Auckland was one of those regions whose net confidence decreased and it did so by a dramatic 24 per cent from a net confidence of 8 per cent in the September quarter to -16 per cent.
The survey also revealed that although Northlanders' confidence in the regional economy has grown, their confidence as consumers has declined along with eight other regions.
The Consumer Confidence Index (CCI) summarises households' expectations for their own financial situation - the benchmark being 100.
In the September quarter of 2017, Northlanders held a consumer confidence index of 110.2 which has now decreased to 108.4.
Westpac chief economist Dominick Stephens suggested that although the agricultural and forestry sectors were performing well, a recent decline in lamb, beef and dairy prices may be starting to dampen households' optimism of the Northland economy.
"Economic confidence may also have been affected by a growing sense of unease over future government policy and how it might impact the agricultural sector in the region," Mr Stephens said.
Tony Collins from Northland Chamber of Commerce also credited the slight decrease in consumer confidence to last year's election and the uncertainty of new policies being introduced.
Mr Collins said it might be a matter of "letting the dust settle" as Northland's economy remains strong with unemployment rates continuing to drop.
"Northland's population is still growing and business confidence is still strong, even if it's not what it used to be."