Like far too many exhibits at the Toronto Zoo, I don't think that the meerkats have an outdoor area. In some years in eastern Canada there are weeks of snow, and so a zoo like Toronto has at least 7 or 8 huge pavilions that house a good chunk of their animals. This is why the Toronto Zoo can't really even come close to a zoo like San Diego, or any other southern zoo in a warmer climate.
The meerkats and most animals at the TZ have access to outside exhibits. The main ones that don't are the Mandrills (which have and off exhibit yard outside at the zoo) and the Orangutans which will have one in 2013. The Meerkats are carried outside to a pen that they have set up in the summer.