If you've noticed a burnt smell in the air over the past few evenings and are wondering if it's the haze at work, here's why.The National Environment Agency (NEA) said in a Facebook post on Friday (March 20) evening that hotspots with smoke plumes were observed in Central Sumatra and Johor.Noting the dry and warm conditions over Singapore and the surrounding region from this weekend until the end of next week, along with prevailing winds from the northeast, NEA said that there may be an increase in hotspot activity and a «continued risk of smoke haze».Checks by AsiaOne on the agency's 1-hour PM2.5 reading at 11.30pm indicate that Singapore's air quality remains in the «normal» band.The 24-hour Pollutant Standard Index ranged from 45 to 57, within the «Good» to «Moderate» range, as at 7pm.Warmer conditions expectedDaily maximum temperatures in Singapore may reach a high of 35 to 36 deg C on some days in the coming week, NEA said. Read more