Although weather is just one factor, it can really affect your travel plans, especially if you're planning an extended stay in Dundas. The hottest months are usually July and August, with an average temperature of 20°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in Dundas are March, January, February and April, with each month seeing an average of 13 cm of snowfall.