If you stepped outside early today and felt that sharp, dry chill, you’re not imagining it. A moderate cold air mass and high pressure are sitting over upper Thailand and stretching into the upper South. It’s the kind of setup that makes mornings feel brisk, then flips to warmer sunshine by late morning.
The coldest start is in the North and Northeast, where some places can dip near 13°C around sunrise. The biggest day-to-day risks aren’t dramatic storms up north, they’re practical ones: morning fog that cuts visibility for drivers, and a few isolated thunderstorms down south that can make roads slick in minutes.
For local, day-to-day updates, many readers follow Chiangraitimes alongside official sources, especially when travel plans depend on early-morning conditions.
Thailand weather today: key numbers
Here’s the quick, at-a-glance view for planning school runs, commutes, hikes, and boat trips:
- Coldest morning low: near 13°C in parts of the North and Northeast (especially sheltered inland areas).
- Upper Thailand trend: slightly warmer than the previous day in many places (a common pattern when the cold air mass starts to weaken).
- Fog risk: light morning fog in many areas, with thicker patches in some spots, especially near fields, canals, and rivers.
- Bangkok morning feel: cooler early, then warming quickly by late morning.
- Rain risk (South): lower overall, but isolated thunderstorms can still pop up.
- Upper Gulf of Thailand waves: 1 to 2 meters.
- Lower Gulf waves: around 2 meters.
- In thunderstorm areas at sea, waves can rise above 2 meters quickly.
- Best timing for outdoor plans: late morning through mid-afternoon is often the most comfortable in this setup (cool start, warmer later).
What is driving the cooler air right now?
Think of a cold air mass as a big, heavy lid of cooler, drier air sliding down from the north. When it settles over upper Thailand, it brings cooler mornings and calmer weather overall.
That calm air matters. With less wind overnight, moisture near the ground can’t mix upward, so it collects in low spots. By sunrise, the air near the ground cools enough for that moisture to turn into fog, especially where there’s water nearby or damp ground from earlier humidity.
Region by region forecast: what to expect where you live or travel
This is the section to read twice if you’re on the road early, riding a motorbike, or catching a bus before sunrise. Most regions will feel cool first thing, then noticeably warmer after breakfast.
North and Northeast: coldest mornings, warmer afternoons
In the North and Northeast, mornings stay cool to cold. Some areas can start near 13°C, with colder air on higher ground. If you’re heading to viewpoints or mountain roads, the early hours can feel much colder than the thermometer suggests, because wind on ridgelines bites through thin clothing.
Fog can form in valleys and near rivers. That’s when a familiar drive becomes tricky, because visibility can drop fast on curves and near shaded stretches of road.
By late morning, the sun usually takes over. Afternoons turn comfortable, even warm, especially in open areas. The best plan is simple: dress for two different days. A light jacket or hoodie for sunrise, then something breathable underneath so you’re not sweating by noon.
If you want a wider view of Thailand weather hazards across the year, including periods with very different risks, the Chiang Rai Times weather desk keeps a running watchlist in its heavy rain warnings and severe weather updates.
Central region plus Bangkok and the East: cooler air with morning fog
Central Thailand, Bangkok, and the East tend to feel cool early in this pattern, but the bigger issue is fog. It often sits low over roads and canals, and it can be patchy, clear for 200 meters, then suddenly white again.
For commuters, that’s a visibility problem more than a comfort problem. If you’re on a motorbike, the combination of fog and dew can also make bridges, painted lane markings, and shaded corners a bit slippery at speed.
The good news is that the cool air doesn’t usually last all day here. Once the sun gets up, the fog burns off and it warms quickly. A thin outer layer you can remove easily is the smartest choice.
If you’re tracking the official daily write-up, the Thailand Meteorological Department daily forecast is the quickest way to confirm morning fog mentions and regional notes.
Upper South and Lower South: fewer showers, but storms can still pop up
The upper South (closer to Central Thailand) also feels the influence of the high-pressure system, so mornings can be cooler than usual. Fog can show up in some inland areas, especially near farmland and low-lying roads.
In the lower South, rainfall is lower overall today, but don’t treat it as “no storm” weather. The northeast monsoon pattern can still trigger isolated thunderstorms, and those storms can be intense for a short time. If you’re planning beach travel, island transfers, or long drives between provinces, keep your timing flexible. A single storm cell can soak one stretch of highway while the next district stays dry.
For a plain-language news summary of the same pattern (cool mornings up top, fog risk, and isolated storms south), see this Nation Thailand cold air update.
Travel and safety advice (Thailand)
Most days like this are easy to manage. The problems happen when people treat fog like light rain, or dress for midday heat and forget about the cold start at 6 am.
