But changeable, wet weather was expected to return again on late Friday or Saturday.
While the Australia-USA match in Wellington on Friday is forecast to have clear skies and a light breeze, showers are likely to affect the All Blacks' most important game of the pool round.
Mr McDavitt said: "There is a question mark on the weekend weather, with a few showers around Eden Park on Saturday."
MetService predicted a temperature of 13C for the Auckland match, with almost no wind.
The outlook
Today
* Italy v Russia, Nelson, 7.30pm. 12C, fine with light winds.
Tomorrow:
* Tonga v Japan, Whangarei, 7.30pm. 13C, fine with breezes.
Thursday
* South Africa v Namibia, Albany, 8pm. 13C, cloudy spells and light winds.
Friday
* Australia v USA, Wellington, 8.30pm. 10-11C, mostly clear with some breeze.
Saturday
* England v Romania, Dunedin, 6pm. 12C, cloudy with a few showers.
* New Zealand v France, Auckland, 8.30pm. 13C, some showers, no wind.