It is one of the largest donations received for the event, which has a budget of $3.8 million.
WGNZ chief executive Arthur Klap said he was "extremely grateful" for the support which was "critical" for the running of the event.
More than 800 of the world's top snow and ice sports athletes from 41 countries are expected to attend.
The games will be held over 17 days across the region, with events in Dunedin, Wanaka, Queenstown, Naseby and Methven.
"Currently, the budget for the coming games, excluding the off-venue, festival-type activities, is $3.8 million.
"That's our total budget and we [have secured] around about 80% of that funding at the moment.
"Every extra bit of funding we get helps us to deliver the best games - that $100,000 helps enormously."
The inaugural WGNZ was held in 2009 with a budget of $2.2 million.
At the end of the event there was a $19,000 surplus.
"Every dollar makes a big difference," Mr Klap said.
Funding applications were still pending from several organisations, including the Community Trust of Southland, with several sponsors also pending.
"We do think the Christchurch earthquake will have an impact - there's $200,000 or so potential income that we would have got [which won't be coming now].
"One company that was a really strong sponsor is now in survival mode, so they have had to pull out.
"Otago will benefit from a large tourist influx, our local athletes will benefit from increased competition, and the exposure of Otago via the media to overseas audiences will be greatly enhanced.
"The games are important for Otago, Canterbury and Southland anyway, but now they're even more important because they're delivering jobs and the economic impact from the spend that we do, plus the international dollars [is important], also the extra positive promotion that we're doing internationally for New Zealand and the South Island."
A "greatly increased" programme was on the cards this year, with plenty of involvement planned for Central Otago and Dunedin people.
For example, the programme at the Dunedin Ice Stadium had been extended from five to 11 days, with a larger ice hockey tournament, figure skating including a gala performance and speed skating.
All the snowboard and free ski events would be held in the Wanaka region and the alpine ski racing events would be held in Queenstown.
The festival programme was expected to be announced next month, which would include activities in the Octagon in Dunedin and downtown Queenstown.
Otago Community Trust chief executive Keith Ellwood said given the success of the inaugural WGNZ and the "potential contribution" the games would make to the region, the trust was "happy to lend our support to the event".
