The New Zealand dollar hit US67.52 on Wednesday but recovered yesterday to close trade at US68.17.
Economists predict further fluctuations and for the kiwi to fall further in coming months.
CBA New Zealand economist Chris Tennent-Brown said underlying weaknesses in the local economy would force the kiwi to a range between US60c and US70c and not to levels seen in the last recession when it traded between US40c and US50c.
"The direction of the New Zealand dollar tends to be down," he said.
Mr Tennent-Brown thought it would settle at lower levels, at least until the economy showed signs of recovering.
The US economy, which has been in recession, has shown some recovery apart from the housing, construction and banking sectors, underpinning a stronger greenback.
The other factor to impact on the New Zealand dollar was the Australian economy and its Reserve Bank's take on interest rates.
ANZ chief economist Cameron Bagrie agreed the New Zealand dollar would continue to weaken, saying commodity prices internationally were falling which affected the value of commodity-based currencies.
"The sentiment is for a souring of global growth and we are seeing commodity-based currencies reflecting that by coming under pressure."
The bank's latest commodity price index survey showed a 3.3% decline for August, the largest monthly fall in seven years, with just four commodities increasing in price, seven falling and two remaining unchanged.
The decline in the value of the NZ dollar was greater than the fall in prices, meaning, in NZ-dollar terms, the index rose 2%.
A 7.5% fall in international dairy prices was the catalyst for the size of the decline in the index, with dairy prices falling 18% from last November's peak.
Aluminium recorded the biggest drop at 10.1%, followed by skins at 5.2%, sawn timber, wool kiwifruit and beef.
Apple prices hit a 14-year high and lamb rose 1.6%, followed by logs and seafood.
While the easing currency would force the price of imports higher, Mr Bagrie said in the case of oil, prices had so far tumbled further than the dollar had depreciated.
It was not known whether that would continue, but he said oil prices kept falling despite Russia invading Georgia and hurricanes in the United States.
