Bangkok heat index hits dangerous level despite good air

Bangkok’s air quality remained in the “good” range on Sunday morning, but authorities warned that extreme heat had become the capital’s main immediate health concern.

According to the Bangkok Air Quality Information Centre, in cooperation with the Environment Department and the Thai Meteorological Department, the average PM2.5 level in Bangkok at 7am on April 19, 2026, stood at 23.9 micrograms per cubic metre and was continuing to decline.

Heat risk overtakes dust as main concern

Despite the improving air quality, officials said the heat index had climbed to the “dangerous” level.

The heat index reflects the temperature the body actually feels, taking into account both air temperature and relative humidity. Authorities said this measure can pose a greater health risk than air temperature alone. For April 19, Bangkok’s maximum heat index was forecast at 42.0-51.9C, placing it in the dangerous category.

Vulnerable groups urged to watch for warning signs

At that level, the public was urged to monitor physical symptoms closely, especially vulnerable groups such as young children, older people, pregnant women, people with underlying medical conditions, and those working outdoors for long periods.

Officials warned that symptoms such as fatigue, dizziness, nausea or fainting should not be ignored, and said anyone experiencing them should seek medical attention immediately.

Public advised to avoid midday outdoor activity

Authorities recommended avoiding outdoor activity between 11am and 3pm, drinking water regularly, and resting in well-ventilated places or cooling areas.

They added that prolonged exposure to extreme heat could lead to heat stress and increase the risk of heat stroke, which is considered a medical emergency.

Although PM2.5 levels in many parts of Bangkok remained at moderate to good levels and did not exceed the standard limit, officials stressed that heat had now become the dominant health risk during this period.

Residents were advised to keep monitoring both air-quality and heat updates closely and to contact emergency medical services immediately if needed.