Singapore has been enveloped by thick haze on Tuesday as smoke from ongoing forest fires in neighboring Indonesia pushes the city-state's air pollution levels into the health-threatening zone. The deteriorating conditions, fueled by drought brought on by the El Nino weather pattern, have caused air quality across all five regions of the island to reach "unhealthy" levels for the first time since September 2019.

According to data from IQAir, Singapore is now ranked among the 10 most polluted cities globally, with Kuala Lumpur and Jakarta also placing high on the list. Indonesia routinely grapples with forest fires during its annual dry season, but this year the number of fire hotspots is significantly higher than usual. Data from the forestry ministry's fire monitoring platform SiPongi reveals that August recorded over 9,000 hotspots, marking the highest monthly total since 2015, while September has already logged more than 7,000 hotspots.

As the El Nino phenomenon continues to strengthen, large parts of Southeast Asia are experiencing increasingly dry conditions. The ASEAN Specialised Meteorological Center has indicated that a marked improvement in weather conditions is unlikely in the near term, with southern Southeast Asia expected to maintain dry weather in the coming period. The agency's latest forecast warns that fire hotspots and haze conditions in the region are expected to deteriorate further, with the risk of transboundary haze remaining a persistent concern.

Government data shows that as of Tuesday, air quality in parts of Kalimantan and Sumatra, where fires are most concentrated, has reached "hazardous" or "very unhealthy" levels. Malaysia is also feeling the effects: severe haze at the end of August forced the government to move its National Day speech indoors, and earlier this month, parts of Sarawak state declared a state of emergency due to the worsening conditions.

Singapore's National Environment Agency stated on Monday that shifting wind patterns are carrying smoke plumes from fires in Kalimantan toward Singapore, while haze from Sumatra is simultaneously affecting local air quality. The agency expects hazy conditions to persist over the next 24 hours.

The dry weather is beginning to impact Indonesia's resource and agricultural sectors. A local nickel producer announced on Tuesday that it will suspend expansion plans at one of its processing plants due to water shortages, while Indonesia's largest nickel industrial park warned earlier this month that it may be forced to reduce output for the same reason. Additionally, palm oil production is expected to be affected as ongoing drought hampers fertilization activities on plantations.