The ANZ Bank's monthly commodity price index has risen for the sixth consecutive month.
The index climbed 4.3% in August - driven largely by rising prices for aluminum and pelts.
However, when converted back into New Zealand dollars, the index was down 0.7% on July.
ANZ economist Steve Edwards says the gain is yet to translate to farm-gate returns.
The index covers price movements in 13 commodities - mainly agricultural - including dairy, meat, timber and aluminum.