July 1 in Montreal is not only associated with Canada Day, but it's also National Moving Day, when tens of thousands of people swap living spaces.

According to surveys from last year and information from landlords, the Quebec Landlords Association estimates that 100,000 tenants moved in Montreal this July 1.

Availability rates are calculated based on the amount of free units within a building and ones that will be available to lease as of July 1.

Vacancy rates are calculated based on the amount of empty units within a building.

As it stands, the apartment availability rate in the city is just above four per cent, but Quebec's largest association of landlords is warning that a housing crisis is on the way.

"We will have a major problem in the coming years," said Hans Brouillette, a spokesman for the association.

The association says Montreal's last housing crisis was felt in 2000, when the availability rate shrank to one per cent.

Brouillette said the vacancy rate has climbed at a glacial but steady pace since 2000, thanks to low interest rates and a trend toward home ownership.

However, he said as interest rates begin to increase and no new rental units are built, the market could feel the pinch of a housing crisis.