Residents in the east woke up to the smell of smoke in the air on Tuesday morning, with many wondering if the haze was back after a two-month hiatus.

The three-hour Pollutant Standards Index (PSI) reading stood at 56 as of 2pm. A PSI reading below 50 is classified as 'good' and anything higher than 100 is considered 'unhealthy'.

The haze, caused by forest fires in Sumatra to clear land, last peaked on June 21 when the PSI reading hit 401.

Latest figures from the National Environment Agency website, however, showed that the number of hotspots detected in Sumatra decreased to 82 from 199 on Monday. But on The Straits Times Facebook Page, readers from around the island posted comments that their area looked and smelled hazier.

"City Hall hazy. Came out of Raffles City and I can smell the smoke," said Jasmine Kee. Another reader, 'Boy Mendak' said he thought he smelled some burning around Tampines at about 10.30pm last night.