MONTREAL — The annual opening of the St. Lawrence Seaway is being delayed about a week due to cold weather and heavy ice in sections of the passage.

The 3,700-km waterway from Montreal to mid-Lake Erie is scheduled to open April 2. The seaway typically opens around March 25.

The seaway officially opened March 28 last year at the Welland Canal in St. Catharines, Ont., and March 31 at the Montreal end of the system.

The St. Lawrence Seaway Management Corp. says it made the decision to delay the opening after considering “conditions affecting safe navigation and effective system transit.”