The MetService is currently predicting a damp start, with temperatures of just 17 C, showers, and south-easterlies for the highly anticipated first match between co-hosts New Zealand and Sri Lanka at the redeveloped Hagley Oval.
Duty forecaster David Miller said the forecast rain should clear later on Saturday afternoon.
He stressed that it's still early in the week and the outlook could improve.
"We will be keeping a close eye on that Christchurch forecast. I'm a big cricket fan and I'm hoping it changes as well," said Mr Miller.
The Black Caps' penultimate warm-up match against Zimbabwe at Bert Sutcliffe Oval in Lincoln was washed out after 30.1 overs of New Zealand's innings today, but not before opener Martin Guptill struck a century off just 86 balls.
There is no back up or reserve day for the tournament's pool matches.
If a match is abandoned, teams will be awarded one point each - the same points as awarded for a tie.
Reserve days are in place for quarter-finals, semi-finals and the final at the Melbourne Cricket Ground on March 29.
To constitute a match, it must be a minimum of 20 overs per side. The complicated Duckworth-Lewis mathematical formula will calculate the target score for the team batting second if rain interrupts and then shortens the game.
An ICC Cricket World Cup 2015 spokesman confirmed that ticket holders would get full refunds for washed out matches.
Ticket holders would be eligible for a refund of 100 per cent of the value of the ticket if less than 25 overs were completed and no result was recorded for the match.
There will be a 50 per cent refund if 25 or more overs but less than 50 overs were completed and no result was recorded, the spokesperson said.
The outlook for Thursday's opening ceremony, however, looks perfect.
Sunny skies with temperatures in the mid to high 20s look set for the free event at North Hagley Park from 6.30pm to 10pm.
Organisers yesterday announced that Shapeshifter would be joining Sol3 Mio, Hayley Westenra and Ginny Blackmore on the main stage.
A giant game of backyard cricket will kick off the show, which ends with one of the biggest fireworks displays ever to be held in Christchurch.
Today, Christchurch City Council warned of heavy traffic around the event, and for both commuters and fans going to the opening ceremony, to plan their travel well ahead of time.
"We're asking people to do something different that day," Christchurch Transport Operations Centre Manager Ryan Cooney said.
He urges people to walk to the event if they work or live in the city, or go by bike or bus.
Those not going to the event are advised to use alternate routes.
- Kurt Bayer of NZME. News Service
