Born in Ashburton in 1944, as a young artist Dahlberg studied portraiture and life drawing with Dame Louise Henderson. Today his readily identifiable style is referred to as Regional Surrealism. An ability to simplify form whilst retaining the essence of the place gives a freshness to Dahlberg's New Zealand landscapes. Subtly patterned skies and foregrounds have become something of a trademark.

The recipient of numerous awards Dahlberg has exhibited in Australia and at Pacificart Zug, Switzerland. His work featured in the 2008 exhibition Australasian Landscapes. Paintings are hung in embassies and private collections throughout the USA, Canada, Switzerland, Japan, Holland, and the United Kingdom.