Singaporeans have been experiencing some hazy air conditions over the past few weeks.

You might have noticed that the burning smell seems to be stronger at night.

Why though?

Poorer air quality at night, explained

While we cannot be certain if burning occurs at night in Johor, air quality in Singapore is definitely poorer at night than during the day.

This is because cooler air temperature traps the pollutants nearer to the ground, resulting in a higher concentration of pollutants at night.

During the day, the sun heats up the ground and warms the air, which creates vertical mixing as the hotter air rises while the cooler air sinks.

This mixing layer grows and disperses the pollutants upwards.

However, the air at night is generally cooler and still, which results in a less vigorous and shallower vertical mixing layer.

Hence, pollutants will remain closer to the ground.

Which explains why the burning smell is more apparent at night.

Dry and itchy skin

The rise in the concentration of pollutants such as carbon monoxide, nitrogen dioxide, and sulfur dioxide can also lead to skin irritation, particularly for those with sensitive skin or eczema.

These chemicals can cause skin inflammation and damage the protective layer of the skin, resulting in faster evaporation of moisture from the skin.

Which is why you might feel itchier whenever the air quality drops.

Top photo collage from ASMC and Zheng Zhangxin