This is my first Boston winter. down to about 25-30 and dry, a nice midweight, cotton/poly blend long underwear and jeans are fine. I just rode 4 miles in the first real snow of the year, with that and a pair of $35 Columbia rain paints, and was very toasty at 23 degrees with a windchill of 6, riding into the wind. I have a cheap pair of snow pants for when it gets really cold.