While Rogers Centre strives to make the comfort of our guests a priority when it comes to the opening and/or closing of our roof, there are certain limitations and conditions we must adhere to prior to making a decision to do so -- the four main reasons being temperature, wind, rain and snow.
The retractable roof operating system was designed to operate at or above temperatures of 10 degrees Celsius. Attempting to open or close the roof at temperatures below this mark could easily lead to mechanical failure. Additionally - the mechanical systems within the stadium are not winterized and, as such, opening or closing in temperatures that approach zero Celsius would likely result in major damage.
Wind is an important factor to consider when deciding to open or close the Rogers Centre roof. A wind speed approaching and/or exceeding 64 km/h, for example, would most certainly cause damage to the roof panels and possibly the rail system that holds them. Also -- depending on temperatures -- we might factor in the fact that any wind above 20 km/h would have a cooling effect on guests within the facility.
If the possibility of precipitation over Rogers Centre is 75% or greater - a decision is generally made to have the roof closed so as to keep our guests comfortable and dry.
An accumulation of snow on the retractable roof panels affects their movement - endangering the integrity of the panels themselves and placing strain on the equipment that rotates them. An effort to open or close the roof under these conditions would likely cause significant damage, and is therefore - not attempted.