In 1991, the country experienced very hazy weather condition due to the forest fires in Sumatra. After a lapse of three years, during the month of September 1994 the haze recurred and lasted for over a month, only this time more severe compared to 1991. Serious forest fires in Kalimantan and Southern Sumatra were again identified as the main cause of the problem. The dry weather, and stable lower wind conditions coupled with emissions from local pollution sources such as from motor vehicles, industries, and open burning of wastes also aggravated the situation.