Geographically Toronto is a pretty big place. Where were the weather stations? Typically at airports because the need for accurate weather is greater there. However you may have intermediate weather stations throughout the city that vary by a considerable margin. Plus if the WS is near buildings and pavement, the temperature is going to be warmer no matter what.

In my little city of Regina, I live on the east end, airport is on the west end and the difference in weather is often considerable. It can be bone dry at the airport and a complete deluge of rain on the north-east. This has happened a couple of times where I've been able to physically verify it by driving through town.