The deficit expanded to C$3.41 billion ($2.73 billion), the fifth largest on record, from a revised C$2.98 billion shortfall in July and exceeded the C$2.60 billion forecast by analysts in a Reuters poll.
Exports of radioactive ores and concentrates, meanwhile, fell after the shutdowns of uranium refining facilities.
Canada's trade deficit widened in August to Can$3.4 billion (US$2.7 billion) on falling exports, the government statistical agency said Thursday. "August exports were $195.3 billion, $0.8 billion more than July exports", the Census Bureau and the Bureau of Economic Analysis said in a monthly report. Notably the Canadian dollar gained 0.5 cents U.S. from July to August.
The Canadian economy roared through the first six months of the year.
Kavcic said the trade results were "another argument for the Bank of Canada to take a breather".
Jacques Dubochet, Joachim Frank, Richard Henderson Win Prestigious Award
Dubochet was born in 1942 in Switzerland and is based at the University of Lausanne, where he is honorary professor of biophysics. The use of both techniques was, however, subject to limitations imposed by the nature of biomolecules.
The goods deficit decreased 1.3%, lowering to $64.4 billion, while the services surplus jumped 1.4% to $22.0 billion.
The drop came as exports of consumer goods and basic and industrial chemical, plastic and rubber products, as well as metal ores and non-metallic minerals moved lower.
Exports of goods increased a slight $600 million, while imports of goods decreased $300 million, underpinned by volatility in the energy category.
TD Bank economist Dina Ignjatovic said, going forward, a healthy USA economy should help to prop up demand for Canadian-made goods, supporting export volumes. The gap in goods with Mexico climbed 26 percent to $6.2 billion in August, and the goods deficit with China rose 4 percent to $34.9 billion.