DULUTH — Not too hot, not too cold: The 33.5 million tons of cargo that moved through the Port of Duluth-Superior in the 2019 shipping season essentially mirrored the five-year average.

Drops in coal and iron ore shipments caused tonnage to drop from last year's 35.9 million tons but were met by record-high wind turbine imports and a good year for grain and other bulk cargoes and commodities.

"Despite some headwinds, it was a solid tonnage season for the Port of Duluth-Superior," Deb DeLuca, executive director of the Duluth Seaway Port Authority, said in a statement.

Iron ore, which accounts for more than half the cargo leaving the port, dropped to 19.6 million tons after hitting a 23-year-high of 21.5 million tons last season.

Coal continued a yearslong decline, driven by a drop in demand, to 8 million tons shipped out over the season, which runs from March to January.

Most of the cargo that moves through the port — ore, coal and grain, which had an upbeat season — arrives by rail and leaves by ship.

It was a strong year for incoming seaway shipments, including a 2% yearly increase in limestone and a jump in salt and freight cargo.

An increasing demand for wind energy brought a record 306,000 freight tons of turbine parts to the port. That eclipsed the 302,000-freight-ton record set in 2008.

"As the farthest inland port in North America, we're geographically well situated to support wind farm installations in the Upper Midwest and central Canada," said Jonathan Lamb, president of Duluth Cargo Connect, in November when the final inbound shipment of parts arrived.

It was a busy year for international shipments overall, with 85 overseas vessels visiting the port, the most since 2010.

Canadian traffic was at its lowest since 2015.

Some of the season's challenges included "international trade conflicts, crop-hindering weather and challenging navigational conditions due to high water levels," the port said.

The port picked up a number of accolades last year and completed a $3.2 million expansion of its intermodal terminal.

Six vessels are laid up and undergoing maintenance at the port this winter.

Given current and predicted conditions, ice-related delays are unlikely when shipping resumes March 25, when the Soo Locks are expected to open.

"Looking ahead, we have reason for optimism in 2020, with the prospect of greater international trade certainty and more project cargo scheduled to arrive," DeLuca said. "The outlook is mostly upbeat."