CHIANG RAI– The Thai Meteorological Department (TMD) has issued a northern Thailand weather alert for Tuesday, April 7, 2026, warning of a severe heatwave and deteriorating air quality.
A powerful heat low-pressure cell currently sits over upper Thailand, pushing temperatures to “very hot” levels across several provinces while trapping a thick layer of haze over the capital.
Weather experts are advising the public to take immediate health precautions. With the mercury expected to hit a blistering 42°C (107.6°F)in parts of the North, the risk of heatstroke and respiratory issues is at an annual high.
Northern Thailand: A Dual Crisis of Heat and Haze
The situation in Northern Thailand has reached a critical point. Residents are facing a “double whammy” of extreme thermal stress and dangerous air pollution.
Record-Breaking Temperatures
The TMD predicts that the North will be the hottest region in the country today. Maximum temperatures are forecasted to range between 36°C and 42°C. This level of heat is considered dangerous for anyone spending extended time outdoors, especially between the hours of 11:00 AM and 4:00 PM.
Chiang Rai and the Air Quality Crisis
In Chiang Rai, the situation is particularly grim. The province is currently shrouded in a dense layer of PM2.5 dust. Local monitoring stations have reported air quality levels in the “red zone,” which signifies levels that are hazardous to all residents, not just vulnerable groups.
- Hotspots and Stagnant Air:The lack of wind and the presence of agricultural burning—both domestic and transboundary—have caused smoke to settle in the valleys of Chiang Rai and neighboring Mae Hong Son.
- Health Warnings:Local health officials in Chiang Rai are urging residents to wear N95 masks if they must go outside and to avoid all outdoor exercise.
- Emergency Measures:Several provinces in the North have activated Public Health Emergency Operations Centres (PHEOC) to manage the surge in respiratory-related hospital visits.
Bangkok and Central Plains: The Haze Returns
While the North swelters, Bangkok and the surrounding metropolitan area are waking up to a skyline blurred by haze.
The TMD reports that weak southerly winds are failing to disperse the accumulation of dust and vehicle emissions. While the temperatures in the capital are slightly lower than in the North—peaking around 35°C to 41°C—the high humidity makes the “feels like” temperature, or heat index, much higher.
Regional Weather Breakdown for Tuesday, April 7
The following is the official regional forecast provided by the Thai Meteorological Department :
- Northern Region:Hot to very hot with haze during the day. Scattered light thunder showers are possible in some areas, but they will bring little relief from the heat.
- Low: 20–27°C | High: 36–42°C.
- Northeastern Region:Hot to very hot conditions. Smoke and haze will persist, particularly in the western and lower parts of the region.
- Low: 21–27°C | High: 37–41°C.
- Central Region (including Bangkok):Hazy and hot during the day. Very hot in some provinces. Residents should expect a “heavy” atmosphere due to the lack of air movement.
- Low: 24–28°C | High: 38–42°C.
- Eastern Region:Hot with haze during the day. Some isolated thundershowers may occur along the coast.
- Low: 24–28°C | High: 34–40°C.
- Southern Region (East Coast):Hot with isolated thundershowers. Generally better air quality than in the north.
- Low: 22–27°C | High: 34–39°C.
- Southern Region (West Coast):Hot with scattered thundershowers and gusty winds in some areas.
- Low: 23–27°C | High: 34–38°C.
Understanding the “Heat Low”
The current weather pattern is driven by what meteorologists call a heat low-pressure cell. This occurs when the sun intensely heats the land surface, causing the air to rise and creating a vacuum that stays stationary.
Because the air is not moving horizontally, all the pollutants—including dust from construction, exhaust from cars, and smoke from fires—stay trapped near the ground. This is why the air quality in places like Chiang Rai and Bangkok feels so “thick” during these heatwaves.
How to Stay Safe During the Heatwave
The Ministry of Public Health has issued the following guidelines for today:
- Hydrate Constantly:Drink water even if you don’t feel thirsty. Avoid caffeine and alcohol, as they dehydrate the body faster.
- Monitor Vulnerable Groups:Check on the elderly, young children, and people with chronic heart or lung conditions.
- Dress Appropriately:Wear light-colored, loose-fitting cotton clothing to help your body cool down.
- Recognize Heatstroke:Symptoms include a very high body temperature, red and dry skin (no sweating), a rapid pulse, and dizziness. If someone shows these signs, seek medical help immediately.
- Mask Up:In Northern Thailand and Bangkok, use an N95 mask to filter out the fine PM2.5 particles that can enter the bloodstream.
The TMD expects these conditions to persist for the remainder of the week. While isolated thundershowers are mentioned in the forecast, they are unlikely to be widespread enough to significantly lower the temperatures or clear the air.
For now, the message to the Thai public is clear: stay indoors where possible, keep cool, and stay informed through official weather apps like Air4Thai for real-time pollution updates.
