The New Zealand dollar is heading for a 2.5 per cent fall against the greenback in August, as it softened further at the end of the week.
The kiwi traded 77.72 US cents at 5pm in Wellington from 77.73 cents at 8am, down from 78.32 cents on Thursday.
The trade-weighted index fell to 73.69 from 74.01 on Thursday, and is heading for a 3.3 per cent fall from the start of the month.
The kiwi was under pressure all month amid:
* growing expectations the Federal Reserve will start pulling back its stimulus
* a sell-off in emerging markets as developing economies start slowing
* Fonterra's food scare.
The prospect of a Western-led military strike on Syria in retaliation for attacking civilians with chemical weapons has also put markets on the back-foot.
"If we're right and the Fed is going to be tapering in September, I think the US dollar will probably firm," said Chris Tennent-Brown, FX economist at Commonwealth Bank of Australia in Sydney.
The NZ currency fell to 86.91 Australian cents at 5pm in Wellington from 87.27 cents on Thursday, to 76.40 yen from 76.57 yen and to 58.70 euro cents from 58.80 cents.