OTTAWA -- Cover those plants up, if you haven’t already. The official last night of summer is bringing some frost.

Environment Canada has issued a frost advisory for Ottawa, with “patchy frost” expected as temperatures fall to 0 C.

The advisory also applies to Gatineau, Brockville-Leeds-Grenville, Prescott and Russell, Cornwall-Morrisburg, and Smiths Falls-Perth-Lanark County.

The frost isn’t expected to return anytime soon, with warmer-than-average temperatures in the forecast for the rest of the week.

Fall officially begins at 9:31 a.m. on Tuesday.