So, you're looking at the Bangkok 10 day forecast and thinking it's all smooth sailing because it's the "cool season."
Honestly? That’s a bit of a trap.
While the brochures promise crisp mornings and mild afternoons, the reality on the ground right now—Sunday, January 18, 2026—is a mix of "mostly cloudy" skies and a sticky 90°F. If you’re packing nothing but light sweaters, you’ve got another thing coming.
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The heat isn't the only thing you should be worried about. The air quality is currently a bigger conversation in the city than the temperature itself.
The Immediate Numbers: What’s Happening Now
Right now, Bangkok is sitting at a solid 90°F. The wind is barely a whisper, coming from the south at just 2 mph.
Humidity is hovering around 39%, which sounds low until you realize the dew point is high enough to make your shirt cling to your back the moment you step out of a BTS station.
The forecast for the rest of today, January 18, suggests a 35% chance of rain during the daytime. It’s that classic Bangkok "partly sunny but maybe a sudden downpour" vibe. Tonight, things "cool" down to 75°F with a southeast wind picking up slightly to 5 mph.
Breaking Down the Bangkok 10 day forecast
If you're planning your itinerary for the next week, here is the raw data you need to know, stripped of the travel agency fluff.
Tomorrow, Monday, January 19, looks almost identical to today. Expect a high of 89°F and a low of 76°F. The UV index is a 5, which is moderate but still enough to crisp you if you’re hanging out at a rooftop bar all afternoon.
By mid-week, the rain chances drop off significantly. Tuesday and Wednesday (January 20-21) both hold steady with highs of 89°F. Tuesday has a slight 15% chance of rain, while Wednesday is even drier at 10%.
Interestingly, the humidity starts to dip as we head into the weekend. By Friday, January 23, we’re looking at 39% humidity and a much stronger breeze—10 mph from the east. That might actually feel "cool" compared to the stagnant air we have right now.
The real heat spike hits at the end of this 10-day window. On Wednesday, January 28, the forecast predicts a jump to 94°F. That’s a big leap from the 89-degree average we’ve been seeing.
The Elephant in the Room: PM2.5 and Air Quality
You can’t talk about the Bangkok weather in January without talking about the haze.
Last week, around January 12-13, the city was actually advising people to work from home because the PM2.5 levels were hitting "orange" status—basically, it's not great for your lungs.
Even though the Bangkok 10 day forecast shows mostly sunny or partly cloudy days, a lot of that "cloud" is actually seasonal smog trapped by low wind speeds and temperature inversions. If you have asthma or sensitive lungs, the "sunny" day on Monday, January 26, might be a mask-up day regardless of how blue the sky looks.
Survival Tips for the Next 10 Days
Don't just look at the high temperatures. Look at the lows.
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A 70°F low on Saturday, January 24, is actually quite pleasant for a night walk through Talat Phlu or a late dinner by the river. That’s the "sweet spot" of this entire forecast.
- Hydrate early: Don't wait until you're dizzy at the Grand Palace.
- Check the wind: Higher wind speeds (like the 10 mph east wind on Friday) usually mean better air quality.
- UV Protection: Even on "mostly cloudy" days, the UV index is hitting 6 or 7. That’s high.
Basically, the next ten days are a game of managing the midday heat and watching the air quality reports as closely as the rain chance.
Next Steps for Your Trip
If you're heading out today, keep an eye on the sky for that 35% rain chance this afternoon. For the upcoming week, prioritize your outdoor sightseeing for the mornings between Friday and Sunday when the humidity is lower and the breeze is stronger.