Coldest I've experienced was Winter of '95. We had 10 days where we never got close to zero. We had temps in the mid -20s overnight, daytime highs of -10. Had a stickshift at the time and it was stiff. Wife had a diesel rabbit that wouldn't start unless we plugged it in an hour before in the morning. Even took the extension with her and parked near the loading docks at work during the day.
I've always found it ironic that I've spent time in Iceland, also been to Norway above the Arctic Circle, and was nowhere near as cold.
Now, this year, we're mid-January and enjoying mid-40s. Supposed to hit 50F Saturday. Nuts. 3 years ago, we had coldest Winter on record (overall, not specific temps).