A fog advisory is in effect for Hamilton, as well as the regions of York, Peel, Halton and Durham with Environment Canada warning of near zero visibility in some areas.
With warmer temperatures and "significant" rainfall set to arrive in southern Ontario on Tuesday and Wednesday, officials say there is an increased chance of localized flooding. Visibilities will be frequently reduced to less than 800 metres at times.
Significant rainfall is expected to start later today in the evening, according to a recent special weather statement from Environment Canada. "The first steady period of rain will begin this evening and last into Tuesday morning, so that could slow down the commute", Hull said. EC warns that the rain, combined with rapidly melting snow due to warmer temperatures, may cause a build up or ponding of water in poorly drained areas.
This is below Environment Canada's criterion for rainfall warning when the ground is frozen.
It could be a record-breaker on Tuesday with the daytime high expected to reach 15 C; rain will continue to dominate.
Additional rainfall amounts of 20mm to 30mm are likely.