Here's a cool Free Family activities on the weekends especially when the weather doesn't cooperate.  Beaubien cinema is offering free screenings of family movies in the morning from June 25 to September 4.  The movies are in French so keep that in mind in case the little ones don't understand French.
The movies are shown Saturday and Sunday mornings at 10am.  Tickets can be obtained as of 9:30

Here is the schedule for the rest of the summer:

July 23 & 24: Megamind
July 30 & 31: Rango
Aug. 6 & 7: Rio
Aug. 13 & 14: Yogi L'Ours
Aug. 20 & 21: Frissons des Collines
Aug. 27 & 28: Kerity et la Maison des Comptes
Aug. 30 & 31: ?? Surprise ??

Where: Beaubien Cinema,  2396 Beaubien Est, Montreal, H2G 1N2

When: Saturday and Sundays at 10:00 am

Website: http://www.cinemabeaubien.com/fr/evenements.aspx