Bush fires on the outskirts of Sydney are expected to affect the third cricket test between New Zealand and Australia today.
After a relatively clear first day during which air quality never dropped below a "fair" rating, the weather is expected to bring smoke from fires into the city which will negatively affect that rating.
New South Wales' Department of Planning, Industry and Environment has predicted an air quality rating of "poor" for today's play as the city deals with sweltering 45C heat and blustery winds.
The Black Caps have said they are happy to follow advice from Cricket Australia and match officials when it comes to how this could affect play.
"We're comfortable with them (the guidelines)," Black Caps coach Gary Stead said after day one.