailand. The heat isn’t nearly as oppressive, and days are almost always sunny.
As you could guess, winter is also the busiest time to travel in Bangkok and Thailand. Everyone wants to take advantage of the ideal weather. The Christmas and New Year holiday season are especially busy in the islands as travelers swap white snow for white sand.
Note: November is the start of dry season in Bangkok but not necessarily the islands. If diving is your plan, November is often a very rainy month in the Samui Archipelago, which includes the diving hotspot of Koh Tao. Runoff may make visibility less than ideal. Instead, consider doing your diving and sunbathing along the Andaman coast (Phuket, Koh Phi Phi, or Koh Lanta).
The average humidity for winter months in Bangkok is between 64-70 percent.
What to Pack: Bring good sunscreen from home; you may find fewer choices and higher prices locally. Sunglasses are for sale everywhere, although UV protection of the cheapies is questionable. Flip-flops (or easily removable sandals) are the default footwear choice. You’ll need to take them off before entering temples, homes, and some businesses.
Average Temperatures and Rainfall by Month
- December: 83 F / 28.3 C (0.55 inches / 14 mm of rainfall)
- January: 82 F / 27.8 C (1.06 inches / 27 mm of rainfall)
- February: 85 F / 29.4 C (1.22 inches / 31 mm of rainfall)
Average Monthly Temperature, Rainfall, and Daylight Hours
Mean Temperature | Rainfall | Hours of Sunlight
- January: 82 F (27.8 C) | 1.06 inches (27 mm) | 272.8 hours
- February: 85 F (29.4 C) | 1.22 inches (31 mm) | 251.4 hours
- March: 87 F (30.6 C) | 1.94 inches (49 mm) | 269.7 hours
- April: 89 F (31.7 C) | 3.40 inches (86 mm) | 258 hours
- May: 88 F (31.1 C) | 7.97 inches (202 mm) | 217 hours
- June: 87 F (30.6 C) | 7.30 inches (185 mm) | 177 hours
- July: 86 F (30 C) | 8.69 inches (221 mm) | 170.5 hours
- August: 86 F (30 C) | 7.30 inches (185 mm) | 161.2 hours
- September: 85 F (29.4 C) | 12.26 inches (311 mm) | 156 hours
- October: 85 F (29.4 C) | 9.85 inches (250 mm) | 198.4 hours
- November: 85 F (29.4 C) | 1.92 inches (49 mm) | 234 hours
- December: 83 F (28.3 C) | 0.55 inches (14 mm) | 263.5 hours