Despite temperatures taking a slight dip from recent mid-20s highs for the rest of this week, Sydney is still on track to record its hottest autumn ever.

All the city needs to do is hit the forecasted highs of 18 and 19 degrees over the next two days to break the record for mean maximum daily temperature at Observatory Hill, which currently stands at 24.8 degrees.

The likelihood of hitting a new temperature record for autumn shouldn't come as a surprise after Sydney's scorching April, which smashed its monthly temperature record. March was also unusually warm.

As for rain, although the few drops set to fall on Tuesday night should be enough to collect the smoke haze blanketing Sydney's skies and wash it to earth, it won't be more than a few millimetres, said weather bureau duty forecaster Stephen Stefanac.

"There's a chance of some showers later in the week along the Sydney coast and central-northern parts of NSW coast. A few more millimetres to be picked up there."

Apart from that, the dry and warmer-than-average trend is continuing.