Preparations for the club's hosting of the match between Otago and Thames Valley in Wanaka have been carried out in warm, dry winter conditions.
But club captain Nathan Simon said yesterday the weather forecast was for a wet weekend, beginning this evening.
"We've had it so good - there's been no snow and now it's all coming on game day."
No games have been played on the ground for the past month, so it is in good condition.
It was Mr Simon who arranged for the match to be played at the "most picturesque" rugby ground in New Zealand.
"Otago were making noises about bringing the Ranfurly Shield game to Central, so I took the bull by the horns and put a good proposal through.
"And fair play to Otago for bringing it here because there are turn-key operations such as Alexandra and Queenstown."
While the ground does not have a stand or embankment, a long line of marquees is in place for spectators, and a couple of trucks will provide a little bit of elevation for some.
The club has just completed a major refurbishment of its clubrooms.
Concrete paving went down on Tuesday, and gravel was still being spread around yesterday.
The match is Otago's first defence since it took the shield off Waikato at the end of last season, and 4000 tickets sold out more than a week ago.
Mr Simon said Thames Valley was "here to play".
"They won the Heartland competition last year. They're fizzed up. They don't get many cracks at a shield game."
• The match starts at 2.05pm and is live on Sky.
