PETALING JAYA - Malaysia on Saturday (Oct 3) issued a warning of low visibility of less than 5km over the waters off nine states as a result of the haze.

The Meteorological Department said in a statement that Kedah, Penang, Perak, Selangor, Negeri Sembilan, Malacca, Johor, Pahang and Sarawak were affected by the low visibility, the Bernama news agency reported.

Thirteen areas in the country - including Johor, Malacca, Negeri Sembilan, Selangor, Kuala Lumpur and Putrajaya - saw unhealthy air quality as of 11am on Saturday (Oct 3), according to data from the Department of Energy's website.

The poorest air quality was recorded in Nilai, Negeri Sembilan with an Air Pollutant Index (API) reading of 142, while Port Klang in Selangor (133) and Malacca City (127) also saw high API readings.

A reading of 100 to 200 indicates unhealthy air quality, while 201 to 300 is very unhealthy and above 300 hazardous. A reading of 51 to 100 is moderate.

The country's haze is expected to dissipate somewhat with better air quality from Tuesday, The Star reported.

The report, citing the Meteorological Department, said air quality would improve due to tropical storm Mujigae, which is expected to hit China's Hainan island on Monday.

The Natural Resources and Environment Ministry has also said the country's overall weather was improving with fewer areas recording unhealthy API readings.