As we enter the final straight before the big race, and the weather forecast for the day starts to firm, there is good news and bad news.

The good news is that (as of Thursday afternoon) the rain on Sunday is now expected to be light - just one to five millimetres is being forecast, though it is going to follow a real drenching on Saturday.

READ ALSO:

And the bad news? The bad news is that those who have come from warmer climes to be trackside for the Bathurst 1000 are going to wonder what happened to spring because a top of just 13 degrees is predicted.

To give that some context, that will be a full seven degrees below Bathurst's long-term maximum average for October (20 degrees) and three degrees lower than the 16 degrees that Bathurst has been averaging this month.

It will be 10 degrees lower than the 23 degrees forecast for Sydney's CBD on Saturday and 21 degrees lower than Bathurst's highest October maximum temperature on record (34 degrees).

In short, it's going to be cold.

For the Bathurst veterans, who've grown used to experiencing four seasons in one day on the Mountain, Sunday's forecast will be unsurprising and unremarkable.

For everyone else, be prepared.