OTTAWA -- A sunny final few days of summer is in the forecast for Ottawa, but it will be cool overnight.

A frost advisory remains in effect for Ottawa and eastern Ontario.

Environment Canada says patchy frost is expected to develop tonight into Monday morning.

"Take preventative measures to protect frost-sensitive plants and trees."

Here is a look at the forecast for Ottawa.

Today: Sunny today. High 16C

Tonight: Clear. Low 0C with frost

Monday: Mainly sunny. High 17C

Tuesday: Sunny. High 20C

Wednesday. Sunny. High 23C.

Fall officially arrives in Ottawa on Tuesday.