Thailand enters the hot season on Sunday, Feb. 22, 2026, according to the Thai Meteorological Department (TMD), marking the shift into the country’s summer pattern.
Forecasters also warn that early summer storms are possible Feb. 23 to 25 in upper Thailand. After that, the hottest stretch usually builds from mid-March through April. Some northern provinces could top 42°C (108°F), and the heat index (the “feels like” temperature) can climb much higher when humidity stays elevated.
Key takeaways
- Timeline: Thailand hot season 2026 runs from Feb. 22 to mid-May (typical pattern cited by TMD).
- Worst heat: The North faces the highest extreme heat risk, while Bangkok heat index risk can spike because humidity stays high.
- Safety: Watch for Feb. 23 to 25 storms in upper Thailand, then plan for heat safety through April (shade, water, and flexible outdoor timing).
When the hot season starts, how forecasters decide, and how long it should last
Thailand’s hot season start date is tied to a simple idea: upper Thailand turns consistently hot, and the wind pattern shifts. For 2026, TMD says the season begins Sunday, Feb. 22, and should run through mid-May.
In plain terms, official forecasters look for a few signals:
- Widespread heat in upper Thailand, with many areas reaching 35°C (95°F) or higher for several days.
- Wind shifts toward southerly and southeasterly flow, which brings warmer air.
- Cold air outbreaks fade, meaning less influence from winter air pushing down from China.
For day-to-day changes, TMD posts regular updates and region-by-region forecasts. The easiest starting point is the agency’s Thailand daily weather forecast page.
Here’s a mini timeline based on TMD’s current outlook:
- Feb. 22: Hot season begins
- Feb. 23 to 25: Early storm window in upper Thailand
- Mid-March to April: Highest heat risk
- Mid-May: Typical end of the hot season
Forecasts can change quickly, so checking official updates daily matters, especially during the first week of the seasonal switch.
How hot will it get in 2026, and why the heat index can feel worse than the thermometer
Air temperature is what a thermometer measures in the shade. The heat index is what the body feels when humidity makes it harder to cool down through sweat. In other words, two days with the same temperature can feel very different if one day is humid and still.
TMD has warned in past extreme conditions that Thailand’s heat index can reach around 54°C (129°F). That’s not the air temperature. It’s the “feels like” level under intense heat stress, often most likely in April and May when humidity and heat combine.
A simple example helps. If the air temperature sits in the high 30s°C (around 100°F) and humidity stays high, the body can feel as if it’s much hotter, even in the shade. Add direct sun, and the stress rises again.
A few things make the heat index worse:
- High humidity that slows sweat evaporation
- Direct sun on skin and clothing
- Low wind, which reduces cooling
- Asphalt and concrete, which store heat and radiate it back
One practical rule holds up in Thailand’s hot season forecast from February to May: don’t trust “it doesn’t look that hot.” Trust what the body signals, then act fast with shade, water, and rest.
For longer-range signals, TMD also publishes modeling and outlook tools through its seasonal forecast portal, which helps explain why some weeks trend hotter than others.
What we know, and what we do not know yet about peak temperatures
What we know (from TMD reporting and summaries)
- Thailand hot season 2026 starts Feb. 22 and usually ends mid-May.
- Thailand summer storms February 2026 may develop Feb. 23 to 25 in upper Thailand.
- Peak heat risk is expected mid-March to April.
- Some northern provinces, including Lampang, Mae Hong Son, and Tak, may exceed 42°C on certain days.
- Rainfall is expected to be near average as La Niña fades toward neutral conditions.
What we do not know yet
- The exact hottest day for each province.
- District-level storm timing and intensity, including hail risk.
- How long any extreme heat spell will last once it arrives.
We update this article as official forecasts change.
Where heat and storm risk may hit hardest, plus a simple regional planning guide
The hot season doesn’t feel the same everywhere. Geography, humidity, and urban heat all shape risk. Here’s a practical planning view, without guessing city-by-city highs.
- North: Highest risk for extreme heat, with TMD highlighting provinces such as Mae Hong Son, Lampang, and Tak as places that may top 42°C on some days. Outdoor workers face the sharpest risk in mid-afternoon. Dry conditions can also raise wildfire concerns in some periods. For context on how intense northern heat can get, see this Chiang Rai Times explainer on northern Thailand’s record hot season heat.
- Central and Bangkok: Humidity raises the Bangkok heat index, especially for people stuck in traffic or walking between transit stations and tourist sites. The sun reflecting off pavement can make short walks feel longer than expected.
- Northeast and East: Hot daytime conditions are common, with storms possible during the early transition. Local warnings matter because storm impacts can vary sharply over short distances.
- South: Hot and humid weather is typical, but the rain pattern differs by coast and time of year. TMD summaries often show less rain early in the season, then more frequent rain as May approaches.
