The previous high was 1.8 in August 2014.
Businesses are demonstrating confidence in major construction projects, with households feeling more secure about purchasing major items.
Tourism is recovering at a slower rate than other areas.
“The earthquake rebuild will likely continue to underpin further strengthening in the Canterbury labour market as more workers flock to the region. The consequent lift in incomes should continue to underpin healthy discretionary household spending, particularly in big-ticket items,” Nick Tuffley, ASB chief economist, said.
The retail trade indicator was 2.4 in September, compared with 2.2 in August.
The consumer confidence was 0.7 in both August and September.
The consumer spending index was 1.6, up from 1.5 in August.