"We imagine that the market is braced for a figure close to $4 (kgMS)," said Raiko Shareef, currency strategist at Bank of New Zealand.
"A print at $4.25 or above will likely see further gains for NZD, and perhaps a sustained break of important resistance at 0.6580. Anything below $4.00, and we will likely see another test of 0.65."
Fonterra's board is expected to cut the forecast payout to farmers after global milk prices have extended their slump this year, putting pressure on the nation's terms of trade.
That deterioration prompted New Zealand's central bank to start cutting interest rates in June.
Shareef said the market still expects the Bank of England's rate to rise by a quarter point by mid-2016 but the BoE will likely be beaten by the US Federal Reserve in hiking rates.
Investors may get more of a sense of the Fed's timing with the release of July non-farm payrolls data in the US on Friday.
The local currency traded at 59.94 euro cents from 59.92 cents late yesterday and rose to 81.69 yen from 81.58 yen.
The kiwi was little changed at 89.14 Australian cents from 89.13 cents yesterday, and the trade-weighted index advanced to 69.95 from 69.83.