Does anyone know if the temperatures in Toronto in June are still in the 50's (day time)?
The temperatures in Toronto for June are quiet moderate ranging from 15 C (60s F) to 22 C (mid 70s F)!
Here is daily statistics for 2002-2015 for Toronto City weather station with daily max/min/rainfall,... data from Environment Canada. You can pick different nearby weather station if you want or to go really crazy and switch to hourly data. This should give you more than an adequate answer to your question.
Sorry, all in metric :-)