I agree completely -- 5 days ago my bike commute took me through 6 inches of snow. The day after, -25°F (-31.6°C) windchills. Your body gets used to the cold if you bike every day as winter sets in. There really is nothing like putting on the thermal underwear + face mask and pedaling home. Keeps one's spirits up during these short winter days.
If anything, hot summer days are harder. After all, you can always add layers if it gets colder, but public decency suggests that removing layers caps out at shorts and t-shirt.
