Melbourne's famously temperamental weather is menacing the AFL grand final, with backyard barbecues, the half-time entertainment and even the traditional player parade under threat.

The temperature is set to plummet to 14 degrees for Saturday's grand final, with icy winds and the possibility of hail.

Heavy rain on Friday would also force Sydney and Hawthorn players to greet 100,000 fans from beneath umbrellas for the grand final parade through the city's CBD.

AFL chief executive Andrew Demetriou said the league had contingency plans for its revamped grand final entertainment should the dismal weather set in.

Melbourne rock band Temper Trap will perform at half time before joining Australian music veteran Paul Kelly for a concert at the MCG post match, in a move away from the traditional pre-match performances.

Mr Demetriou said heavy rain would force the Temper Trap set to be shifted from the playing surface to a platform in the stands, with the post match concert also jeopardised.

But regardless of the weather, Mr Demetriou said the entertainment line-up would make up for the disastrous performance of Meat Loaf before the 2011 grand final.

The veteran rocker struggled to hit his notes in a performance that was widely criticised.

"When these guys (Temper Trap) come on at half time, I think hopefully we'll put Meat Loaf behind us, hopefully it will be buried," Mr Demetriou told reporters at the MCG on Thursday.

"You'll hear a fantastic sound system this year compared to previous years, you're going to see a pre-match like you've never seen before, a half time like you've never seen before and I promise you that post match, weather permitting, there will be a great concert just before we bring out the premiership team."

The weather bureau is predicting a mild 21 degrees for Friday, with the chance of thunderstorms, before conditions turn grim on Saturday.

"There's not going to be a huge number of showers on Saturday but the main point we're stressing is that it's going to be very cold and windy with the chance of hail and thunder," senior forecaster Gary Missen said.

Mr Demetriou said in the unlikely event of a downpour on Friday the AFL could call off the parade.

"If it was too heavy then you couldn't have the players out in the parade, but we're not even thinking about that, we're thinking about the parade proceeding because we want everybody to celebrate the players," he said.

Lorenzo, from Temper Trap, said the group was honoured to be headlining the grand final entertainment line-up.

"We grew up here so we know the importance of grand final day," he said.

He said he had missed Meat Loaf's 2011 pre-match show.

"You're lucky," Mr Demetriou told him.