Sweltering summertime temperatures signal it’s time for road salt deliveries as the Minnesota Department of Transportation prepares for winter.

Semi tractor-trailers have been delivering thousands of tons of road salt this week to MnDOT’s 22 truck stations across the 11 counties in southeastern Minnesota’s District 6. The deliveries are the final deliveries for the fiscal year.

The delivery of road salt to MnDOT is part of the long-term planning that goes into being prepared for the snow and ice season.

Summer is a good time to deliver salt because it is dry and can be moved efficiently to storage areas at each MnDOT truck station. Each truckload is approximately 25 tons. The salt is hauled from Mississippi River barges docked in Winona that bring the salt from mines in Michigan, Missouri or Kansas.

In the past year, MnDOT District 6 has received 37,426 tons of road salt to its facilities. The cost is about $2.9 million. The Rochester truck station, for example, is receiving 3,000 tons during the current deliveries.

Once the salt is delivered, a sample of each truckload is tested by MnDOT’s District 6 materials lab for moisture, size and impurities. The lab will test about 2,000 salt samples to ensure that it is receiving quality material.