A quick plan helps many itineraries:
- Early morning: temples, markets, long walks
- Midday: indoor breaks (museums, malls, shaded cafés)
- Late afternoon: outdoor time resumes, with water on hand
Travelers who want cooler breaks in the North sometimes build in higher-elevation stops. This guide to escaping Thailand’s hot season in mountain towns can help compare options by vibe and transport.
Summer storms early in the season, what they are, and a quick safety checklist
Early-season storms can feel sudden because they often form during a weather tug-of-war. Cooler air can still push in from the north while hotter air builds near the surface. When those air masses collide, the atmosphere can flip from quiet to stormy fast.
For 2026, TMD has flagged Feb. 23 to 25 (Mon to Wed) as a risk window for upper Thailand, with thunderstorms, strong winds, and possible hail. These storms can cool temperatures briefly, then the heat returns as skies clear.
A calm checklist reduces risk:
- Move indoors at the first thunder
- Avoid trees, metal poles, and open water
- Secure loose outdoor items, including signs and patio furniture
- For drivers, slow down in heavy rain and watch for debris
For a separate report that also references extreme heat potential this summer, The Nation has covered TMD-linked expectations, including the risk of 42°C-plus days, in Thailand’s 2026 summer forecast report.
Heat health risks, how to spot heat exhaustion early, and what to do fast
Heat illness can start quietly, then snowball. The riskiest hours are often late morning through early evening, when sun and stored ground heat stack up.
This table is a quick reference for common warning signs:
| Warning sign | What it can mean | What to do now |
|---|---|---|
| Heavy sweating | Body is struggling to cool | Move to shade, sip water, rest |
| Dizziness or lightheadedness | Heat strain or low fluids | Sit down, cool the skin, sip fluids |
| Headache | Heat stress and dehydration | Shade, water, cool cloth on neck |
| Nausea | Heat exhaustion may be starting | Stop activity, cool down, sip fluids |
| Muscle cramps | Salt and fluid loss | Rest, drink fluids, consider electrolytes |
| Confusion | Serious heat illness risk | Get help fast, cool the body, call emergency services |
| Fainting | Blood pressure drop from heat | Lay flat in shade, elevate legs, seek help |
| Hot, dry skin | Possible heatstroke | Call for urgent medical help, cool immediately |
Some people face higher risk:
- Kids and older adults
- Pregnant people
- Outdoor workers and delivery riders
- People with heart conditions
- People on certain medications
- Anyone drinking alcohol in the sun
If symptoms start, act quickly: shade first, then cool water, loosen clothing, and use a cool shower or wet cloths on the skin. If confusion appears or symptoms are severe, seek medical care right away.
Practical tips for travelers and tour operators during Thailand hot season 2026
For US, UK, and Canada travelers, the biggest mistake is packing a full-day walking plan like it’s winter. Hot season days often work better in two outdoor blocks, morning and late afternoon.
- Sightseeing: Plan temples and walking tours early, then schedule indoor breaks midday. For Bangkok trip timing and transit tips, this Chiang Rai Times guide on Bangkok hot season temperatures and tips offers practical context.
- What to wear: Light fabric, a hat, sunscreen, and comfortable shoes reduce fatigue.
- Hydration: Mix water with electrolytes, especially after long walks. Reminders help because thirst can lag behind fluid loss.
- Hotels: Confirm air-conditioning reliability and ask about backup power. Pool shade also matters more than most listings admit.
- Transportation: Carry water in taxis. In Bangkok, using BTS and MRT can reduce time in street heat.
- Events: Songkran lands during the hottest period. Water play helps, but heat illness still happens in crowds, so breaks matter.
Storms can disrupt ferries, tours, and outdoor events, so building buffer time into schedules can prevent rushed travel in bad weather.
Photo by Siamways Individualreisen
What to watch next in the next 7 to 14 days
The first two weeks of the season often bring the fastest shifts, because storms and wind direction changes can reset conditions in a single day.
Key items to monitor:
- Storm alerts for Feb. 23 to 25 in upper Thailand
- Any expansion of extreme heat areas in the North
- Heat index Thailand warnings, especially in Bangkok afternoons
- Updates on when conditions start trending toward the rainy season in May
Official updates and regional maps are available through the Thai Meteorological Department website. TMD’s hotline 1182 is also a practical option when severe conditions affect travel or work plans.
Sources we used (Forecasts can change)
- Thai Meteorological Department (TMD) update reported Feb. 19, 2026, plus TMD public forecast pages
- Heat index concept explained using standard meteorological definitions used by public weather agencies
We update this article as official forecasts change.
Conclusion
Thailand hot season 2026 begins Feb. 22, with storms possible early next week, and peak heat risk mid-March to April. The heat index can run far higher than the thermometer, especially in humid areas like Bangkok. Plan outdoor time early or late, take breaks, and follow TMD updates, including the 1182 hotline when conditions turn severe.
