Rangiora is situated on the northern part of the Canterbury Plain about 1 mile south of the Ashley River and about 6 miles inland from the coast of Pegasus Bay. The surrounding country is flat but towards the north-west it rises gradually to the outer foothill ranges of the Southern Alps. The South Island Main Trunk railway passes through Rangiora, but the main highway leading north from Christchurch passes east of the town. An access road branches north-west from Woodend (4 miles) and links Rangiora with the highway. Christchurch, the nearest city, is 20 miles south by rail and the same distance by road via Woodend. Kaiapoi is 7 miles south-east by road (6 miles by rail) and provides minor port facilities.

The main primary activities of the district are dairying, fat lamb production, and mixed farming, including the production of wheat, barley, small seeds, peas, and potatoes. A large proportion of the Christchurch town milk supply comes from the district. Fruitgrowing, chiefly apples, and poultry farming, are also carried on. In an area beyond Ashley, about 6 miles north of Rangiora, some 13,700 acres are being developed and afforested by the New Zealand Forest Service. Screened shingle from the bed of the Ashley River, near Rangiora, is used locally and also marketed extensively in Christchurch for making concrete blocks.