Our whether in Northwestern Ontario Canada will start the warming trend in the month of May. All snow will be melted away and most lakes will be completely clear of ice. Warm days in the 60s to70s will be on us around the beginning of June. Near the end of June to the end of August is the time for summer pleasures.eg. swimming, skiing etc. The temp can reach the 100s at times. September remains very comfortable. Nearing the end of this month will usually bring that sence that fall is in the air.