BOS did -10° 3 years ago this Wednesday. I think that was the first time they did double digits below 0F since 1957.
But as for those yore top tier historical cold shots…those may be gone. The ones that bring sub zero temps to SNE in the afternoon or -10° up here…1855, 1857, 1917, 1933, 1934, 1943, etc. That next tier below like 2023 is still potent though.