The Bureau of Meteorology is predicting showers in the Harbour City on Saturday afternoon, but said the rest of the weekend's finals should be played in fine conditions.
"The Sydney one is the one that's risky, (there) could be some showers, (with a temperature of) about 19 degrees," duty forecast Scott Williams told AFL.com.au on Monday.
"Apart from that, the first weekend looks like pretty good conditions for footy.”
Both MCG matches, featuring Hawthorn and Geelong on Friday night at 7.50pm and North Melbourne and Essendon on Saturday night at 7.15pm, are tipped to be played in fine weather.
"It'll be fine and cool to mild weather, it'll be more like 12 degrees during those games,” Williams said.
"It looks like the Adelaide game will be played in fine weather, about 22 (degrees).
"(But) no rain and not much wind for the games down here (Melbourne) and Adelaide."
However, when it comes to predicting conditions for the Grand Final on Saturday 27 September, Williams said it was too early to tell because conditions were "highly variable."
"It could be anything, it's the very changeable nature of the weather at this time of year," he said.
"In the late '80s we had a Grand Final that was over 30 degrees."
Meanwhile, ANZ Stadium officials have pointed to August's historic rainfall in Sydney as a factor in the state of the ground, following criticism of the surface after Saturday's Swans-Tigers clash.
Players frequently slipped over during the game at a venue which has drawn fire for its surface conditions in previous seasons.
In one instance late in Saturday's game, Sydney defender Ted Richards lost his footing, allowing Richmond's Dustin Martin a clear run to score what turned out to be the match-winning goal.
A retractable roof is scheduled to be fitted as part of a major upgrade of the venue in 2018.
"Western Sydney has experienced its wettest August in history and this obviously affected playing conditions last Saturday," an ANZ Stadium spokesperson told AAP.
"The stadium is about to undergo a major redeployment with plans for a retractable roof.
"It would be nice to have the ability to close the roof in future."
The Swans are contracted to play three games a year at ANZ Stadium until 2016.
Saturday's match was played just two days after an NRL game at the venue.
There are no rugby league games scheduled at the venue this week leading up to the Swans' qualifying final with Fremantle.