Fog safety checklist for drivers and riders
- Slow down and drive to what you can see ahead.
- Use lights (low beam is usually best in fog).
- Increase following distance because braking takes longer on damp roads.
- Avoid speeding on motorbikes, especially on bridges and flyovers.
- Keep your visor and glasses clean and clear before you start.
- Avoid sudden lane changes, other drivers may not see you.
- If visibility gets too poor, pull over safely in a well-lit spot, then wait it out.
Cold weather health checklist for families and outdoor workers
- Dress in layers so you can adjust as the day warms.
- Have warm drinks in the morning, especially for kids.
- Watch kids and elderly for shivering or unusual tiredness.
- If you have asthma or allergies, keep meds handy, cool air can trigger symptoms.
- Stay dry, damp clothes cool your body quickly.
- Warm up before exercise if you run or cycle early.
- Keep bedrooms ventilated safely, avoid sealing rooms completely when using fans or blankets.
Sea conditions: Gulf of Thailand and Andaman Sea
Boat users should treat today as “mostly workable, but don’t push your luck.” Winds are moderate, and seas are generally moderate, but thunderstorms can change wave height fast.
Wave guidance to plan around:
- Upper Gulf of Thailand: 1 to 2 meters
- Lower Gulf: around 2 meters
- Thunderstorm areas: waves can exceed 2 meters
That last point matters for speedboats, longtail boats, and smaller ferries. A normal-looking morning can turn rough near storm clouds. Mariners should proceed with caution and avoid thunderstorm areas in both the Gulf of Thailand and the Andaman Sea.
For official marine and regional wording, the TMD’s broader Thailand page is a helpful cross-check: Thailand regional forecast from TMD.
Quick decision guide for travelers taking ferries or longtail boats
Before you pay for a crossing, do three quick checks. First, look for operator updates at the pier, don’t rely on yesterday’s conditions. Second, if thunderstorms are nearby, avoid small boats and wait for a calmer window. Third, wear a life jacket even on short rides, especially on longtails where spray and chop can throw balance off.
If you can choose timing, earlier crossings are often calmer in this type of setup. Keep your plan flexible so you’re not forced onto the water when storm clouds build.
Why fog happens in cool-season Thailand, in plain language
A cold air mass is simply a big pool of cooler air. When it moves in over Thailand, nights cool down faster, especially under clear skies. High pressure often brings calmer weather, which sounds nice, but it also means the air near the ground doesn’t mix much.
Here’s the simple chain reaction: cooler night, moist ground, calm air. Near sunrise, the air closest to the ground cools to the point where it can’t hold the same amount of moisture. That moisture turns into tiny water droplets floating in the air, and that’s fog.
Fog loves low places. It forms near rivers, lakes, rice fields, canals, and quiet stretches of highway. Once sunlight warms the ground, the air warms too, and the fog usually fades by mid-morning.
FAQ: Thailand cold weather forecast and safety questions
Why is Thailand colder right now?
A moderate cold air mass and high-pressure system are covering upper Thailand and reaching into the upper South. That brings cooler mornings and calmer winds, which can also lead to fog.
Where is the coldest area in Thailand today?
The North and Northeast are the coldest at sunrise. Some spots can dip near 13°C in the morning, with colder conditions on higher ground.
Is Bangkok cold this week?
Bangkok is cooler than usual in the morning, and fog can form in some areas. It typically warms up later in the day, so expect a cool start and a warmer afternoon.
Why is there morning fog in many areas?
Fog forms when cool night air sits close to the ground and traps moisture. Under high pressure, winds are often lighter, so the moisture lingers until the sun warms things up.
Is it safe to take a boat today in the Gulf of Thailand or the Andaman Sea?
Conditions are generally moderate, but waves can reach 2 meters or more in thunderstorm areas. Follow local warnings, listen to pier staff and operators, and avoid traveling near storm clouds.
Sources and update note: where this forecast comes from and what can change fast
This update follows the Thailand Meteorological Department (TMD), which is the main authority for national forecasts and marine guidance. Start with the official TMD 7-day outlook if you’re planning trips beyond today.
Fog, isolated thunderstorms, and sea conditions can shift quickly at the local level. Before early drives, mountain trips, or boat rides, check the latest updates and local alerts, especially if you see thick fog or storm clouds forming.
Conclusion
Thailand’s weather today is a classic cool-season mix: the North and Northeast get the coldest mornings, with some spots near 13°C, while many other areas face a practical fog risk around sunrise. Central Thailand, Bangkok, the East, and parts of the South can start the day with reduced visibility, then warm up later. At sea, waves are moderate, but can jump higher in storms, so avoid thunderstorm areas in the Gulf and Andaman.
