OTTAWA -- For the first time since May 9, snow is in the forecast for Ottawa.

After a beautiful, but cool, late October day, the Environment Canada forecast calls for a chance of snow or rain overnight and periods of snow or rain on Monday.

Ottawa could see one centimetre of snow overnight and Monday.

"We are now seeing significantly colder temperatures dropping down to near the freezing mark tonight, allowing for the development of snow," said Ryan Rozinskis, Environment Canada severe weather meteorologist.

"A sign that the season has changed and we are looking at summer in the rear-view mirror."

The forecast also calls for a chance of flurries Monday night and Tuesday.

The last time it snowed in Ottawa was on May 9, when a trace of snow was recorded at the Ottawa Airport. Ottawa received 0.4 cm of snow on May 8.

"Rarely do you get to Halloween without seeing some snow," said Environment Canada Senior Climatologist David Phillips in an interview with CTV News Ottawa on Friday.

The record for greatest snowfall on Oct. 25 is one centimetre of snow, while the Oct. 26 record is 6.8 centimetres, set back in 1997.

Here is a look at the Ottawa forecast:

Tonight: Partly cloudy. Becoming cloudy near midnight with a 60 per cent chance of snow or rain before morning. Low plus 1C.

Monday: Periods of snow or rain changing to rain in the morning. High 3C.

Monday night: Periods of rain ending in the evening then cloudy with a 30 per cent chance of flurries. Low minus 2C.

Tuesday: Cloudy. High 4C. There is a chance of flurries Tuesday night.

Wednesday: Cloudy. High 7C.

Thursday:  A mix of sun and cloud. High 5C.

The normal temperatures for this time of year are a high of 10C and a low of 2C.