OTTAWA -- It may technically still be summer, but things are going to get frosty in the Ottawa Valley Thursday night.

Environment Canada has issued a frost advisory for much of the Valley, warning that frost may damage some crops.

The advisory applies to Barry’s Bay, Killaloe, Petawawa, Pembroke, Cobden, Renfrew, Arnprior and Calabogie.

“Patchy frost is likely tonight into Friday morning across portions of northeastern and central Ontario,” the advisory says.

Ground temperatures could fall to near or below the freezing mark.

The weather agency is warning people to cover up plants, especially those in frost-prone areas.