Just days before Singapore's annual Formula One race weekend was set to begin, smog caused by wildfires in Indonesia blanketed the region, pushing the city-state's air pollution to the worst level in the world.

According to IQAir data, Singapore's air quality stood in the "very unhealthy" range as of Wednesday afternoon. Neighboring Kuala Lumpur currently ranks second among the world's most polluted cities, having previously held the top spot.

Local media reported that roughly 200 schools, kindergartens, and childcare centers in the Batu Pahat area of Johor state in Malaysia, located about 140 kilometers northwest of Singapore, were ordered to close today due to the hazy conditions.

Singapore's National Environment Agency said in its latest outlook that dry weather is expected to persist across much of southern Southeast Asia in the coming days, keeping the risk of fires and transboundary haze elevated. The agency's data also showed that air quality across all five regions of the city was at unhealthy levels.

A spokesperson for Singapore GP Pte Ltd, the company responsible for organizing the F1 event, said on Tuesday that if the haze leads to reduced visibility, affects public health, or causes operational issues, the company will work closely with relevant agencies to "assess the situation before making any collective decision regarding the race."

A Formula One spokesperson said the current situation is not yet a cause for concern.