A tourist takes a 'selfie' on a bridge overlooking the Singapore skyline choked with smog on September 29, 2015.

Third-quarter gross domestic product (GDP) on tap this week may unveil a foggy economic outlook for Singapore, mirroring the hazy skies that have shrouded the Southeast Asian island-state for the past month due to seasonal pollution from the burning of Indonesia's forests and land.

Advance estimates for the July-September quarter, scheduled for release at 8am local time on Wednesday, are expected to show the economy growing 1.3 percent on-year, according to a Reuters poll.