There’s going to be a weather whiplash for many parts of Ontario Tuesday, as temperatures are forecast to go up and down within the day. It all starts with a warm front linked to a Colorado low that will bring southwest winds into the province. This will have a huge impact on temperatures, bringing a humid airmass into the Great Lakes. It’s going to feel like summer in April as temperatures will soar into the upper 20s, with humidex values into the 30s.